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arangodb/arangod/Agency/RestAgencyHandler.cpp

500 lines
16 KiB
C++

////////////////////////////////////////////////////////////////////////////////
/// DISCLAIMER
///
/// Copyright 2014-2016 ArangoDB GmbH, Cologne, Germany
/// Copyright 2004-2014 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 ArangoDB GmbH, Cologne, Germany
///
/// @author Kaveh Vahedipour
////////////////////////////////////////////////////////////////////////////////
#include "RestAgencyHandler.h"
#include <thread>
#include <velocypack/Builder.h>
#include <velocypack/velocypack-aliases.h>
#include "Agency/Agent.h"
#include "Basics/StaticStrings.h"
#include "Logger/Logger.h"
#include "Rest/HttpRequest.h"
#include "Rest/Version.h"
using namespace arangodb;
using namespace arangodb::basics;
using namespace arangodb::rest;
using namespace arangodb::consensus;
////////////////////////////////////////////////////////////////////////////////
/// @brief ArangoDB server
////////////////////////////////////////////////////////////////////////////////
RestAgencyHandler::RestAgencyHandler(GeneralRequest* request,
GeneralResponse* response, Agent* agent)
: RestBaseHandler(request, response), _agent(agent) {}
bool RestAgencyHandler::isDirect() const { return false; }
inline RestStatus RestAgencyHandler::reportErrorEmptyRequest() {
LOG_TOPIC(WARN, Logger::AGENCY)
<< "Empty request to public agency interface.";
generateError(rest::ResponseCode::NOT_FOUND, 404);
return RestStatus::DONE;
}
inline RestStatus RestAgencyHandler::reportTooManySuffices() {
LOG_TOPIC(WARN, Logger::AGENCY)
<< "Too many suffixes. Agency public interface takes one path.";
generateError(rest::ResponseCode::NOT_FOUND, 404);
return RestStatus::DONE;
}
inline RestStatus RestAgencyHandler::reportUnknownMethod() {
LOG_TOPIC(WARN, Logger::AGENCY) << "Public REST interface has no method "
<< _request->suffixes()[0];
generateError(rest::ResponseCode::NOT_FOUND, 405);
return RestStatus::DONE;
}
void RestAgencyHandler::redirectRequest(std::string const& leaderId) {
try {
std::string url = Endpoint::uriForm(_agent->config().poolAt(leaderId)) +
_request->requestPath();
_response->setResponseCode(rest::ResponseCode::TEMPORARY_REDIRECT);
_response->setHeaderNC(StaticStrings::Location, url);
LOG_TOPIC(DEBUG, Logger::AGENCY) << "Sending 307 redirect to " << url;
} catch (std::exception const& e) {
LOG_TOPIC(WARN, Logger::AGENCY) << e.what() << " " << __FILE__ << ":"
<< __LINE__;
generateError(rest::ResponseCode::SERVER_ERROR, TRI_ERROR_INTERNAL,
e.what());
}
}
RestStatus RestAgencyHandler::handleStores() {
if (_request->requestType() == rest::RequestType::GET) {
Builder body;
body.openObject();
body.add("spearhead", VPackValue(VPackValueType::Array));
_agent->spearhead().dumpToBuilder(body);
body.close();
body.add("read_db", VPackValue(VPackValueType::Array));
_agent->readDB().dumpToBuilder(body);
body.close();
body.close();
generateResult(rest::ResponseCode::OK, body.slice());
} else {
generateError(rest::ResponseCode::BAD, 400);
}
return RestStatus::DONE;
}
RestStatus RestAgencyHandler::handleWrite() {
if (_request->requestType() != rest::RequestType::POST) {
generateError(rest::ResponseCode::METHOD_NOT_ALLOWED, 405);
}
arangodb::velocypack::Options options;
query_t query;
// Convert to velocypack
try {
query = _request->toVelocyPackBuilderPtr(&options);
} catch (std::exception const& e) {
LOG_TOPIC(ERR, Logger::AGENCY)
<< e.what() << " " << __FILE__ << ":" << __LINE__;
Builder body;
body.openObject();
body.add("message", VPackValue(e.what()));
body.close();
generateResult(rest::ResponseCode::BAD, body.slice());
return RestStatus::DONE;
}
// Need Array input
if (!query->slice().isArray()) {
Builder body;
body.openObject();
body.add(
"message", VPackValue("Expecting array of arrays as body for writes"));
body.close();
generateResult(rest::ResponseCode::BAD, body.slice());
return RestStatus::DONE;
}
// Empty request array
if (query->slice().length() == 0) {
Builder body;
body.openObject();
body.add("message", VPackValue("Empty request."));
body.close();
generateResult(rest::ResponseCode::BAD, body.slice());
return RestStatus::DONE;
}
// Leadership established?
