mirror of https://gitee.com/bigwinds/arangodb
1987 lines
67 KiB
JavaScript
1987 lines
67 KiB
JavaScript
/* global ArangoServerState, ArangoClusterInfo */
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'use strict';
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// //////////////////////////////////////////////////////////////////////////////
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// / @brief JavaScript cluster functionality
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// /
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// / @file
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// /
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// / DISCLAIMER
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// /
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// / Copyright 2012 triagens GmbH, Cologne, Germany
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// /
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// / Licensed under the Apache License, Version 2.0 (the "License")
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// / you may not use this file except in compliance with the License.
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// / You may obtain a copy of the License at
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// /
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// / http://www.apache.org/licenses/LICENSE-2.0
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// /
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// / Unless required by applicable law or agreed to in writing, software
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// / distributed under the License is distributed on an "AS IS" BASIS,
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// / WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// / See the License for the specific language governing permissions and
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// / limitations under the License.
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// /
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// / Copyright holder is triAGENS GmbH, Cologne, Germany
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// /
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// / @author Jan Steemann
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// / @author Copyright 2012, triAGENS GmbH, Cologne, Germany
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// //////////////////////////////////////////////////////////////////////////////
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var console = require('console');
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var arangodb = require('@arangodb');
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var ArangoCollection = arangodb.ArangoCollection;
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var ArangoError = arangodb.ArangoError;
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var errors = require("internal").errors;
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var request = require('@arangodb/request').request;
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var wait = require('internal').wait;
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var _ = require('lodash');
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var endpointToURL = function (endpoint) {
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if (endpoint.substr(0, 6) === 'ssl://') {
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return 'https://' + endpoint.substr(6);
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}
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var pos = endpoint.indexOf('://');
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if (pos === -1) {
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return 'http://' + endpoint;
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}
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return 'http' + endpoint.substr(pos);
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};
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// //////////////////////////////////////////////////////////////////////////////
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// / @brief create and post an AQL query that will fetch a READ lock on a
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// / collection and will time out after a number of seconds
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// //////////////////////////////////////////////////////////////////////////////
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function startReadLockOnLeader (endpoint, database, collName, timeout) {
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var url = endpointToURL(endpoint) + '/_db/' + database;
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var r = request({ url: url + '/_api/replication/holdReadLockCollection',
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method: 'GET' });
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if (r.status !== 200) {
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console.error('startReadLockOnLeader: Could not get ID for shard',
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collName, r);
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return false;
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}
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try {
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r = JSON.parse(r.body);
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} catch (err) {
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console.error('startReadLockOnLeader: Bad response body from',
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'/_api/replication/holdReadLockCollection', r,
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JSON.stringify(err));
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return false;
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}
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const id = r.id;
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var body = { 'id': id, 'collection': collName, 'ttl': timeout };
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r = request({ url: url + '/_api/replication/holdReadLockCollection',
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body: JSON.stringify(body),
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method: 'POST', headers: {'x-arango-async': 'store'} });
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if (r.status !== 202) {
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console.error('startReadLockOnLeader: Could not start read lock for shard',
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collName, r);
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return false;
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}
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var rr = r; // keep a copy
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var count = 0;
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while (++count < 20) { // wait for some time until read lock established:
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// Now check that we hold the read lock:
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r = request({ url: url + '/_api/replication/holdReadLockCollection',
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body: JSON.stringify(body),
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method: 'PUT' });
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if (r.status === 200) {
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return id;
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}
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console.debug('startReadLockOnLeader: Do not see read lock yet...');
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wait(0.5);
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}
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var asyncJobId = rr.headers['x-arango-async-id'];
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r = request({ url: url + '/_api/job/' + asyncJobId, body: '', method: 'PUT'});
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console.error('startReadLockOnLeader: giving up, async result:', r);
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return false;
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}
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// //////////////////////////////////////////////////////////////////////////////
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// / @brief cancel such a query, return whether or not the query was found
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// //////////////////////////////////////////////////////////////////////////////
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function cancelReadLockOnLeader (endpoint, database, lockJobId) {
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var url = endpointToURL(endpoint) + '/_db/' + database +
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'/_api/replication/holdReadLockCollection';
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var r;
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var body = {'id': lockJobId};
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try {
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r = request({url, body: JSON.stringify(body), method: 'DELETE' });
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} catch (e) {
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console.error('cancelReadLockOnLeader: exception caught:', e);
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return false;
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}
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if (r.status !== 200) {
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console.error('cancelReadLockOnLeader: error', r);
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return false;
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}
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console.debug('cancelReadLockOnLeader: success');
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return true;
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}
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// //////////////////////////////////////////////////////////////////////////////
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// / @brief cancel barrier from sync
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// //////////////////////////////////////////////////////////////////////////////
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function cancelBarrier (endpoint, database, barrierId) {
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var url = endpointToURL(endpoint) + '/_db/' + database +
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'/_api/replication/barrier/' + barrierId;
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var r = request({url, method: 'DELETE' });
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if (r.status !== 200 && r.status !== 204) {
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console.error('CancelBarrier: error', r);
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return false;
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}
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console.debug('cancelBarrier: success');
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return true;
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}
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// //////////////////////////////////////////////////////////////////////////////
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// / @brief tell leader that we are in sync
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// //////////////////////////////////////////////////////////////////////////////
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function addShardFollower (endpoint, database, shard) {
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console.debug('addShardFollower: tell the leader to put us into the follower list...');
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var url = endpointToURL(endpoint) + '/_db/' + database +
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'/_api/replication/addFollower';
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var body = {followerId: ArangoServerState.id(), shard};
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var r = request({url, body: JSON.stringify(body), method: 'PUT'});
