1
0
Fork 0
arangodb/js/server/modules/org/arangodb/cluster.js

987 lines
32 KiB
JavaScript

/*jslint indent: 2, nomen: true, maxlen: 120, sloppy: true, vars: true, white: true, plusplus: true */
/*global ArangoAgency, ArangoClusterComm, ArangoClusterInfo, ArangoServerState, require, exports */
////////////////////////////////////////////////////////////////////////////////
/// @brief JavaScript cluster functionality
///
/// @file
///
/// DISCLAIMER
///
/// Copyright 2012 triagens GmbH, Cologne, Germany
///
/// Licensed under the Apache License, Version 2.0 (the "License");
/// you may not use this file except in compliance with the License.
/// You may obtain a copy of the License at
///
/// http://www.apache.org/licenses/LICENSE-2.0
///
/// Unless required by applicable law or agreed to in writing, software
/// distributed under the License is distributed on an "AS IS" BASIS,
/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
/// See the License for the specific language governing permissions and
/// limitations under the License.
///
/// Copyright holder is triAGENS GmbH, Cologne, Germany
///
/// @author Jan Steemann
/// @author Copyright 2012, triAGENS GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////
var console = require("console");
var arangodb = require("org/arangodb");
var ArangoCollection = arangodb.ArangoCollection;
var ArangoError = arangodb.ArangoError;
var PortFinder = require("org/arangodb/cluster/planner").PortFinder;
var Planner = require("org/arangodb/cluster/planner").Planner;
var Kickstarter = require("org/arangodb/cluster/kickstarter").Kickstarter;
var internal = require("internal");
////////////////////////////////////////////////////////////////////////////////
/// @brief get values from Plan or Current by a prefix
////////////////////////////////////////////////////////////////////////////////
function getByPrefix (values, prefix) {
var result = { };
var a;
var n = prefix.length;
for (a in values) {
if (values.hasOwnProperty(a)) {
if (a.substr(0, n) === prefix) {
result[a.substr(n)] = values[a];
}
}
}
return result;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief get values from Plan or Current by a prefix
////////////////////////////////////////////////////////////////////////////////
function getByPrefix3d (values, prefix) {
var result = { };
var a;
var n = prefix.length;
for (a in values) {
if (values.hasOwnProperty(a)) {
if (a.substr(0, n) === prefix) {
var key = a.substr(n);
var parts = key.split('/');
if (parts.length >= 2) {
if (! result.hasOwnProperty(parts[0])) {
result[parts[0]] = { };
}
result[parts[0]][parts[1]] = values[a];
}
}
}
}
return result;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief get values from Plan or Current by a prefix
////////////////////////////////////////////////////////////////////////////////
function getByPrefix4d (values, prefix) {
var result = { };
var a;
var n = prefix.length;
for (a in values) {
if (values.hasOwnProperty(a)) {
if (a.substr(0, n) === prefix) {
var key = a.substr(n);
var parts = key.split('/');
if (parts.length >= 3) {
if (! result.hasOwnProperty(parts[0])) {
result[parts[0]] = { };
}
if (! result[parts[0]].hasOwnProperty(parts[1])) {
result[parts[0]][parts[1]] = { };
}
result[parts[0]][parts[1]][parts[2]] = values[a];
}
}
}
}
return result;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief return a shardId => server map
////////////////////////////////////////////////////////////////////////////////
function getShardMap (plannedCollections) {
var shardMap = { };
var database;
for (database in plannedCollections) {
if (plannedCollections.hasOwnProperty(database)) {
var collections = plannedCollections[database];
var collection;
for (collection in collections) {
if (collections.hasOwnProperty(collection)) {
var shards = collections[collection].shards;
var shard;
for (shard in shards) {
if (shards.hasOwnProperty(shard)) {
shardMap[shard] = shards[shard];
}
}
}
}
}
}
return shardMap;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief return the indexes of a collection as a map
////////////////////////////////////////////////////////////////////////////////
function getIndexMap (shard) {
var indexes = { }, i;
var idx = arangodb.db._collection(shard).getIndexes();