auto s = std::chrono::system_clock::now();
std::chrono::duration<double> timeout(_agent->config().minPing());
while (_agent->size() > 1 && _agent->leaderID() == NO_LEADER) {
if ((std::chrono::system_clock::now() - s) > timeout) {
Builder body;
body.openObject();
body.add("message", VPackValue("No leader"));
body.close();
generateResult(rest::ResponseCode::SERVICE_UNAVAILABLE, body.slice());
LOG_TOPIC(DEBUG, Logger::AGENCY) << "We don't know who the leader is";
return RestStatus::DONE;
}
std::this_thread::sleep_for(duration_t(100));
}
// Do write
write_ret_t ret;
try {
ret = _agent->write(query);
} catch (std::exception const& e) {
LOG_TOPIC(DEBUG, Logger::AGENCY) << "Malformed write query " << query;
Builder body;
body.openObject();
body.add("message",
VPackValue(std::string("Malformed write query") + e.what()));
body.close();
generateResult(rest::ResponseCode::BAD, body.slice());
return RestStatus::DONE;
}
// We're leading and handling the request
if (ret.accepted) {
bool found;
std::string call_mode = _request->header("x-arangodb-agency-mode", found);
if (!found) {
call_mode = "waitForCommitted";
}
size_t errors = 0;
Builder body;
body.openObject();
if (call_mode != "noWait") {
// Note success/error
body.add("results", VPackValue(VPackValueType::Array));
for (auto const& index : ret.indices) {
body.add(VPackValue(index));
if (index == 0) {
errors++;
}
}
body.close();
// Wait for commit of highest except if it is 0?
if (!ret.indices.empty() && call_mode == "waitForCommitted") {
arangodb::consensus::index_t max_index = 0;
try {
max_index =
*std::max_element(ret.indices.begin(), ret.indices.end());
} catch (std::exception const& e) {
LOG_TOPIC(WARN, Logger::AGENCY)
<< e.what() << " " << __FILE__ << ":" << __LINE__;
}
if (max_index > 0) {
_agent->waitFor(max_index);
}
}
}
body.close();
if (errors > 0) { // Some/all requests failed
generateResult(rest::ResponseCode::PRECONDITION_FAILED, body.slice());
} else { // All good
generateResult(rest::ResponseCode::OK, body.slice());
}
} else { // Redirect to leader
if (_agent->leaderID() == NO_LEADER) {
Builder body;
body.openObject();
body.add("message", VPackValue("No leader"));
body.close();
generateResult(rest::ResponseCode::SERVICE_UNAVAILABLE, body.slice());
LOG_TOPIC(DEBUG, Logger::AGENCY) << "We don't know who the leader is";
return RestStatus::DONE;
} else {
TRI_ASSERT(ret.redirect != _agent->id());
redirectRequest(ret.redirect);
}
}
return RestStatus::DONE;
}
RestStatus RestAgencyHandler::handleTransact() {
if (_request->requestType() != rest::RequestType::POST) {
generateError(rest::ResponseCode::METHOD_NOT_ALLOWED, 405);
}
arangodb::velocypack::Options options;
query_t query;
// Convert to velocypack
try {
query = _request->toVelocyPackBuilderPtr(&options);
} catch (std::exception const& e) {
LOG_TOPIC(ERR, Logger::AGENCY)
<< e.what() << " " << __FILE__ << ":" << __LINE__;
Builder body;
body.openObject();
body.add("message", VPackValue(e.what()));
body.close();
generateResult(rest::ResponseCode::BAD, body.slice());
return RestStatus::DONE;
}
// Need Array input
if (!query->slice().isArray()) {
Builder body;
body.openObject();
body.add(
"message", VPackValue("Expecting array of arrays as body for writes"));
body.close();
generateResult(rest::ResponseCode::BAD, body.slice());
return RestStatus::DONE;
}
// Empty request array
if (query->slice().length() == 0) {
Builder body;
body.openObject();
body.add("message", VPackValue("Empty request."));
body.close();
generateResult(rest::ResponseCode::BAD, body.slice());
return RestStatus::DONE;
}
// Leadership established?