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if (r.status !== 200) {
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console.error("addShardFollower: could not add us to the leader's follower list.", r);
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return false;
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}
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return true;
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}
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// //////////////////////////////////////////////////////////////////////////////
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// / @brief tell leader that we are stop following
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// //////////////////////////////////////////////////////////////////////////////
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function removeShardFollower (endpoint, database, shard) {
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console.debug('removeShardFollower: tell the leader to take us off the follower list...');
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var url = endpointToURL(endpoint) + '/_db/' + database +
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'/_api/replication/removeFollower';
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var body = {followerId: ArangoServerState.id(), shard};
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var r = request({url, body: JSON.stringify(body), method: 'PUT'});
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if (r.status !== 200) {
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console.error("removeShardFollower: could not remove us from the leader's follower list.", r);
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return false;
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}
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return true;
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}
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// //////////////////////////////////////////////////////////////////////////////
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// / @brief lookup for 4-dimensional nested dictionary data
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// //////////////////////////////////////////////////////////////////////////////
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function lookup4d (data, a, b, c) {
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if (!data.hasOwnProperty(a)) {
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return undefined;
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}
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if (!data[a].hasOwnProperty(b)) {
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return undefined;
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}
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if (!data[a][b].hasOwnProperty(c)) {
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return undefined;
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}
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return data[a][b][c];
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}
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// //////////////////////////////////////////////////////////////////////////////
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// / @brief return a shardId => server map
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// //////////////////////////////////////////////////////////////////////////////
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function getShardMap (plannedCollections) {
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var shardMap = { };
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var database;
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for (database in plannedCollections) {
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if (plannedCollections.hasOwnProperty(database)) {
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var collections = plannedCollections[database];
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var collection;
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for (collection in collections) {
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if (collections.hasOwnProperty(collection)) {
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var shards = collections[collection].shards;
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var shard;
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for (shard in shards) {
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if (shards.hasOwnProperty(shard)) {
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shardMap[shard] = shards[shard];
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}
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}
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}
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}
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}
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}
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return shardMap;
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}
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// //////////////////////////////////////////////////////////////////////////////
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// / @brief return the indexes of a collection as a map
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// //////////////////////////////////////////////////////////////////////////////
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function getIndexMap (shard) {
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var indexes = { }, i;
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var idx = arangodb.db._collection(shard).getIndexes();
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for (i = 0; i < idx.length; ++i) {
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// fetch id without collection name
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var id = idx[i].id.replace(/^[a-zA-Z0-9_\-]*?\/([0-9]+)$/, '$1');
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idx[i].id = id;
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indexes[id] = idx[i];
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}
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return indexes;
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}
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// //////////////////////////////////////////////////////////////////////////////
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// / @brief return a hash with the local databases
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// //////////////////////////////////////////////////////////////////////////////
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function getLocalDatabases () {
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var result = { };
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var db = require('internal').db;
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db._databases().forEach(function (database) {
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result[database] = { name: database };
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});
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return result;
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}
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// //////////////////////////////////////////////////////////////////////////////
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// / @brief return a hash with the local collections
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// //////////////////////////////////////////////////////////////////////////////
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function getLocalCollections () {
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var result = { };
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var db = require('internal').db;
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db._collections().forEach(function (collection) {
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var name = collection.name();
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if (name.substr(0, 1) !== '_') {
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var data = {
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id: collection._id,
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name: name,
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type: collection.type(),
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status: collection.status(),
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planId: collection.planId()
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};
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// merge properties
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var properties = collection.properties();
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var p;
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for (p in properties) {
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if (properties.hasOwnProperty(p)) {
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data[p] = properties[p];
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}
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}
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result[name] = data;
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}
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});
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return result;
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}
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// //////////////////////////////////////////////////////////////////////////////
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// / @brief create databases if they exist in the plan but not locally
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// //////////////////////////////////////////////////////////////////////////////
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function createLocalDatabases (plannedDatabases, currentDatabases, writeLocked) {
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var ourselves = global.ArangoServerState.id();
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var createDatabaseAgency = function (payload) {
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global.ArangoAgency.set('Current/Databases/' + payload.name + '/' + ourselves,
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payload);
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};
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var db = require('internal').db;
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db._useDatabase('_system');
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var localDatabases = getLocalDatabases();
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var name;
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// check which databases need to be created locally
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for (name in plannedDatabases) {
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if (plannedDatabases.hasOwnProperty(name)) {
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var payload = plannedDatabases[name];
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payload.error = false;
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payload.errorNum = 0;
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payload.errorMessage = 'no error';
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if (!localDatabases.hasOwnProperty(name)) {
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// must create database
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// TODO: handle options and user information
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console.debug("creating local database '%s'", payload.name);
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try {
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db._createDatabase(payload.name);
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payload.error = false;
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payload.errorNum = 0;
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payload.errorMessage = 'no error';
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} catch (err) {
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payload.error = true;