for (i = 0; i < idx.length; ++i) {
// fetch id without collection name
var id = idx[i].id.replace(/^[a-zA-Z0-9_\-]*?\/([0-9]+)$/, '$1');
idx[i].id = id;
indexes[id] = idx[i];
}
return indexes;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief execute an action under a write-lock
////////////////////////////////////////////////////////////////////////////////
function writeLocked (lockInfo, cb, args) {
var timeout = lockInfo.timeout;
if (timeout === undefined) {
timeout = 5;
}
var ttl = lockInfo.ttl;
if (ttl === undefined) {
ttl = 10;
}
ArangoAgency.lockWrite(lockInfo.part, ttl, timeout);
try {
cb.apply(this, args);
ArangoAgency.increaseVersion(lockInfo.part + "/Version");
ArangoAgency.unlockWrite(lockInfo.part, timeout);
}
catch (err) {
ArangoAgency.unlockWrite(lockInfo.part, timeout);
throw err;
}
}
////////////////////////////////////////////////////////////////////////////////
/// @brief return a hash with the local databases
////////////////////////////////////////////////////////////////////////////////
function getLocalDatabases () {
var result = { };
var db = require("internal").db;
db._listDatabases().forEach(function (database) {
result[database] = { name: database };
});
return result;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief return a hash with the local collections
////////////////////////////////////////////////////////////////////////////////
function getLocalCollections () {
var result = { };
var db = require("internal").db;
db._collections().forEach(function (collection) {
var name = collection.name();
if (name.substr(0, 1) !== '_') {
var data = {
id: collection._id,
name: name,
type: collection.type(),
status: collection.status(),
planId: collection.planId()
};
// merge properties
var properties = collection.properties();
var p;
for (p in properties) {
if (properties.hasOwnProperty(p)) {
data[p] = properties[p];
}
}
result[name] = data;
}
});
return result;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief create databases if they exist in the plan but not locally
////////////////////////////////////////////////////////////////////////////////
function createLocalDatabases (plannedDatabases) {
var ourselves = ArangoServerState.id();
var createDatabaseAgency = function (payload) {
ArangoAgency.set("Current/Databases/" + payload.name + "/" + ourselves,
payload);
};
var db = require("internal").db;
db._useDatabase("_system");
var localDatabases = getLocalDatabases();
var name;
// check which databases need to be created locally
for (name in plannedDatabases) {
if (plannedDatabases.hasOwnProperty(name)) {
var payload = plannedDatabases[name];
payload.error = false;
payload.errorNum = 0;
payload.errorMessage = "no error";
if (! localDatabases.hasOwnProperty(name)) {
// must create database
// TODO: handle options and user information
console.info("creating local database '%s'", payload.name);
try {
db._createDatabase(payload.name);
payload.error = false;
payload.errorNum = 0;
payload.errorMessage = "no error";
}
catch (err) {
payload.error = true;
payload.errorNum = err.errorNum;
payload.errorMessage = err.errorMessage;
}
}
writeLocked({ part: "Current" },
createDatabaseAgency,
[ payload ]);
}
}
}
////////////////////////////////////////////////////////////////////////////////
/// @brief drop databases if they do exist locally but not in the plan
////////////////////////////////////////////////////////////////////////////////
function dropLocalDatabases (plannedDatabases) {
var ourselves = ArangoServerState.id();
var dropDatabaseAgency = function (payload) {
try {
ArangoAgency.remove("Current/Databases/" + payload.name + "/" + ourselves);
}
catch (err) {
// ignore errors
}
};
var db = require("internal").db;
db._useDatabase("_system");
var localDatabases = getLocalDatabases();
var name;
// check which databases need to be deleted locally
for (name in localDatabases) {
if (localDatabases.hasOwnProperty(name)) {
if (! plannedDatabases.hasOwnProperty(name) && name.substr(0, 1) !== '_') {
// must drop database
console.info("dropping local database '%s'", name);
db._dropDatabase(name);
writeLocked({ part: "Current" },
dropDatabaseAgency,
[ { name: name } ]);
}
}
}
}
////////////////////////////////////////////////////////////////////////////////
/// @brief clean up what's in Current/Databases for ourselves