auto s = std::chrono::system_clock::now();
std::chrono::duration<double> timeout(_agent->config().minPing());
while (_agent->size() > 1 && _agent->leaderID() == NO_LEADER) {
if ((std::chrono::system_clock::now() - s) > timeout) {
Builder body;
body.openObject();
body.add("message", VPackValue("No leader"));
body.close();
generateResult(rest::ResponseCode::SERVICE_UNAVAILABLE, body.slice());
LOG_TOPIC(DEBUG, Logger::AGENCY) << "We don't know who the leader is";
return RestStatus::DONE;
}
std::this_thread::sleep_for(duration_t(100));
}
// Do write
trans_ret_t ret;
try {
ret = _agent->transact(query);
} catch (std::exception const& e) {
LOG_TOPIC(DEBUG, Logger::AGENCY) << "Malformed write query " << query;
Builder body;
body.openObject();
body.add(
"message", VPackValue(std::string("Malformed write query") + e.what()));
body.close();
generateResult(rest::ResponseCode::BAD, body.slice());
return RestStatus::DONE;
}
// We're leading and handling the request
if (ret.accepted) {
// Wait for commit of highest except if it is 0?
if (ret.maxind > 0) {
_agent->waitFor(ret.maxind);
}
generateResult(
(ret.failed==0) ?
rest::ResponseCode::OK : rest::ResponseCode::PRECONDITION_FAILED,
ret.result->slice());
} else { // Redirect to leader
if (_agent->leaderID() == NO_LEADER) {
Builder body;
body.openObject();
body.add("message", VPackValue("No leader"));
body.close();
generateResult(rest::ResponseCode::SERVICE_UNAVAILABLE, body.slice());
LOG_TOPIC(DEBUG, Logger::AGENCY) << "We don't know who the leader is";
return RestStatus::DONE;
} else {
TRI_ASSERT(ret.redirect != _agent->id());
redirectRequest(ret.redirect);
}
}
return RestStatus::DONE;
}
inline RestStatus RestAgencyHandler::handleRead() {
arangodb::velocypack::Options options;
if (_request->requestType() == rest::RequestType::POST) {
query_t query;
try {
query = _request->toVelocyPackBuilderPtr(&options);
} catch (std::exception const& e) {
LOG_TOPIC(DEBUG, Logger::AGENCY)
<< e.what() << " " << __FILE__ << ":" << __LINE__;
generateError(rest::ResponseCode::BAD, 400);
return RestStatus::DONE;
}
auto s = std::chrono::system_clock::now(); // Leadership established?