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payload.errorNum = err.errorNum;
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payload.errorMessage = err.errorMessage;
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}
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writeLocked({ part: 'Current' },
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createDatabaseAgency,
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[ payload ]);
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} else if (typeof currentDatabases[name] !== 'object' || !currentDatabases[name].hasOwnProperty(ourselves)) {
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// mop: ok during cluster startup we have this buggy situation where a dbserver
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// has a database but has not yet announced it to the agency :S
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writeLocked({ part: 'Current' },
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createDatabaseAgency,
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[ payload ]);
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}
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}
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}
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}
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// //////////////////////////////////////////////////////////////////////////////
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// / @brief drop databases if they do exist locally but not in the plan
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// //////////////////////////////////////////////////////////////////////////////
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function dropLocalDatabases (plannedDatabases, writeLocked) {
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var ourselves = global.ArangoServerState.id();
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var dropDatabaseAgency = function (payload) {
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try {
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global.ArangoAgency.remove('Current/Databases/' + payload.name + '/' + ourselves);
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} catch (err) {
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// ignore errors
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}
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};
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var db = require('internal').db;
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db._useDatabase('_system');
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var localDatabases = getLocalDatabases();
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var name;
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// check which databases need to be deleted locally
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for (name in localDatabases) {
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if (localDatabases.hasOwnProperty(name)) {
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if (!plannedDatabases.hasOwnProperty(name) && name.substr(0, 1) !== '_') {
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// must drop database
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console.info("dropping local database '%s'", name);
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// Do we have to stop a replication applier first?
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if (ArangoServerState.role() === 'SECONDARY') {
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try {
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db._useDatabase(name);
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var rep = require('@arangodb/replication');
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var state = rep.applier.state();
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if (state.state.running === true) {
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console.info('stopping replication applier first');
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rep.applier.stop();
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}
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}
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finally {
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db._useDatabase('_system');
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}
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}
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db._dropDatabase(name);
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writeLocked({ part: 'Current' },
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dropDatabaseAgency,
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[ { name: name } ]);
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}
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}
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}
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}
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// //////////////////////////////////////////////////////////////////////////////
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// / @brief clean up what's in Current/Databases for ourselves
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// //////////////////////////////////////////////////////////////////////////////
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function cleanupCurrentDatabases (currentDatabases, writeLocked) {
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var ourselves = global.ArangoServerState.id();
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var dropDatabaseAgency = function (payload) {
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try {
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global.ArangoAgency.remove('Current/Databases/' + payload.name + '/' + ourselves);
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} catch (err) {
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// ignore errors
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}
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};
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var db = require('internal').db;
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db._useDatabase('_system');
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var localDatabases = getLocalDatabases();
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var name;
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for (name in currentDatabases) {
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if (currentDatabases.hasOwnProperty(name) && name.substr(0, 1) !== '_') {
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if (!localDatabases.hasOwnProperty(name)) {
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// we found a database we don't have locally
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if (currentDatabases[name].hasOwnProperty(ourselves)) {
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// we are entered for a database that we don't have locally
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console.debug("cleaning up entry for unknown database '%s'", name);
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writeLocked({ part: 'Current' },
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dropDatabaseAgency,
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[ { name: name } ]);
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}
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}
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}
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}
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}
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// //////////////////////////////////////////////////////////////////////////////
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// / @brief handle database changes
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// //////////////////////////////////////////////////////////////////////////////
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function handleDatabaseChanges (plan, current, writeLocked) {
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var plannedDatabases = plan.Databases;
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var currentDatabases = current.Databases;
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createLocalDatabases(plannedDatabases, currentDatabases, writeLocked);
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dropLocalDatabases(plannedDatabases, writeLocked);
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cleanupCurrentDatabases(currentDatabases, writeLocked);
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}
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// //////////////////////////////////////////////////////////////////////////////
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// / @brief create collections if they exist in the plan but not locally
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// //////////////////////////////////////////////////////////////////////////////
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function createLocalCollections (plannedCollections, planVersion,
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currentCollections,
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takeOverResponsibility, writeLocked) {
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var ourselves = global.ArangoServerState.id();
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var createCollectionAgency = function (database, shard, collInfo, error) {
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var payload = { error: error.error,
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errorNum: error.errorNum,
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errorMessage: error.errorMessage,
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indexes: collInfo.indexes,
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servers: [ ourselves ],
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planVersion: planVersion };
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global.ArangoAgency.set('Current/Collections/' + database + '/' +
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collInfo.planId + '/' + shard,
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payload);
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};
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var takeOver = createCollectionAgency;
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var db = require('internal').db;
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db._useDatabase('_system');
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var migrate = writeLocked => {
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var localDatabases = getLocalDatabases();
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var database;
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var i;
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// iterate over all matching databases
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for (database in plannedCollections) {
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if (plannedCollections.hasOwnProperty(database)) {
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if (localDatabases.hasOwnProperty(database)) {
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// switch into other database
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db._useDatabase(database);
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try {
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// iterate over collections of database
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var localCollections = getLocalCollections();
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var collections = plannedCollections[database];
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// diff the collections
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Object.keys(collections).forEach(function (collection) {
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var collInfo = collections[collection];
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var shards = collInfo.shards;
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var shard;
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collInfo.planId = collInfo.id;
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var save = [collInfo.id, collInfo.name];