////////////////////////////////////////////////////////////////////////////////
function cleanupCurrentDatabases () {
var ourselves = ArangoServerState.id();
var dropDatabaseAgency = function (payload) {
try {
ArangoAgency.remove("Current/Databases/" + payload.name + "/" + ourselves);
}
catch (err) {
// ignore errors
}
};
var db = require("internal").db;
db._useDatabase("_system");
var all = ArangoAgency.get("Current/Databases", true);
var currentDatabases = getByPrefix3d(all, "Current/Databases/");
var localDatabases = getLocalDatabases();
var name;
for (name in currentDatabases) {
if (currentDatabases.hasOwnProperty(name) && name.substr(0, 1) !== '_') {
if (! localDatabases.hasOwnProperty(name)) {
// we found a database we don't have locally
if (currentDatabases[name].hasOwnProperty(ourselves)) {
// we are entered for a database that we don't have locally
console.info("cleaning up entry for unknown database '%s'", name);
writeLocked({ part: "Current" },
dropDatabaseAgency,
[ { name: name } ]);
}
}
}
}
}
////////////////////////////////////////////////////////////////////////////////
/// @brief handle database changes
////////////////////////////////////////////////////////////////////////////////
function handleDatabaseChanges (plan, current) {
var plannedDatabases = getByPrefix(plan, "Plan/Databases/");
createLocalDatabases(plannedDatabases);
dropLocalDatabases(plannedDatabases);
cleanupCurrentDatabases();
}
////////////////////////////////////////////////////////////////////////////////
/// @brief create collections if they exist in the plan but not locally
////////////////////////////////////////////////////////////////////////////////
function createLocalCollections (plannedCollections) {
var ourselves = ArangoServerState.id();
var createCollectionAgency = function (database, shard, payload) {
ArangoAgency.set("Current/Collections/" + database + "/" + payload.id + "/" + shard,
payload);
};
var db = require("internal").db;
db._useDatabase("_system");
var localDatabases = getLocalDatabases();
var database;
var i;
// iterate over all matching databases
for (database in plannedCollections) {
if (plannedCollections.hasOwnProperty(database)) {
if (localDatabases.hasOwnProperty(database)) {
// save old database name
var previousDatabase = db._name();
// switch into other database
db._useDatabase(database);
try {
// iterate over collections of database
var localCollections = getLocalCollections();
var collections = plannedCollections[database];
var collection;
// diff the collections
for (collection in collections) {
if (collections.hasOwnProperty(collection)) {
var payload = collections[collection];
var shards = payload.shards;
var shard;
for (shard in shards) {
if (shards.hasOwnProperty(shard)) {
if (shards[shard] === ourselves) {
// found a shard we are responsible for
if (! localCollections.hasOwnProperty(shard)) {
// must create this shard
payload.planId = payload.id;
console.info("creating local shard '%s/%s' for central '%s/%s'",
database,
shard,
database,
payload.id);
try {
if (payload.type === ArangoCollection.TYPE_EDGE) {
db._createEdgeCollection(shard, payload);
}
else {
db._create(shard, payload);
}
payload.error = false;
payload.errorNum = 0;
payload.errorMessage = "no error";
}
catch (err2) {
payload.error = true;
payload.errorNum = err2.errorNum;
payload.errorMessage = err2.errorMessage;
console.error("creating local shard '%s/%s' for central '%s/%s' failed: %s",
database,
shard,
database,
payload.id,
JSON.stringify(err2));
}
payload.DBServer = ourselves;
writeLocked({ part: "Current" },
createCollectionAgency,
[ database, shard, payload ]);
}
else {
if (localCollections[shard].status !== payload.status) {
console.info("detected status change for local shard '%s/%s'",
database,
shard);
if (payload.status === ArangoCollection.STATUS_UNLOADED) {
console.info("unloading local shard '%s/%s'",
database,
shard);
db._collection(shard).unload();
}
else if (payload.status === ArangoCollection.STATUS_LOADED) {
console.info("loading local shard '%s/%s'",
database,
shard);
db._collection(shard).load();
}
payload.error = false;
payload.errorNum = 0;
payload.errorMessage = "no error";
payload.DBServer = ourselves;
writeLocked({ part: "Current" },
createCollectionAgency,