std::chrono::duration<double> timeout(_agent->config().minPing());
while (_agent->size() > 1 && _agent->leaderID() == NO_LEADER) {
if ((std::chrono::system_clock::now() - s) > timeout) {
Builder body;
body.openObject();
body.add("message", VPackValue("No leader"));
body.close();
generateResult(rest::ResponseCode::SERVICE_UNAVAILABLE, body.slice());
LOG_TOPIC(DEBUG, Logger::AGENCY) << "We don't know who the leader is";
return RestStatus::DONE;
}
std::this_thread::sleep_for(duration_t(100));
}
read_ret_t ret = _agent->read(query);
if (ret.accepted) { // I am leading
if (ret.success.size() == 1 && !ret.success.at(0)) {
generateResult(rest::ResponseCode::I_AM_A_TEAPOT, ret.result->slice());
} else {
generateResult(rest::ResponseCode::OK, ret.result->slice());
}
} else { // Redirect to leader
if (_agent->leaderID() == NO_LEADER) {
Builder body;
body.openObject();
body.add("message", VPackValue("No leader"));
body.close();
generateResult(rest::ResponseCode::SERVICE_UNAVAILABLE, body.slice());
LOG_TOPIC(DEBUG, Logger::AGENCY) << "We don't know who the leader is";
return RestStatus::DONE;
} else {
TRI_ASSERT(ret.redirect != _agent->id());
redirectRequest(ret.redirect);
}
return RestStatus::DONE;
}
} else {
generateError(rest::ResponseCode::METHOD_NOT_ALLOWED, 405);
return RestStatus::DONE;
}
return RestStatus::DONE;
}
RestStatus RestAgencyHandler::handleConfig() {
if (_request->requestType() == rest::RequestType::POST) {
try {
arangodb::velocypack::Options options;
_agent->updatePeerEndpoint(_request->toVelocyPackBuilderPtr(&options));
} catch (std::exception const& e) {
generateError(
rest::ResponseCode::SERVER_ERROR, TRI_ERROR_INTERNAL, e.what());
return RestStatus::DONE;
}
}
Builder body;
body.add(VPackValue(VPackValueType::Object));
body.add("term", Value(_agent->term()));
body.add("leaderId", Value(_agent->leaderID()));
body.add("lastCommitted", Value(_agent->lastCommitted()));
body.add("lastAcked", _agent->lastAckedAgo()->slice());
body.add("configuration", _agent->config().toBuilder()->slice());
body.close();
generateResult(rest::ResponseCode::OK, body.slice());
return RestStatus::DONE;
}
RestStatus RestAgencyHandler::handleState() {
Builder body;
body.add(VPackValue(VPackValueType::Array));
for (auto const& i : _agent->state().get()) {
body.add(VPackValue(VPackValueType::Object));
body.add("index", VPackValue(i.index));
body.add("term", VPackValue(i.term));
body.add("query", VPackSlice(i.entry->data()));
body.close();
}
body.close();
generateResult(rest::ResponseCode::OK, body.slice());
return RestStatus::DONE;
}
inline RestStatus RestAgencyHandler::reportMethodNotAllowed() {
generateError(rest::ResponseCode::METHOD_NOT_ALLOWED, 405);
return RestStatus::DONE;
}
RestStatus RestAgencyHandler::execute() {
try {
auto const& suffixes = _request->suffixes();
if (suffixes.empty()) { // Empty request
return reportErrorEmptyRequest();
} else if (suffixes.size() > 1) { // path size >= 2
return reportTooManySuffices();
} else {
if (suffixes[0] == "write") {
return handleWrite();
} else if (suffixes[0] == "read") {
return handleRead();
} else if (suffixes[0] == "transact") {
return handleTransact();
} else if (suffixes[0] == "config") {
if (_request->requestType() != rest::RequestType::GET &&
_request->requestType() != rest::RequestType::POST) {
return reportMethodNotAllowed();
}
return handleConfig();
} else if (suffixes[0] == "state") {
if (_request->requestType() != rest::RequestType::GET) {
return reportMethodNotAllowed();
}
return handleState();
} else if (suffixes[0] == "stores") {
return handleStores();
} else {
return reportUnknownMethod();
}
}
} catch (...) {
// Ignore this error
}
return RestStatus::DONE;
}