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delete collInfo.id; // must not actually set it here
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delete collInfo.name; // name is now shard
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for (shard in shards) {
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if (shards.hasOwnProperty(shard)) {
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var didWrite = false;
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if (shards[shard].indexOf(ourselves) >= 0) {
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var isLeader = shards[shard][0] === ourselves;
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var wasLeader = isLeader;
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try {
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var currentServers = currentCollections[database][collection][shard].servers;
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wasLeader = currentServers[0] === ourselves;
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} catch(err) {}
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// found a shard we are responsible for
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var error = { error: false, errorNum: 0,
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errorMessage: 'no error' };
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if (!localCollections.hasOwnProperty(shard)) {
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// must create this shard
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console.debug("creating local shard '%s/%s' for central '%s/%s'",
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database,
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shard,
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database,
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collInfo.planId);
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try {
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if (collInfo.type === ArangoCollection.TYPE_EDGE) {
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db._createEdgeCollection(shard, collInfo);
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} else {
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db._create(shard, collInfo);
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}
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} catch (err2) {
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error = { error: true, errorNum: err2.errorNum,
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errorMessage: err2.errorMessage };
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console.error("creating local shard '%s/%s' for central '%s/%s' failed: %s",
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database,
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shard,
|
|
database,
|
|
collInfo.planId,
|
|
JSON.stringify(err2));
|
|
}
|
|
|
|
if (isLeader) {
|
|
writeLocked({ part: 'Current' },
|
|
createCollectionAgency,
|
|
[ database, shard, collInfo, error ]);
|
|
didWrite = true;
|
|
}
|
|
} else {
|
|
if (!isLeader && wasLeader) {
|
|
db._collection(shard).leaderResign();
|
|
}
|
|
|
|
if (localCollections[shard].status !== collInfo.status) {
|
|
console.info("detected status change for local shard '%s/%s'",
|
|
database,
|
|
shard);
|
|
|
|
if (collInfo.status === ArangoCollection.STATUS_UNLOADED) {
|
|
console.info("unloading local shard '%s/%s'",
|
|
database,
|
|
shard);
|
|
db._collection(shard).unload();
|
|
} else if (collInfo.status === ArangoCollection.STATUS_LOADED) {
|
|
console.info("loading local shard '%s/%s'",
|
|
database,
|
|
shard);
|
|
db._collection(shard).load();
|
|
}
|
|
if (isLeader) {
|
|
writeLocked({ part: 'Current' },
|
|
createCollectionAgency,
|
|
[ database, shard, collInfo, error ]);
|
|
didWrite = true;
|
|
}
|
|
}
|
|
|
|
// collection exists, now compare collection properties
|
|
var properties = { };
|
|
var cmp = [ 'journalSize', 'waitForSync', 'doCompact',
|
|
'indexBuckets' ];
|
|
for (i = 0; i < cmp.length; ++i) {
|
|
var p = cmp[i];
|
|
if (localCollections[shard][p] !== collInfo[p]) {
|
|
// property change
|
|
properties[p] = collInfo[p];
|
|
}
|
|
}
|
|
|
|
if (Object.keys(properties).length > 0) {
|
|
console.info("updating properties for local shard '%s/%s'",
|
|
database,
|
|
shard);
|
|
|
|
try {
|
|
db._collection(shard).properties(properties);
|
|
} catch (err3) {
|
|
error = { error: true, errorNum: err3.errorNum,
|
|
errorMessage: err3.errorMessage };
|
|
}
|
|
if (isLeader) {
|
|
writeLocked({ part: 'Current' },
|
|
createCollectionAgency,
|
|
[ database, shard, collInfo, error ]);
|
|
didWrite = true;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (error.error) {
|
|
if (takeOverResponsibility && !didWrite) {
|
|
if (isLeader) {
|
|
writeLocked({ part: 'Current' },
|
|
takeOver,
|
|
[ database, shard, collInfo, error ]);
|
|
}
|
|
}
|
|
continue; // No point to look for properties and
|
|
// indices, if the creation has not worked
|
|
}
|
|
|
|
var indexes = getIndexMap(shard);
|
|
var idx;
|
|
var index;
|
|
|
|
if (collInfo.hasOwnProperty('indexes')) {
|
|
for (i = 0; i < collInfo.indexes.length; ++i) {
|
|
index = collInfo.indexes[i];
|
|
|
|
var changed = false;
|
|
|
|
if (index.type !== 'primary' && index.type !== 'edge' &&
|
|
!indexes.hasOwnProperty(index.id)) {
|
|
console.debug("creating index '%s/%s': %s",
|
|
database,
|
|
shard,
|
|
JSON.stringify(index));
|
|
|
|
try {
|
|
arangodb.db._collection(shard).ensureIndex(index);
|
|
index.error = false;
|
|
index.errorNum = 0;
|
|
index.errorMessage = '';
|
|
} catch (err5) {
|
|
index.error = true;
|
|
index.errorNum = err5.errorNum;
|
|
index.errorMessage = err5.errorMessage;
|
|
}
|
|
|
|
changed = true;
|
|
}
|
|
if (changed && isLeader) {
|
|
writeLocked({ part: 'Current' },
|
|
createCollectionAgency,
|
|
[ database, shard, collInfo, error ]);
|
|
didWrite = true;
|
|
}
|
|
}
|
|
|
|
var changed2 = false;
|
|
for (idx in indexes) {
|
|
if (indexes.hasOwnProperty(idx)) {
|
|
// found an index in the index map, check if it must be deleted
|
|
|
|
if (indexes[idx].type !== 'primary' && indexes[idx].type !== 'edge') {
|
|
var found = false;
|
|
for (i = 0; i < collInfo.indexes.length; ++i) {
|
|
if (collInfo.indexes[i].id === idx) {
|
|
found = true;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (!found) {
|
|
// found an index to delete locally
|
|
changed2 = true;
|
|
index = indexes[idx];
|
|
|
|
console.info("dropping index '%s/%s': %s",
|
|
database,
|
|
shard,
|
|
JSON.stringify(index));
|
|
|
|
arangodb.db._collection(shard).dropIndex(index);
|
|
|
|
delete indexes[idx];
|
|
collInfo.indexes.splice(i, i);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
if (changed2 && isLeader) {
|
|
writeLocked({ part: 'Current' },
|
|
createCollectionAgency,
|
|
[ database, shard, collInfo, error ]);
|
|
didWrite = true;
|
|
}
|
|
}
|
|
|
|
if ((takeOverResponsibility && !didWrite && isLeader) ||
|
|
(!didWrite && isLeader && !wasLeader)) {
|
|
writeLocked({ part: 'Current' },
|
|
takeOver,
|
|
[ database, shard, collInfo, error ]);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
collInfo.id = save[0];
|
|
collInfo.name = save[1];
|
|
});
|
|
} catch (err) {
|
|
// always return to previous database
|
|
db._useDatabase('_system');
|
|
throw err;
|
|
}
|
|
|
|
db._useDatabase('_system');
|
|
}
|
|
}
|
|
}
|
|
};
|
|
|
|
if (takeOverResponsibility) {
|
|
// mop: if this is a complete takeover we need a global lock because
|
|
// otherwise the coordinator might fetch results which are only partly
|
|
// migrated
|
|
var fakeLock = (lockInfo, cb, args) => {
|
|
if (!lockInfo || lockInfo.part !== 'Current') {
|
|
throw new Error('Invalid lockInfo ' + JSON.stringify(lockInfo));
|
|
}
|
|
return cb(...args);
|
|
};
|
|
writeLocked({ part: 'Current' }, migrate, [fakeLock]);
|
|
} else {
|
|
migrate(writeLocked);
|
|
}
|
|
}
|
|
|
|
function leaderResign (database, collId, shardName, ourselves) {
|
|
console.info("trying to withdraw as leader of shard '%s/%s' of '%s/%s'",
|
|
database, shardName, database, collId);
|
|
try {
|
|
var db = require('internal').db;
|
|
db._executeTransaction(
|
|
{ 'collections': { 'write': [shardName] },
|
|
'action': function () {
|
|
var path = 'Current/Collections/' + database + '/' + collId + '/' +
|
|
shardName + '/servers';
|
|
var servers = global.ArangoAgency.get(path).arango.Current
|
|
.Collections[database][collId][shardName].servers;
|
|
if (servers[0] === ourselves) {
|
|
servers[0] = '_' + ourselves;
|
|
global.ArangoAgency.set(path, servers);
|
|
global.ArangoAgency.increaseVersion('Current/Version');
|
|
}
|
|
} });
|
|
} catch (x) {
|
|
console.error('exception thrown when resigning:', x);
|
|
}
|
|
}
|
|
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
// / @brief drop collections if they exist locally but not in the plan
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
|
|
function dropLocalCollections (plannedCollections, currentCollections,
|
|
writeLocked) {
|
|
var ourselves = global.ArangoServerState.id();
|
|
|
|
var dropCollectionAgency = function (database, shardID, id) {
|
|
try {
|
|
global.ArangoAgency.remove('Current/Collections/' + database + '/' + id + '/' + shardID);
|
|
} catch (err) {
|
|
// ignore errors
|
|
}
|
|
};
|
|
|
|
var db = require('internal').db;
|
|
db._useDatabase('_system');
|
|
var shardMap = getShardMap(plannedCollections);
|
|
|
|
var localDatabases = getLocalDatabases();
|
|
var database;
|
|
|
|
// iterate over all databases
|
|
for (database in localDatabases) {
|
|
if (localDatabases.hasOwnProperty(database)) {
|
|
var removeAll = !plannedCollections.hasOwnProperty(database);
|
|
|
|
// switch into other database
|
|
db._useDatabase(database);
|
|
|
|
try {
|
|
// iterate over collections of database
|
|
var collections = getLocalCollections();
|
|
var collection;
|
|
|
|
for (collection in collections) {
|
|
if (collections.hasOwnProperty(collection)) {
|
|
// found a local collection
|
|
// check if it is in the plan and we are responsible for it
|
|
|
|
var remove = removeAll ||
|
|
(!shardMap.hasOwnProperty(collection)) ||
|
|
(shardMap[collection].indexOf(ourselves) === -1);
|
|
|
|
if (remove) {
|
|
var currentServers;
|
|
// May be we have been the leader and are asked to withdraw:
|
|
if (shardMap.hasOwnProperty(collection) &&
|
|
shardMap[collection][0] === '_' + ourselves) {
|
|
try {
|
|
currentServers = currentCollections[database][collections[collection].planId][collection].servers;
|
|
} catch (err2) {
|
|
currentServers = [];
|
|
}
|
|
if (currentServers[0] === ourselves) {
|
|
leaderResign(database, collections[collection].planId,
|
|
collection, ourselves);
|
|
}
|
|
} else {
|
|
// Remove us from the follower list, this is a best effort,
|
|
// we might actually have been the leader ourselves, in which
|
|
// case we try to unfollow the new leader, no problem, we
|
|
// simply ignore any errors. If a proper error occurs, this
|
|
// is also no problem, since the leader will soon notice
|
|
// that the shard here is gone and will drop us automatically:
|
|
var servers = shardMap[collection];
|
|
try {
|
|
currentServers = currentCollections[database][collections[collection].planId][collection].servers;
|
|
} catch (err2) {
|
|
currentServers = [];
|
|
}
|
|
if (servers !== undefined &&
|
|
currentServers.indexOf(ourselves) >= 0) {
|
|
var endpoint = ArangoClusterInfo.getServerEndpoint(servers[0]);
|
|
try {
|
|
removeShardFollower(endpoint, database, collection);
|
|
} catch (err) {}
|
|
}
|
|
console.info("dropping local shard '%s/%s' of '%s/%s",
|
|
database,
|
|
collection,
|
|
database,
|
|
collections[collection].planId);
|
|
|
|
db._drop(collection);
|
|
|
|
if (removeAll || !shardMap.hasOwnProperty(collection)) {
|
|
console.debug('cleaning out Current entry for shard %s in',
|
|
'agency for %s/%s', collection, database,
|
|
collections[collection].name);
|
|
writeLocked({ part: 'Current' },
|
|
dropCollectionAgency,
|
|
[ database, collection, collections[collection].planId ]);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
} catch (err) {
|
|
db._useDatabase('_system');
|
|
throw err;
|
|
}
|
|
db._useDatabase('_system');
|
|
}
|
|
}
|
|
}
|
|
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
// / @brief clean up what's in Current/Collections for ourselves
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
|
|
function cleanupCurrentCollections (plannedCollections, currentCollections,
|
|
writeLocked) {
|
|
var dropCollectionAgency = function (database, collection, shardID) {
|
|
try {
|
|
global.ArangoAgency.remove('Current/Collections/' + database + '/' + collection + '/' + shardID);
|
|
} catch (err) {
|
|
// ignore errors
|
|
}
|
|
};
|
|
|
|
var db = require('internal').db;
|
|
db._useDatabase('_system');
|
|
|
|
var shardMap = getShardMap(plannedCollections);
|
|
var database;
|
|
|
|
for (database in currentCollections) {
|
|
if (currentCollections.hasOwnProperty(database)) {
|
|
var collections = currentCollections[database];
|
|
var collection;
|
|
|
|
for (collection in collections) {
|
|
if (collections.hasOwnProperty(collection)) {
|
|
var shards = collections[collection];
|
|
var shard;
|
|
|
|
for (shard in shards) {
|
|
if (shards.hasOwnProperty(shard)) {
|
|
if (!shardMap.hasOwnProperty(shard)) {
|
|
// found an entry in current of a shard that is no longer
|
|
// mentioned in the plan
|
|
console.info("cleaning up entry for shard '%s' of '%s/%s",
|
|
shard,
|
|
database,
|
|
collection);
|
|
|
|
writeLocked({ part: 'Current' },
|
|
dropCollectionAgency,
|
|
[ database, collection, shard ]);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
// / @brief lock key space
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
|
|
function lockSyncKeyspace () {
|
|
while (!global.KEY_SET_CAS('shardSynchronization', 'lock', 1, null)) {
|
|
wait(0.001);
|
|
}
|
|
}
|
|
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
// / @brief unlock key space
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
|
|
function unlockSyncKeyspace () {
|
|
global.KEY_SET('shardSynchronization', 'lock', null);
|
|
}
|
|
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
// / @brief launch a scheduled job if needed
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
|
|
function tryLaunchJob () {
|
|
const registerTask = require('internal').registerTask;
|
|
var isStopping = require('internal').isStopping;
|
|
if (isStopping()) {
|
|
return;
|
|
}
|
|
var doCleanup = false;
|
|
lockSyncKeyspace();
|
|
try {
|
|
var jobs = global.KEYSPACE_GET('shardSynchronization');
|
|
if (jobs.running === null) {
|
|
var shards = Object.keys(jobs.scheduled).sort();
|
|
if (shards.length > 0) {
|
|
var done = false;
|
|
while (!done) {
|
|
var jobInfo = jobs.scheduled[shards[0]];
|
|
try {
|
|
registerTask({
|
|
database: jobInfo.database,
|
|
params: {database: jobInfo.database, shard: jobInfo.shard,
|
|
planId: jobInfo.planId, leader: jobInfo.leader},
|
|
command: function (params) {
|
|
require('@arangodb/cluster').synchronizeOneShard(
|
|
params.database, params.shard, params.planId, params.leader);
|
|
}});
|
|
done = true;
|
|
global.KEY_SET('shardSynchronization', 'running', jobInfo);
|
|
console.debug('tryLaunchJob: have launched job', jobInfo);
|
|
delete jobs.scheduled[shards[0]];
|
|
global.KEY_SET('shardSynchronization', 'scheduled', jobs.scheduled);
|
|
} catch (err) {
|
|
if (err.errorNum === errors.ERROR_ARANGO_DATABASE_NOT_FOUND.code) {
|
|
doCleanup = true;
|
|
done = true;
|
|
}
|
|
if (!require('internal').isStopping()) {
|
|
console.error('Could not registerTask for shard synchronization.',
|
|
err);
|
|
wait(1.0);
|
|
} else {
|
|
doCleanup = true;
|
|
done = true;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
finally {
|
|
unlockSyncKeyspace();
|
|
}
|
|
if (doCleanup) { // database was deleted
|
|
global.KEYSPACE_REMOVE("shardSynchronization");
|
|
}
|
|
}
|
|
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
// / @brief synchronize one shard, this is run as a V8 task
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
|
|
function synchronizeOneShard (database, shard, planId, leader) {
|
|
// synchronize this shard from the leader
|
|
// this function will throw if anything goes wrong
|
|
|
|
var isStopping = require('internal').isStopping;
|
|
var ourselves = global.ArangoServerState.id();
|
|
|
|
function terminateAndStartOther () {
|
|
lockSyncKeyspace();
|
|
try {
|
|
global.KEY_SET('shardSynchronization', 'running', null);
|
|
}
|
|
finally {
|
|
unlockSyncKeyspace();
|
|
}
|
|
tryLaunchJob(); // start a new one if needed
|
|
}
|
|
|
|
// First wait until the leader has created the shard (visible in
|
|
// Current in the Agency) or we or the shard have vanished from
|
|
// the plan:
|
|
while (true) {
|
|
if (isStopping()) {
|
|
terminateAndStartOther();
|
|
return;
|
|
}
|
|
var planned = [];
|
|
try {
|
|
planned = global.ArangoClusterInfo.getCollectionInfo(database, planId)
|
|
.shards[shard];
|
|
} catch (e) {}
|
|
if (!Array.isArray(planned) ||
|
|
planned.indexOf(ourselves) <= 0 ||
|
|
planned[0] !== leader) {
|
|
// Things have changed again, simply terminate:
|
|
terminateAndStartOther();
|
|
console.info('synchronizeOneShard: cancelled, %s/%s, %s/%s',
|
|
database, shard, database, planId);
|
|
return;
|
|
}
|
|
var current = [];
|
|
try {
|
|
current = global.ArangoClusterInfo.getCollectionInfoCurrent(
|
|
database, planId, shard).servers;
|
|
} catch (e2) {}
|
|
if (current[0] === leader) {
|
|
if (current.indexOf(ourselves) === -1) {
|
|
break; // start synchronization work
|
|
}
|
|
// We are already there, this is rather strange, but never mind:
|
|
terminateAndStartOther();
|
|
console.info('synchronizeOneShard: already done, %s/%s, %s/%s',
|
|
database, shard, database, planId);
|
|
return;
|
|
}
|
|
console.info('synchronizeOneShard: waiting for leader, %s/%s, %s/%s',
|
|
database, shard, database, planId);
|
|
wait(1.0);
|
|
}
|
|
|
|
// Once we get here, we know that the leader is ready for sync, so
|
|
// we give it a try:
|
|
var ok = false;
|
|
const rep = require('@arangodb/replication');
|
|
|
|
console.debug("synchronizeOneShard: trying to synchronize local shard '%s/%s' for central '%s/%s'", database, shard, database, planId);
|
|
try {
|
|
var ep = ArangoClusterInfo.getServerEndpoint(leader);
|
|
// First once without a read transaction:
|
|
var sy;
|
|
if (isStopping()) {
|
|
throw 'server is shutting down';
|
|
}
|
|
sy = rep.syncCollection(shard,
|
|
{ endpoint: ep, incremental: true,
|
|
keepBarrier: true, useCollectionId: false });
|
|
if (sy.error) {
|
|
console.error('synchronizeOneShard: could not initially synchronize',
|
|
'shard ', shard, sy);
|
|
throw 'Initial sync for shard ' + shard + ' failed';
|
|
} else {
|
|
if (sy.collections.length === 0 ||
|
|
sy.collections[0].name !== shard) {
|
|
cancelBarrier(ep, database, sy.barrierId);
|
|
throw 'Shard ' + shard + ' seems to be gone from leader!';
|
|
} else {
|
|
// Now start a read transaction to stop writes:
|
|
var lockJobId = false;
|
|
try {
|
|
lockJobId = startReadLockOnLeader(ep, database,
|
|
shard, 300);
|
|
console.debug('lockJobId:', lockJobId);
|
|
} catch (err1) {
|
|
console.error('synchronizeOneShard: exception in startReadLockOnLeader:', err1);
|
|
}
|
|
finally {
|
|
cancelBarrier(ep, database, sy.barrierId);
|
|
}
|
|
if (lockJobId !== false) {
|
|
try {
|
|
var sy2 = rep.syncCollectionFinalize(
|
|
database, shard, sy.lastLogTick, { endpoint: ep });
|
|
if (sy2.error) {
|
|
console.error('synchronizeOneShard: Could not finalize shard synchronization',
|
|
shard, sy2);
|
|
ok = false;
|
|
} else {
|
|
ok = addShardFollower(ep, database, shard);
|
|
}
|
|
} catch (err3) {
|
|
console.error('synchronizeOneshard: exception in',
|
|
'syncCollectionFinalize:', err3);
|
|
}
|
|
finally {
|
|
if (!cancelReadLockOnLeader(ep, database,
|
|
lockJobId)) {
|
|
console.error('synchronizeOneShard: read lock has timed out',
|
|
'for shard', shard);
|
|
ok = false;
|
|
}
|
|
}
|
|
} else {
|
|
console.error('synchronizeOneShard: lockJobId was false for shard',
|
|
shard);
|
|
}
|
|
if (ok) {
|
|
console.debug('synchronizeOneShard: synchronization worked for shard',
|
|
shard);
|
|
} else {
|
|
throw 'Did not work for shard ' + shard + '.';
|
|
// just to log below in catch
|
|
}
|
|
}
|
|
}
|
|
} catch (err2) {
|
|
if (!isStopping()) {
|
|
console.error("synchronization of local shard '%s/%s' for central '%s/%s' failed: %s",
|
|
database, shard, database, planId, JSON.stringify(err2));
|
|
}
|
|
}
|
|
// Tell others that we are done:
|
|
terminateAndStartOther();
|
|
console.debug('synchronizeOneShard: done, %s/%s, %s/%s',
|
|
database, shard, database, planId);
|
|
}
|
|
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
// / @brief schedule a shard synchronization
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
|
|
function scheduleOneShardSynchronization (database, shard, planId, leader) {
|
|
console.debug('scheduleOneShardSynchronization:', database, shard, planId,
|
|
leader);
|
|
try {
|
|
global.KEY_GET('shardSynchronization', 'lock');
|
|
} catch (e) {
|
|
global.KEYSPACE_CREATE('shardSynchronization');
|
|
global.KEY_SET('shardSynchronization', 'scheduled', {});
|
|
global.KEY_SET('shardSynchronization', 'running', null);
|
|
global.KEY_SET('shardSynchronization', 'lock', null);
|
|
}
|
|
|
|
lockSyncKeyspace();
|
|
try {
|
|
var jobs = global.KEYSPACE_GET('shardSynchronization');
|
|
if ((jobs.running !== null && jobs.running.shard === shard) ||
|
|
jobs.scheduled.hasOwnProperty(shard)) {
|
|
console.debug('task is already running or scheduled,',
|
|
'ignoring scheduling request');
|
|
return false;
|
|
}
|
|
|
|
// If we reach this, we actually have to schedule a new task:
|
|
var jobInfo = { database, shard, planId, leader};
|
|
jobs.scheduled[shard] = jobInfo;
|
|
global.KEY_SET('shardSynchronization', 'scheduled', jobs.scheduled);
|
|
console.debug('scheduleOneShardSynchronization: have scheduled job', jobInfo);
|
|
}
|
|
finally {
|
|
unlockSyncKeyspace();
|
|
}
|
|
tryLaunchJob();
|
|
return true;
|
|
}
|
|
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
// / @brief synchronize collections for which we are followers (synchronously
|
|
// / replicated shards)
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
|
|
function synchronizeLocalFollowerCollections (plannedCollections,
|
|
currentCollections) {
|
|
var ourselves = global.ArangoServerState.id();
|
|
|
|
var db = require('internal').db;
|
|
db._useDatabase('_system');
|
|
var localDatabases = getLocalDatabases();
|
|
var database;
|
|
|
|
// iterate over all matching databases
|
|
for (database in plannedCollections) {
|
|
if (plannedCollections.hasOwnProperty(database)) {
|
|
if (localDatabases.hasOwnProperty(database)) {
|
|
// switch into other database
|
|
db._useDatabase(database);
|
|
|
|
try {
|
|
// iterate over collections of database
|
|
var collections = plannedCollections[database];
|
|
var collection;
|
|
|
|
// diff the collections
|
|
for (collection in collections) {
|
|
if (collections.hasOwnProperty(collection)) {
|
|
var collInfo = collections[collection];
|
|
var shards = collInfo.shards; // this is the Plan
|
|
var shard;
|
|
|
|
collInfo.planId = collInfo.id;
|
|
|
|
for (shard in shards) {
|
|
if (shards.hasOwnProperty(shard)) {
|
|
var pos = shards[shard].indexOf(ourselves);
|
|
if (pos > 0) { // found and not in position 0
|
|
// found a shard we have to replicate synchronously
|
|
// now see whether we are in sync by looking at the
|
|
// current entry in the agency:
|
|
var inCurrent = lookup4d(currentCollections, database,
|
|
collection, shard);
|
|
// If inCurrent is not in order in any way, we schedule
|
|
// a synchronization job:
|
|
if (inCurrent === undefined ||
|
|
!inCurrent.hasOwnProperty('servers') ||
|
|
typeof inCurrent.servers !== 'object' ||
|
|
!Array.isArray(inCurrent.servers) ||
|
|
inCurrent.servers.indexOf(ourselves) <= 0 ||
|
|
inCurrent.servers[0].substr(0, 1) === '_' ||
|
|
inCurrent.servers[0] !== shards[shard][0]) {
|
|
scheduleOneShardSynchronization(
|
|
database, shard, collInfo.planId, shards[shard][0]);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
} catch (err) {
|
|
// always return to previous database
|
|
db._useDatabase('_system');
|
|
throw err;
|
|
}
|
|
|
|
db._useDatabase('_system');
|
|
}
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
// / @brief handle collection changes
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
|
|
function handleCollectionChanges (plan, current, takeOverResponsibility,
|
|
writeLocked) {
|
|
var plannedCollections = plan.Collections;
|
|
var currentCollections = current.Collections;
|
|
|
|
var ok = true;
|
|
|
|
try {
|
|
createLocalCollections(plannedCollections, plan.Version, currentCollections,
|
|
takeOverResponsibility, writeLocked);
|
|
dropLocalCollections(plannedCollections, currentCollections, writeLocked);
|
|
cleanupCurrentCollections(plannedCollections, currentCollections,
|
|
writeLocked);
|
|
if (!synchronizeLocalFollowerCollections(plannedCollections,
|
|
currentCollections)) {
|
|
// If not all needed jobs have been scheduled, then work is still
|
|
// ongoing, therefore we want to revisit this soon.
|
|
ok = false;
|
|
}
|
|
} catch (err) {
|
|
console.error('Caught error in handleCollectionChanges: ' +
|
|
JSON.stringify(err), JSON.stringify(err.stack));
|
|
ok = false;
|
|
}
|
|
return ok;
|
|
}
|
|
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
// / @brief make sure that replication is set up for all databases
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
|
|
function setupReplication () {
|
|
console.debug('Setting up replication...');
|
|
|
|
var db = require('internal').db;
|
|
var rep = require('@arangodb/replication');
|
|
var dbs = db._databases();
|
|
var i;
|
|
var ok = true;
|
|
for (i = 0; i < dbs.length; i++) {
|
|
var database = dbs[i];
|
|
try {
|
|
console.debug('Checking replication of database ' + database);
|
|
db._useDatabase(database);
|
|
|
|
var state = rep.applier.state();
|
|
if (state.state.running === false) {
|
|
var endpoint = ArangoClusterInfo.getServerEndpoint(
|
|
ArangoServerState.idOfPrimary());
|
|
var config = { 'endpoint': endpoint, 'includeSystem': false,
|
|
'incremental': false, 'autoStart': true,
|
|
'requireFromPresent': true};
|
|
console.info('Starting synchronization...');
|
|
var res = rep.sync(config);
|
|
console.info('Last log tick: ' + res.lastLogTick +
|
|
', starting replication...');
|
|
rep.applier.properties(config);
|
|
var res2 = rep.applier.start(res.lastLogTick);
|
|
console.info('Result of replication start: ' + res2);
|
|
}
|
|
} catch (err) {
|
|
console.error('Could not set up replication for database ', database, JSON.stringify(err));
|
|
ok = false;
|
|
}
|
|
}
|
|
db._useDatabase('_system');
|
|
return ok;
|
|
}
|
|
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
// / @brief role change from secondary to primary
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
|
|
function secondaryToPrimary () {
|
|
console.info('Switching role from secondary to primary...');
|
|
var db = require('internal').db;
|
|
var rep = require('@arangodb/replication');
|
|
var dbs = db._databases();
|
|
var i;
|
|
try {
|
|
for (i = 0; i < dbs.length; i++) {
|
|
var database = dbs[i];
|
|
console.info('Stopping asynchronous replication for db ' +
|
|
database + '...');
|
|
db._useDatabase(database);
|
|
var state = rep.applier.state();
|
|
if (state.state.running === true) {
|
|
try {
|
|
rep.applier.stop();
|
|
} catch (err) {
|
|
console.info('Exception caught whilst stopping replication!');
|
|
}
|
|
}
|
|
rep.applier.forget();
|
|
}
|
|
}
|
|
finally {
|
|
db._useDatabase('_system');
|
|
}
|
|
}
|
|
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
// / @brief role change from primary to secondary
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
|
|
function primaryToSecondary () {
|
|
console.info('Switching role from primary to secondary...');
|
|
}
|
|
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
// / @brief change handling trampoline function
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
|
|
function handleChanges (plan, current, writeLocked) {
|
|
var changed = false;
|
|
var role = ArangoServerState.role();
|
|
if (role === 'PRIMARY' || role === 'SECONDARY') {
|
|
// Need to check role change for automatic failover:
|
|
var myId = ArangoServerState.id();
|
|
if (role === 'PRIMARY') {
|
|
if (!plan.DBServers[myId]) {
|
|
// Ooops! We do not seem to be a primary any more!
|
|
changed = ArangoServerState.redetermineRole();
|
|
}
|
|
} else { // role === "SECONDARY"
|
|
if (plan.DBServers[myId]) {
|
|
changed = ArangoServerState.redetermineRole();
|
|
if (!changed) {
|
|
// mop: oops...changing role has failed. retry next time.
|
|
return false;
|
|
}
|
|
} else {
|
|
var found = null;
|
|
var p;
|
|
for (p in plan) {
|
|
if (plan.hasOwnProperty(p) && plan[p] === myId) {
|
|
found = p;
|
|
break;
|
|
}
|
|
}
|
|
if (found !== ArangoServerState.idOfPrimary()) {
|
|
// Note this includes the case that we are not found at all!
|
|
changed = ArangoServerState.redetermineRole();
|
|
}
|
|
}
|
|
}
|
|
}
|
|
var oldRole = role;
|
|
if (changed) {
|
|
role = ArangoServerState.role();
|
|
console.log('Our role has changed to ' + role);
|
|
if (oldRole === 'SECONDARY' && role === 'PRIMARY') {
|
|
secondaryToPrimary();
|
|
} else if (oldRole === 'PRIMARY' && role === 'SECONDARY') {
|
|
primaryToSecondary();
|
|
}
|
|
}
|
|
|
|
handleDatabaseChanges(plan, current, writeLocked);
|
|
var success;
|
|
if (role === 'PRIMARY' || role === 'COORDINATOR') {
|
|
// Note: This is only ever called for DBservers (primary and secondary),
|
|
// we keep the coordinator case here just in case...
|
|
success = handleCollectionChanges(plan, current, changed, writeLocked);
|
|
} else {
|
|
success = setupReplication();
|
|
}
|
|
|
|
return success;
|
|
}
|
|
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
// / @brief throw an ArangoError
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
|
|
var raiseError = function (code, msg) {
|
|
var err = new ArangoError();
|
|
err.errorNum = code;
|
|
err.errorMessage = msg;
|
|
|
|
throw err;
|
|
};
|
|
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
// / @brief retrieve a list of shards for a collection
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
|
|
var shardList = function (dbName, collectionName) {
|
|
var ci = global.ArangoClusterInfo.getCollectionInfo(dbName, collectionName);
|
|
|
|
if (ci === undefined || typeof ci !== 'object') {
|
|
throw "unable to determine shard list for '" + dbName + '/' + collectionName + "'";
|
|
}
|
|
|
|
var shards = [], shard;
|
|
for (shard in ci.shards) {
|
|
if (ci.shards.hasOwnProperty(shard)) {
|
|
shards.push(shard);
|
|
}
|
|
}
|
|
|
|
if (shards.length === 0) {
|
|
raiseError(arangodb.errors.ERROR_ARANGO_COLLECTION_NOT_FOUND.code,
|
|
arangodb.errors.ERROR_ARANGO_COLLECTION_NOT_FOUND.message);
|
|
}
|
|
|
|
return shards;
|
|
};
|
|
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
// / @brief wait for a distributed response
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
|
|
var waitForDistributedResponse = function (data, numberOfRequests) {
|
|
var received = [];
|
|
try {
|
|
while (received.length < numberOfRequests) {
|
|
var result = global.ArangoClusterComm.wait(data);
|
|
var status = result.status;
|
|
|
|
if (status === 'ERROR') {
|
|
raiseError(arangodb.errors.ERROR_INTERNAL.code,
|
|
'received an error from a DB server: ' + JSON.stringify(result));
|
|
} else if (status === 'TIMEOUT') {
|
|
raiseError(arangodb.errors.ERROR_CLUSTER_TIMEOUT.code,
|
|
arangodb.errors.ERROR_CLUSTER_TIMEOUT.message);
|
|
} else if (status === 'DROPPED') {
|
|
raiseError(arangodb.errors.ERROR_INTERNAL.code,
|
|
'the operation was dropped');
|
|
} else if (status === 'RECEIVED') {
|
|
received.push(result);
|
|
|
|
if (result.headers && result.headers.hasOwnProperty('x-arango-response-code')) {
|
|
var code = parseInt(result.headers['x-arango-response-code'].substr(0, 3), 10);
|
|
|
|
if (code >= 400) {
|
|
var body;
|
|
|
|
try {
|
|
body = JSON.parse(result.body);
|
|
} catch (err) {
|
|
raiseError(arangodb.errors.ERROR_INTERNAL.code,
|
|
'error parsing JSON received from a DB server: ' + err.message);
|
|
}
|
|
|
|
raiseError(body.errorNum,
|
|
body.errorMessage);
|
|
}
|
|
}
|
|
} else {
|
|
// something else... wait without GC
|
|
require('internal').wait(0.1, false);
|
|
}
|
|
}
|
|
} finally {
|
|
global.ArangoClusterComm.drop(data);
|
|
}
|
|
return received;
|
|
};
|
|
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
// / @brief whether or not clustering is enabled
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
|
|
var isCluster = function () {
|
|
var role = global.ArangoServerState.role();
|
|
|
|
return (role !== undefined && role !== 'SINGLE' && role !== 'AGENT');
|
|
};
|
|
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
// / @brief whether or not we are a coordinator
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
|
|
var isCoordinator = function () {
|
|
return global.ArangoServerState.isCoordinator();
|
|
};
|
|
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
// / @brief role
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
|
|
var role = function () {
|
|
var role = global.ArangoServerState.role();
|
|
|
|
if (role !== 'SINGLE') {
|
|
return role;
|
|
}
|
|
return undefined;
|
|
};
|
|
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
// / @brief status
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
|
|
var status = function () {
|
|
if (!isCluster() || !global.ArangoServerState.initialized()) {
|
|
return undefined;
|
|
}
|
|
|
|
return global.ArangoServerState.status();
|
|
};
|
|
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
// / @brief isCoordinatorRequest
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
|
|
var isCoordinatorRequest = function (req) {
|
|
if (!req || !req.hasOwnProperty('headers')) {
|
|
return false;
|
|
}
|
|
|
|
return req.headers.hasOwnProperty('x-arango-coordinator');
|
|
};
|
|
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
// / @brief handlePlanChange
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
|
|
var handlePlanChange = function (plan, current) {
|
|
if (!isCluster() || isCoordinator() || !global.ArangoServerState.initialized()) {
|
|
return true;
|
|
}
|
|
|
|
let versions = {
|
|
plan: plan.Version,
|
|
current: current.Version
|
|
};
|
|
|
|
// ////////////////////////////////////////////////////////////////////////////
|
|
// / @brief execute an action under a write-lock
|
|
// ////////////////////////////////////////////////////////////////////////////
|
|
|
|
function writeLocked (lockInfo, cb, args) {
|
|
var timeout = lockInfo.timeout;
|
|
if (timeout === undefined) {
|
|
timeout = 60;
|
|
}
|
|
|
|
var ttl = lockInfo.ttl;
|
|
if (ttl === undefined) {
|
|
ttl = 120;
|
|
}
|
|
if (require('internal').coverage || require('internal').valgrind) {
|
|
ttl *= 10;
|
|
timeout *= 10;
|
|
}
|
|
|
|
global.ArangoAgency.lockWrite(lockInfo.part, ttl, timeout);
|
|
|
|
try {
|
|
cb.apply(null, args);
|
|
global.ArangoAgency.increaseVersion(lockInfo.part + '/Version');
|
|
|
|
let version = global.ArangoAgency.get(lockInfo.part + '/Version');
|
|
versions[lockInfo.part.toLowerCase()] = version.arango[lockInfo.part].Version;
|
|
|
|
global.ArangoAgency.unlockWrite(lockInfo.part, timeout);
|
|
} catch (err) {
|
|
global.ArangoAgency.unlockWrite(lockInfo.part, timeout);
|
|
throw err;
|
|
}
|
|
}
|
|
|
|
try {
|
|
versions.success = handleChanges(plan, current, writeLocked);
|
|
|
|
console.debug('plan change handling successful');
|
|
} catch (err) {
|
|
console.error('error details: %s', JSON.stringify(err));
|
|
console.error('error stack: %s', err.stack);
|
|
console.error('plan change handling failed');
|
|
versions.success = false;
|
|
}
|
|
return versions;
|
|
};
|
|
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
// / @brief coordinatorId
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
|
|
var coordinatorId = function () {
|
|
if (!isCoordinator()) {
|
|
console.error('not a coordinator');
|
|
}
|
|
return global.ArangoServerState.id();
|
|
};
|
|
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
// / @brief bootstrap db servers
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
|
|
var bootstrapDbServers = function (isRelaunch) {
|
|
global.ArangoClusterInfo.reloadDBServers();
|
|
|
|
var dbServers = global.ArangoClusterInfo.getDBServers();
|
|
var ops = [];
|
|
var i;
|
|
|
|
var options = {
|
|
coordTransactionID: global.ArangoClusterComm.getId(),
|
|
timeout: 90
|
|
};
|
|
|
|
for (i = 0; i < dbServers.length; ++i) {
|
|
var server = dbServers[i];
|
|
|
|
var op = global.ArangoClusterComm.asyncRequest(
|
|
'POST',
|
|
'server:' + server,
|
|
'_system',
|
|
'/_admin/cluster/bootstrapDbServer',
|
|
'{"isRelaunch": ' + (isRelaunch ? 'true' : 'false') + '}',
|
|
{},
|
|
options);
|
|
|
|
ops.push(op);
|
|
}
|
|
|
|
var result = true;
|
|
|
|
for (i = 0; i < ops.length; ++i) {
|
|
var r = global.ArangoClusterComm.wait(ops[i]);
|
|
|
|
if (r.status === 'RECEIVED') {
|
|
console.info('bootstraped DB server %s', dbServers[i]);
|
|
} else if (r.status === 'TIMEOUT') {
|
|
console.error('cannot bootstrap DB server %s: operation timed out', dbServers[i]);
|
|
result = false;
|
|
} else {
|
|
console.error('cannot bootstrap DB server %s: %s', dbServers[i], JSON.stringify(r));
|
|
result = false;
|
|
}
|
|
}
|
|
|
|
return result;
|
|
};
|
|
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
// / @brief shard distribution
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
|
|
function format (x) {
|
|
var r = {};
|
|
var keys = Object.keys(x);
|
|
for (var i = 0; i < keys.length; ++i) {
|
|
var y = x[keys[i]];
|
|
r[keys[i]] = { leader: y[0], followers: y.slice(1) };
|
|
}
|
|
return r;
|
|
}
|
|
|
|
function shardDistribution () {
|
|
var db = require('internal').db;
|
|
var dbName = db._name();
|
|
var colls = db._collections();
|
|
var result = {};
|
|
for (var i = 0; i < colls.length; ++i) {
|
|
var collName = colls[i].name();
|
|
var collInfo = global.ArangoClusterInfo.getCollectionInfo(dbName,
|
|
collName);
|
|
var shards = collInfo.shards;
|
|
var collInfoCurrent = {};
|
|
var shardNames = Object.keys(shards);
|
|
for (var j = 0; j < shardNames.length; ++j) {
|
|
collInfoCurrent[shardNames[j]] =
|
|
global.ArangoClusterInfo.getCollectionInfoCurrent(
|
|
dbName, collName, shardNames[j]).servers;
|
|
}
|
|
result[collName] = {Plan: format(collInfo.shards),
|
|
Current: format(collInfoCurrent)};
|
|
}
|
|
|
|
return {
|
|
results: result
|
|
};
|
|
}
|
|
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
// / @brief move shard
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
|
|
function moveShard (info) {
|
|
var isLeader;
|
|
var collInfo;
|
|
try {
|
|
collInfo = global.ArangoClusterInfo.getCollectionInfo(info.database,
|
|
info.collection);
|
|
var shards = collInfo.shards;
|
|
var shard = shards[info.shard];
|
|
var pos = shard.indexOf(info.fromServer);
|
|
if (pos === -1) {
|
|
throw 'Banana';
|
|
} else if (pos === 0) {
|
|
isLeader = true;
|
|
} else {
|
|
isLeader = false;
|
|
}
|
|
} catch (e2) {
|
|
return 'Combination of database, collection, shard and fromServer does not make sense.';
|
|
}
|
|
|
|
var id;
|
|
try {
|
|
id = global.ArangoClusterInfo.uniqid();
|
|
var todo = { 'type': 'moveShard',
|
|
'database': info.database,
|
|
'collection': collInfo.id,
|
|
'shard': info.shard,
|
|
'fromServer': info.fromServer,
|
|
'toServer': info.toServer,
|
|
'jobId': id,
|
|
'timeCreated': (new Date()).toISOString(),
|
|
'creator': ArangoServerState.id() };
|
|
global.ArangoAgency.set('Target/ToDo/' + id, todo);
|
|
} catch (e1) {
|
|
return {error: true, errorMessage: 'Cannot write to agency.'};
|
|
}
|
|
|
|
return {error: false, id: id};
|
|
}
|
|
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
// / @brief rebalance shards
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
|
|
function rebalanceShards () {
|
|
var dbServers = global.ArangoClusterInfo.getDBServers();
|
|
var dbTab = {};
|
|
var i, j, k, l;
|
|
for (i = 0; i < dbServers.length; ++i) {
|
|
dbTab[dbServers[i]] = [];
|
|
}
|
|
var shardMap = {};
|
|
|
|
// First count and collect:
|
|
var db = require('internal').db;
|
|
var databases = db._databases();
|
|
for (i = 0; i < databases.length; ++i) {
|
|
db._useDatabase(databases[i]);
|
|
try {
|
|
var colls = db._collections();
|
|
for (j = 0; j < colls.length; ++j) {
|
|
var collName = colls[j].name();
|
|
if (collName.substr(0, 1) === '_') {
|
|
continue;
|
|
}
|
|
var collInfo = global.ArangoClusterInfo.getCollectionInfo(
|
|
databases[i], collName);
|
|
var shardNames = Object.keys(collInfo.shards);
|
|
for (k = 0; k < shardNames.length; k++) {
|
|
var shardName = shardNames[k];
|
|
shardMap[shardName] = { database: databases[i], collection: collName,
|
|
servers: collInfo.shards[shardName],
|
|
weight: 1 };
|
|
dbTab[collInfo.shards[shardName][0]].push(
|
|
{ shard: shardName, leader: true,
|
|
weight: shardMap[shardName].weight });
|
|
for (l = 1; l < collInfo.shards[shardName].length; ++l) {
|
|
dbTab[collInfo.shards[shardName][l]].push(
|
|
{ shard: shardName, leader: false,
|
|
weight: shardMap[shardName].weight });
|
|
}
|
|
}
|
|
}
|
|
} finally {
|
|
db._useDatabase('_system');
|
|
}
|
|
}
|
|
|
|
console.info("Rebalancing shards");
|
|
console.info(shardMap);
|
|
console.info(dbTab);
|
|
|
|
// Compute total weight for each DBServer:
|
|
var totalWeight = [];
|
|
for (i = 0; i < dbServers.length; ++i) {
|
|
totalWeight.push({'server': dbServers[i],
|
|
'weight': _.reduce(dbTab[dbServers[i]],
|
|
(sum, x) => sum + x.weight, 0)});
|
|
}
|
|
totalWeight = _.sortBy(totalWeight, x => x.weight);
|
|
|
|
var shardList = Object.keys(shardMap);
|
|
var countMoved = 0;
|
|
|
|
for (i = 0; i < shardList.length; i++) {
|
|
var last = totalWeight.length - 1;
|
|
var fullest = totalWeight[last].server;
|
|
var emptiest = totalWeight[0].server;
|
|
var weightDiff = totalWeight[last].weight - totalWeight[0].weight;
|
|
if (weightDiff < 1.0) {
|
|
console.log('rebalanceShards: cluster is balanced');
|
|
return true;
|
|
}
|
|
var shard = shardList[i];
|
|
console.log('rebalanceShards: considering shard', shard,
|
|
'totalWeight=', totalWeight);
|
|
if (shardMap[shard].servers.indexOf(fullest) >= 0 &&
|
|
shardMap[shard].servers.indexOf(emptiest) === -1 &&
|
|
shardMap[shard].weight < 0.9 * weightDiff) {
|
|
var shardInfo = shardMap[shard];
|
|
var todo = { database: shardInfo.database,
|
|
collection: shardInfo.collection,
|
|
shard: shard,
|
|
fromServer: fullest,
|
|
toServer: emptiest };
|
|
var msg = moveShard(todo);
|
|
if (msg === '') {
|
|
console.info('rebalanceShards: moveShard(', todo, ')');
|
|
totalWeight[last].weight -= shardInfo.weight;
|
|
totalWeight[0].weight += shardInfo.weight;
|
|
totalWeight = _.sortBy(totalWeight, x => x.weight);
|
|
countMoved += 1;
|
|
if (countMoved >= 10) {
|
|
break;
|
|
}
|
|
} else {
|
|
console.error('rebalanceShards: moveShard(', todo, ') produced:', msg);
|
|
}
|
|
}
|
|
}
|
|
if (countMoved === 0) {
|
|
console.log('rebalanceShards: no sensible moves found');
|
|
return true;
|
|
}
|
|
console.log('rebalanceShards: scheduled', countMoved, ' shard moves.');
|
|
return true;
|
|
}
|
|
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
// / @brief supervision state
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
|
|
function supervisionState () {
|
|
try {
|
|
var result = global.ArangoAgency.get('Target');
|
|
result = result.arango.Target;
|
|
var proj = { ToDo: result.ToDo, Pending: result.Pending,
|
|
Failed: result.Failed, Finished: result.Finished,
|
|
error: false };
|
|
return proj;
|
|
} catch (err) {
|
|
return { error: true, errorMsg: 'could not read /Target in agency',
|
|
exception: err };
|
|
}
|
|
}
|
|
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
// / @brief wait for synchronous replication to settle
|
|
// //////////////////////////////////////////////////////////////////////////////
|
|
|
|
function waitForSyncReplOneCollection (dbName, collName) {
|
|
console.debug('waitForSyncRepl:', dbName, collName);
|
|
var count = 60;
|
|
while (--count > 0) {
|
|
var cinfo = global.ArangoClusterInfo.getCollectionInfo(dbName, collName);
|
|
var shards = Object.keys(cinfo.shards);
|
|
var ccinfo = shards.map(function (s) {
|
|
return global.ArangoClusterInfo.getCollectionInfoCurrent(dbName,
|
|
collName, s).servers;
|
|
});
|
|
console.debug('waitForSyncRepl', dbName, collName, shards, cinfo.shards, ccinfo);
|
|
var ok = true;
|
|
for (var i = 0; i < shards.length; ++i) {
|
|
if (cinfo.shards[shards[i]].length !== ccinfo[i].length) {
|
|
ok = false;
|
|
}
|
|
}
|
|
if (ok) {
|
|
console.debug('waitForSyncRepl: OK:', dbName, collName, shards);
|
|
return true;
|
|
}
|
|
require('internal').wait(1);
|
|
}
|
|
console.warn('waitForSyncRepl:', dbName, collName, ': BAD');
|
|
return false;
|
|
}
|
|
|
|
function waitForSyncRepl (dbName, collList) {
|
|
if (!isCoordinator()) {
|
|
return true;
|
|
}
|
|
var ok = true;
|
|
for (var i = 0; i < collList.length; ++i) {
|
|
ok = waitForSyncReplOneCollection(dbName, collList[i].name()) && ok;
|
|
}
|
|
return ok;
|
|
}
|
|
|
|
exports.bootstrapDbServers = bootstrapDbServers;
|
|
exports.coordinatorId = coordinatorId;
|
|
exports.handlePlanChange = handlePlanChange;
|
|
exports.isCluster = isCluster;
|
|
exports.isCoordinator = isCoordinator;
|
|
exports.isCoordinatorRequest = isCoordinatorRequest;
|
|
exports.role = role;
|
|
exports.shardList = shardList;
|
|
exports.status = status;
|
|
exports.wait = waitForDistributedResponse;
|
|
exports.endpointToURL = endpointToURL;
|
|
exports.synchronizeOneShard = synchronizeOneShard;
|
|
exports.shardDistribution = shardDistribution;
|
|
exports.rebalanceShards = rebalanceShards;
|
|
exports.moveShard = moveShard;
|
|
exports.supervisionState = supervisionState;
|
|
exports.waitForSyncRepl = waitForSyncRepl;
|