[ database, shard, payload ]);
}
// collection exists, now compare collection properties
var properties = { };
var cmp = [ "journalSize", "waitForSync", "doCompact" ];
for (i = 0; i < cmp.length; ++i) {
var p = cmp[i];
if (localCollections[shard][p] !== payload[p]) {
// property change
properties[p] = payload[p];
}
}
if (Object.keys(properties).length > 0) {
console.info("updating properties for local shard '%s/%s'",
database,
shard);
try {
db._collection(shard).properties(properties);
payload.error = false;
payload.errorNum = 0;
payload.errorMessage = "no error";
}
catch (err3) {
payload.error = true;
payload.errorNum = err3.errorNum;
payload.errorMessage = err3.errorMessage;
}
payload.DBServer = ourselves;
writeLocked({ part: "Current" },
createCollectionAgency,
[ database, shard, payload ]);
}
}
var indexes = getIndexMap(shard);
var idx;
var index;
if (payload.hasOwnProperty("indexes")) {
for (i = 0; i < payload.indexes.length; ++i) {
index = payload.indexes[i];
if (index.type !== "primary" && index.type !== "edge" &&
! indexes.hasOwnProperty(index.id)) {
console.info("creating index '%s/%s': %s",
database,
shard,
JSON.stringify(index));
indexes[index.id] = index;
try {
arangodb.db._collection(shard).ensureIndex(index);
indexes[index.id].error = false;
indexes[index.id].errorNum = 0;
indexes[index.id].errorMessage = "";
}
catch (err5) {
indexes[index.id].error = true;
indexes[index.id].errorNum = err5.errorNum;
indexes[index.id].errorMessage = err5.errorMessage;
}
payload.DBServer = ourselves;
writeLocked({ part: "Current" },
createCollectionAgency,
[ database, shard, payload ]);
}
}
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 < payload.indexes.length; ++i) {
if (payload.indexes[i].id === idx) {
found = true;
break;
}
}
if (! found) {
// found an index to delete locally
index = indexes[idx];
console.info("dropping index '%s/%s': %s",
database,
shard,
JSON.stringify(index));
arangodb.db._collection(shard).dropIndex(index);
delete indexes[idx];
payload.indexes.splice(i, i);
payload.DBServer = ourselves;
writeLocked({ part: "Current" },
createCollectionAgency,
[ database, shard, payload ]);
}
}
}
}
}
}
}
}
}
}
}
catch (err) {
// always return to previous database
db._useDatabase(previousDatabase);
throw err;
}
}
}
}
}
////////////////////////////////////////////////////////////////////////////////
/// @brief drop collections if they exist locally but not in the plan
////////////////////////////////////////////////////////////////////////////////
function dropLocalCollections (plannedCollections) {
var ourselves = ArangoServerState.id();
var dropCollectionAgency = function (database, shardID, id) {
try {
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);
// save old database name
var previousDatabase = db._name();
// 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] !== ourselves);
if (remove) {
console.info("dropping local shard '%s/%s' of '%s/%s",
database,
collection,
database,
collections[collection].planId);
db._drop(collection);
writeLocked({ part: "Current" },
dropCollectionAgency,
[ database, collection, collections[collection].planId ]);
}
}
}
}
catch (err) {
db._useDatabase(previousDatabase);
throw err;
}
}
}
}
////////////////////////////////////////////////////////////////////////////////
/// @brief clean up what's in Current/Collections for ourselves
////////////////////////////////////////////////////////////////////////////////
function cleanupCurrentCollections (plannedCollections) {
var ourselves = ArangoServerState.id();
var dropCollectionAgency = function (database, collection, shardID) {
try {
ArangoAgency.remove("Current/Collections/" + database + "/" + collection + "/" + shardID);
}
catch (err) {
// ignore errors
}
};
var db = require("internal").db;
db._useDatabase("_system");
var all = ArangoAgency.get("Current/Collections", true);
var currentCollections = getByPrefix4d(all, "Current/Collections/");
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 (shards[shard].DBServer === ourselves &&
(! shardMap.hasOwnProperty(shard) ||
shardMap[shard] !== ourselves)) {
// found a shard we are entered for but that we don't have locally
console.info("cleaning up entry for unknown shard '%s' of '%s/%s",
shard,
database,
collection);
writeLocked({ part: "Current" },
dropCollectionAgency,
[ database, collection, shard ]);
}
}
}
}
}
}
}
}
////////////////////////////////////////////////////////////////////////////////
/// @brief handle collection changes
////////////////////////////////////////////////////////////////////////////////
function handleCollectionChanges (plan, current) {
var plannedCollections = getByPrefix3d(plan, "Plan/Collections/");
createLocalCollections(plannedCollections);
dropLocalCollections(plannedCollections);
cleanupCurrentCollections(plannedCollections);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief change handling trampoline function
////////////////////////////////////////////////////////////////////////////////
function handleChanges (plan, current) {
handleDatabaseChanges(plan, current);
handleCollectionChanges(plan, current);
}
////////////////////////////////////////////////////////////////////////////////
/// @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 = 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 wait = function (data, shards) {
var received = [ ];
while (received.length < shards.length) {
var result = ArangoClusterComm.wait(data);
var status = result.status;
if (status === "ERROR") {
raiseError(arangodb.errors.ERROR_INTERNAL.code,
"received an error from a DB server");
}
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,
"received an error from a DB server");
}
raiseError(body.errorNum,
body.errorMessage);
}
}
}
else {
// something else... wait without GC
require("internal").wait(0.1, false);
}
}
return received;
};
////////////////////////////////////////////////////////////////////////////////
/// @brief whether or not clustering is enabled
////////////////////////////////////////////////////////////////////////////////
var isCluster = function () {
return (typeof ArangoServerState !== "undefined" &&
ArangoServerState.initialised());
};
////////////////////////////////////////////////////////////////////////////////
/// @brief whether or not we are a coordinator
////////////////////////////////////////////////////////////////////////////////
var isCoordinator = function () {
if (! isCluster()) {
return false;
}
return ArangoServerState.isCoordinator();
};
////////////////////////////////////////////////////////////////////////////////
/// @brief role
////////////////////////////////////////////////////////////////////////////////
var role = function () {
if (! isCluster()) {
return undefined;
}
return ArangoServerState.role();
};
////////////////////////////////////////////////////////////////////////////////
/// @brief status
////////////////////////////////////////////////////////////////////////////////
var status = function () {
if (! isCluster()) {
return undefined;
}
return 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 () {
if (! isCluster() || isCoordinator()) {
return;
}
try {
var plan = ArangoAgency.get("Plan", true);
var current = ArangoAgency.get("Current", true);
handleChanges(plan, current);
console.info("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");
}
};
////////////////////////////////////////////////////////////////////////////////
/// @brief dispatcherDisabled
////////////////////////////////////////////////////////////////////////////////
var dispatcherDisabled = function () {
return internal.DISABLE_CLUSTER_DISPATCHER;
}
// -----------------------------------------------------------------------------
// --SECTION-- MODULE EXPORTS
// -----------------------------------------------------------------------------
exports.dispatcherDisabled = dispatcherDisabled;
exports.handlePlanChange = handlePlanChange;
exports.isCluster = isCluster;
exports.isCoordinator = isCoordinator;
exports.isCoordinatorRequest = isCoordinatorRequest;
exports.role = role;
exports.shardList = shardList;
exports.status = status;
exports.wait = wait;
exports.Kickstarter = Kickstarter;
exports.Planner = Planner;
exports.PortFinder = PortFinder;
// -----------------------------------------------------------------------------
// --SECTION-- END-OF-FILE
// -----------------------------------------------------------------------------
// Local Variables:
// mode: outline-minor
// outline-regexp: "\\(/// @brief\\|/// @addtogroup\\|// --SECTION--\\|/// @page\\|/// @\\}\\)"
// End: