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arangodb/arangod/Agency/AgencyComm.cpp

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///////////////////////////////////////////////////////////////////////////////
/// 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 Jan Steemann
/// @author Max Neunhoeffer
////////////////////////////////////////////////////////////////////////////////
#include "AgencyComm.h"
#include <velocypack/Iterator.h>
#include <velocypack/Sink.h>
#include <velocypack/velocypack-aliases.h>
#include "Basics/ReadLocker.h"
#include "Basics/StringBuffer.h"
#include "Basics/StringUtils.h"
#include "Basics/VelocyPackHelper.h"
#include "Basics/WriteLocker.h"
#include "Cluster/ClusterComm.h"
#include "Cluster/ServerState.h"
#include "Endpoint/Endpoint.h"
#include "GeneralServer/AuthenticationFeature.h"
#include "Logger/Logger.h"
#include "Random/RandomGenerator.h"
#include "Rest/HttpRequest.h"
#include "Rest/HttpResponse.h"
#include "SimpleHttpClient/GeneralClientConnection.h"
#include "SimpleHttpClient/SimpleHttpClient.h"
#include "SimpleHttpClient/SimpleHttpResult.h"
#include <thread>
#ifdef DEBUG_SYNC_REPLICATION
#include <atomic>
#endif
using namespace arangodb;
using namespace arangodb::application_features;
using namespace arangodb::httpclient;
using namespace arangodb::rest;
#ifdef DEBUG_SYNC_REPLICATION
static std::atomic<uint64_t> debugUniqId(1);
bool AgencyComm::syncReplDebug = false;
#endif
static void addEmptyVPackObject(std::string const& name,
VPackBuilder& builder) {
builder.add(VPackValue(name));
VPackObjectBuilder c(&builder);
}
const std::vector<std::string> AgencyTransaction::TypeUrl(
{ "/read", "/write", "/transact" });
// -----------------------------------------------------------------------------
// --SECTION-- AgencyPrecondition
// -----------------------------------------------------------------------------
AgencyPrecondition::AgencyPrecondition()
: type(AgencyPrecondition::Type::NONE), empty(true) {}
AgencyPrecondition::AgencyPrecondition(std::string const& key, Type t, bool e)
: key(AgencyCommManager::path(key)), type(t), empty(e) {}
AgencyPrecondition::AgencyPrecondition(std::string const& key, Type t,
VPackSlice s)
: key(AgencyCommManager::path(key)), type(t), empty(false), value(s) {}
void AgencyPrecondition::toVelocyPack(VPackBuilder& builder) const {
if (type != AgencyPrecondition::Type::NONE) {
builder.add(VPackValue(key));
{
VPackObjectBuilder preconditionDefinition(&builder);
switch (type) {
case AgencyPrecondition::Type::EMPTY:
builder.add("oldEmpty", VPackValue(empty));
break;
case AgencyPrecondition::Type::VALUE:
builder.add("old", value);
break;
// mop: useless compiler warning :S
case AgencyPrecondition::Type::NONE:
break;
}
}
}
}
void AgencyPrecondition::toGeneralBuilder(VPackBuilder& builder) const {
if (type != AgencyPrecondition::Type::NONE) {
VPackObjectBuilder preconditionDefinition(&builder);
builder.add(VPackValue(key));
{
VPackObjectBuilder preconditionDefinition(&builder);
switch (type) {
case AgencyPrecondition::Type::EMPTY:
builder.add("oldEmpty", VPackValue(empty));
break;
case AgencyPrecondition::Type::VALUE:
builder.add("old", value);
break;
// mop: useless compiler warning :S
case AgencyPrecondition::Type::NONE:
break;
}
}
} else {
VPackObjectBuilder guard(&builder);
}
}
// -----------------------------------------------------------------------------
// --SECTION-- AgencyOperation
// -----------------------------------------------------------------------------
AgencyOperation::AgencyOperation(std::string const& key)
: _key(AgencyCommManager::path(key)), _opType() {
_opType.type = AgencyOperationType::Type::READ;
}
AgencyOperation::AgencyOperation(std::string const& key,
AgencySimpleOperationType opType)
: _key(AgencyCommManager::path(key)), _opType() {
_opType.type = AgencyOperationType::Type::SIMPLE;
_opType.simple = opType;
}
AgencyOperation::AgencyOperation(std::string const& key,
AgencyValueOperationType opType,
VPackSlice value)
: _key(AgencyCommManager::path(key)), _opType(), _value(value) {
_opType.type = AgencyOperationType::Type::VALUE;
_opType.value = opType;
}
AgencyOperationType AgencyOperation::type() const {
return _opType;
}
void AgencyOperation::toVelocyPack(VPackBuilder& builder) const {
builder.add(VPackValue(_key));
{
VPackObjectBuilder valueOperation(&builder);
builder.add("op", VPackValue(_opType.toString()));
if (_opType.type == AgencyOperationType::Type::VALUE) {
if (_opType.value == AgencyValueOperationType::OBSERVE ||
_opType.value == AgencyValueOperationType::UNOBSERVE) {
builder.add("url", _value);
} else {
builder.add("new", _value);
}
if (_ttl > 0) {
builder.add("ttl", VPackValue(_ttl));
}
}
}
}
void AgencyOperation::toGeneralBuilder(VPackBuilder& builder) const {
if (_opType.type == AgencyOperationType::Type::READ) {
builder.add(VPackValue(_key));
} else {
VPackObjectBuilder operation(&builder);
builder.add(VPackValue(_key));
VPackObjectBuilder valueOperation(&builder);
builder.add("op", VPackValue(_opType.toString()));
if (_opType.type == AgencyOperationType::Type::VALUE) {
if (_opType.value == AgencyValueOperationType::OBSERVE ||
_opType.value == AgencyValueOperationType::UNOBSERVE) {
builder.add("url", _value);
} else {
builder.add("new", _value);
}
if (_ttl > 0) {
builder.add("ttl", VPackValue(_ttl));
}
}
}
}
// -----------------------------------------------------------------------------
// --SECTION-- AgencyWriteTransaction
// -----------------------------------------------------------------------------
std::string AgencyWriteTransaction::toJson() const {
VPackBuilder builder;
toVelocyPack(builder);
return builder.toJson();
}
void AgencyWriteTransaction::toVelocyPack(VPackBuilder& builder) const {
VPackArrayBuilder guard(&builder);
{
VPackObjectBuilder guard2(&builder);
for (AgencyOperation const& operation : operations) {
operation.toVelocyPack(builder);
}
}
if (preconditions.size() > 0) {
VPackObjectBuilder guard3(&builder);
for (AgencyPrecondition const& precondition : preconditions) {
precondition.toVelocyPack(builder);
}
}
}
bool AgencyWriteTransaction::validate(AgencyCommResult const& result) const {
return (result.slice().isObject() &&
result.slice().hasKey("results") &&
result.slice().get("results").isArray());
}
// -----------------------------------------------------------------------------
// --SECTION-- AgencyGeneralTransaction
// -----------------------------------------------------------------------------
std::string AgencyGeneralTransaction::toJson() const {
VPackBuilder builder;
toVelocyPack(builder);
return builder.toJson();
}
void AgencyGeneralTransaction::toVelocyPack(VPackBuilder& builder) const {
for (auto const& operation : operations) {
VPackArrayBuilder guard2(&builder);
if (std::get<0>(operation).type().type == AgencyOperationType::Type::READ) {
std::get<0>(operation).toGeneralBuilder(builder);
} else {
std::get<0>(operation).toGeneralBuilder(builder);
std::get<1>(operation).toGeneralBuilder(builder);
}
}
}
void AgencyGeneralTransaction::push_back(
std::pair<AgencyOperation,AgencyPrecondition> const& oper) {
operations.push_back(oper);
}
bool AgencyGeneralTransaction::validate(AgencyCommResult const& result) const {
return (result.slice().isArray() && result.slice().length() == 1);
}
// -----------------------------------------------------------------------------
// --SECTION-- AgencyReadTransaction
// -----------------------------------------------------------------------------
std::string AgencyReadTransaction::toJson() const {
VPackBuilder builder;
toVelocyPack(builder);
return builder.toJson();
}
void AgencyReadTransaction::toVelocyPack(VPackBuilder& builder) const {
VPackArrayBuilder guard2(&builder);
for (std::string const& key : keys) {
builder.add(VPackValue(key));
}
}
bool AgencyReadTransaction::validate(AgencyCommResult const& result) const {
return (result.slice().isArray() && result.slice().length() == 1);
}
// -----------------------------------------------------------------------------
// --SECTION-- AgencyCommResult
// -----------------------------------------------------------------------------
AgencyCommResult::AgencyCommResult()
: _location(),
_message(),
_body(),
_values(),
_statusCode(0),
_connected(false) {}
AgencyCommResult::AgencyCommResult(int code, std::string const& message)
: _location(),
_message(message),
_body(),
_values(),
_statusCode(code),
_connected(false) {}
bool AgencyCommResult::connected() const { return _connected; }
int AgencyCommResult::httpCode() const { return _statusCode; }
int AgencyCommResult::errorCode() const {
try {
std::shared_ptr<VPackBuilder> bodyBuilder =
VPackParser::fromJson(_body);
VPackSlice body = bodyBuilder->slice();
if (!body.isObject()) {
return 0;
}
// get "errorCode" attribute (0 if not exist)
return arangodb::basics::VelocyPackHelper::getNumericValue<int>(
body, "errorCode", 0);
} catch (VPackException const&) {
return 0;
}
}
std::string AgencyCommResult::errorMessage() const {
if (!_message.empty()) {
// return stored message first if set
return _message;
}
if (!_connected) {
return std::string("unable to connect to agency");
}
try {
std::shared_ptr<VPackBuilder> bodyBuilder =
VPackParser::fromJson(_body);
VPackSlice body = bodyBuilder->slice();
if (!body.isObject()) {
return "";
}
// get "message" attribute ("" if not exist)
return arangodb::basics::VelocyPackHelper::getStringValue(body, "message",
"");
} catch (VPackException const& e) {
std::string message("VPackException parsing body (" + _body + "): " +
e.what());
return std::string(message);
}
}
std::string AgencyCommResult::errorDetails() const {
std::string const errorMessage = this->errorMessage();
if (errorMessage.empty()) {
return _message;
}
return _message + " (" + errorMessage + ")";
}
void AgencyCommResult::clear() {
// clear existing values. They free themselves
_values.clear();
_location = "";
_message = "";
_body = "";
_statusCode = 0;
}
VPackSlice AgencyCommResult::slice() const { return _vpack->slice(); }
// -----------------------------------------------------------------------------
// --SECTION-- AgencyCommManager
// -----------------------------------------------------------------------------
std::unique_ptr<AgencyCommManager> AgencyCommManager::MANAGER;
AgencyConnectionOptions
AgencyCommManager::CONNECTION_OPTIONS (15.0, 120.0, 120.0, 100);
void AgencyCommManager::initialize(std::string const& prefix) {
MANAGER.reset(new AgencyCommManager(prefix));
}
void AgencyCommManager::shutdown() { MANAGER.reset(); }
std::string AgencyCommManager::path() {
if (MANAGER == nullptr) {
return "";
}
return MANAGER->_prefix;
}
std::string AgencyCommManager::path(std::string const& p1) {
if (MANAGER == nullptr) {
return "";
}
return MANAGER->_prefix + "/" + StringUtils::trim(p1, "/");
}
std::string AgencyCommManager::path(std::string const& p1,
std::string const& p2) {
if (MANAGER == nullptr) {
return "";
}
return MANAGER->_prefix + "/" + StringUtils::trim(p1, "/") + "/" +
StringUtils::trim(p2, "/");
}
std::string AgencyCommManager::generateStamp() {
time_t tt = time(0);
struct tm tb;
char buffer[21];
TRI_gmtime(tt, &tb);
size_t len = ::strftime(buffer, sizeof(buffer), "%Y-%m-%dT%H:%M:%SZ", &tb);
return std::string(buffer, len);
}
bool AgencyCommManager::start() {
AgencyComm comm;
bool ok = comm.ensureStructureInitialized();
LOG_TOPIC(DEBUG, Logger::AGENCYCOMM)
<< "structures " << (ok ? "are" : "failed to") << " initialize";
return ok;
}
void AgencyCommManager::stop() {
MUTEX_LOCKER(locker, _lock);
for (auto& i : _unusedConnections) {
i.second.clear();
}
_unusedConnections.clear();
}
std::unique_ptr<GeneralClientConnection> AgencyCommManager::acquire(
std::string& endpoint) {
std::unique_ptr<GeneralClientConnection> connection;
MUTEX_LOCKER(locker, _lock);
if (_endpoints.empty()) {
return nullptr;
} else {
if(endpoint.empty()) {
endpoint = _endpoints.front();
LOG_TOPIC(DEBUG, Logger::AGENCYCOMM) << "Using endpoint " << endpoint
<< " for agency communication, full selection:";
}
if (!_unusedConnections[endpoint].empty()) {
connection.reset(_unusedConnections[endpoint].back().release());
_unusedConnections[endpoint].pop_back();
} else {
connection = createNewConnection();
}
}
LOG_TOPIC(TRACE, Logger::AGENCYCOMM)
<< "acquiring agency connection '" << connection.get() << "' for endpoint '"
<< endpoint << "'";
return connection;
}
void AgencyCommManager::release(
std::unique_ptr<httpclient::GeneralClientConnection> connection,
std::string const& endpoint) {
MUTEX_LOCKER(locker, _lock);
if (_endpoints.front() == endpoint) {
LOG_TOPIC(TRACE, Logger::AGENCYCOMM)
<< "releasing agency connection '" << connection.get()
<< "', active endpoint '" << endpoint << "'";
} else {
LOG_TOPIC(TRACE, Logger::AGENCYCOMM)
<< "releasing agency connection '" << connection.get()
<< "', inactive endpoint '" << endpoint << "'";
}
_unusedConnections[endpoint].emplace_back(std::move(connection));
}
void AgencyCommManager::failed(
std::unique_ptr<httpclient::GeneralClientConnection> connection,
std::string const& endpoint) {
MUTEX_LOCKER(locker, _lock);
failedNonLocking(std::move(connection), endpoint);
}
void AgencyCommManager::failedNonLocking(
std::unique_ptr<httpclient::GeneralClientConnection> connection,
std::string const& endpoint) {
if (_endpoints.front() == endpoint) {
LOG_TOPIC(TRACE, Logger::AGENCYCOMM)
<< "failed agency connection '" << connection.get()
<< "', active endpoint " << endpoint << "'";
} else {
LOG_TOPIC(TRACE, Logger::AGENCYCOMM)
<< "failed agency connection '" << connection.get()
<< "', inactive endpoint " << endpoint << "'";
}
switchCurrentEndpoint();
_unusedConnections[endpoint].clear();
}
template<class T>
inline std::ostream& operator<<(std::ostream& o, std::deque<T> const& d) {
for (const auto& i : d) {
o << i << " ";
}
return o;
}
std::string AgencyCommManager::redirect(
std::unique_ptr<httpclient::GeneralClientConnection> connection,
std::string const& endpoint, std::string const& location,
std::string& url) {
MUTEX_LOCKER(locker, _lock);
std::string specification;
size_t delim = std::string::npos;
if (location.substr(0, 7) == "http://") {
specification = "http+tcp://" + location.substr(7);
delim = specification.find_first_of('/', 12);
} else if (location.substr(0, 8) == "https://") {
specification = "http+ssl://" + location.substr(8);
delim = specification.find_first_of('/', 13);
}
// invalid location header
if (delim == std::string::npos) {
failedNonLocking(std::move(connection), endpoint);
return "";
}
std::string rest = specification.substr(delim);
specification = Endpoint::unifiedForm(specification.substr(0, delim));
LOG_TOPIC(TRACE, Logger::AGENCYCOMM)
<< "redirect: location = " << location << ", specification = "
<< specification << ", url = " << rest;
if (endpoint == specification) {
LOG_TOPIC(WARN, Logger::AGENCYCOMM)
<< "got an agency redirect back to the old agency '" << endpoint << "'";
failedNonLocking(std::move(connection), endpoint);
return "";
}
// TODO: What is this good for
if (endpoint != _endpoints.front()) {
LOG_TOPIC(DEBUG, Logger::AGENCYCOMM)
<< "ignoring an agency redirect to '" << specification
<< "' from inactive endpoint '" << endpoint << "'";
return "";
}
url = rest;
_endpoints.erase(
std::remove(_endpoints.begin(), _endpoints.end(), specification),
_endpoints.end());
LOG_TOPIC(WARN, Logger::AGENCYCOMM)
<< "got an agency redirect from '" << endpoint
<< "' to '" << specification << "'";
_endpoints.push_front(specification);
return specification;
}
void AgencyCommManager::addEndpoint(std::string const& endpoint) {
MUTEX_LOCKER(locker, _lock);
std::string normalized = Endpoint::unifiedForm(endpoint);
auto iter = _endpoints.begin();
for (; iter != _endpoints.end(); ++iter) {
if (*iter == normalized) {
break;
}
}
if (iter == _endpoints.end()) {
LOG_TOPIC(DEBUG, Logger::AGENCYCOMM) << "using agency endpoint '"
<< normalized << "'";
_endpoints.emplace_back(normalized);
}
}
void AgencyCommManager::removeEndpoint(std::string const& endpoint) {
MUTEX_LOCKER(locker, _lock);
std::string normalized = Endpoint::unifiedForm(endpoint);
_endpoints.erase(
std::remove(_endpoints.begin(), _endpoints.end(), normalized),
_endpoints.end());
}
std::string AgencyCommManager::endpointsString() const {
return StringUtils::join(endpoints(), ", ");
}
std::vector<std::string> AgencyCommManager::endpoints() const {
std::vector<std::string> result;
MUTEX_LOCKER(locker, _lock);
result.insert(result.begin(), _endpoints.begin(), _endpoints.end());
return result;
}
std::unique_ptr<GeneralClientConnection>
AgencyCommManager::createNewConnection() {
if (_endpoints.empty()) {
LOG_TOPIC(TRACE, Logger::AGENCYCOMM)
<< "no agency endpoint is know, cannot create connection";
return nullptr;
}
std::unique_ptr<Endpoint> endpoint(
Endpoint::clientFactory(_endpoints.front()));
return std::unique_ptr<GeneralClientConnection>(
GeneralClientConnection::factory(endpoint,
CONNECTION_OPTIONS._requestTimeout,
CONNECTION_OPTIONS._connectTimeout,
CONNECTION_OPTIONS._connectRetries, 0));
}
void AgencyCommManager::switchCurrentEndpoint() {
if (_endpoints.empty()) {
return;
}
std::string current = _endpoints.front();
_endpoints.pop_front();
_endpoints.push_back(current);
LOG_TOPIC(TRACE, Logger::AGENCYCOMM)
<< "switching active agency endpoint from '" << current << "' to '"
<< _endpoints.front() << "'";
}
// -----------------------------------------------------------------------------
// --SECTION-- AgencyComm
// -----------------------------------------------------------------------------
std::string const AgencyComm::AGENCY_URL_PREFIX = "/_api/agency";
AgencyCommResult AgencyComm::sendServerState(double ttl) {
// construct JSON value { "status": "...", "time": "..." }
VPackBuilder builder;
try {
builder.openObject();
std::string const status =
ServerState::stateToString(ServerState::instance()->getState());
builder.add("status", VPackValue(status));
std::string const stamp = AgencyCommManager::generateStamp();
builder.add("time", VPackValue(stamp));
builder.close();
} catch (...) {
return AgencyCommResult();
}
AgencyCommResult result(
setValue("Sync/ServerStates/" + ServerState::instance()->getId(),
builder.slice(), ttl));
return result;
}
std::string AgencyComm::version() {
AgencyCommResult result =
sendWithFailover(arangodb::rest::RequestType::GET,
AgencyCommManager::CONNECTION_OPTIONS._requestTimeout,
"/_api/version", "");
if (result.successful()) {
return result._body;
}
return "";
}
AgencyCommResult AgencyComm::createDirectory(std::string const& key) {
VPackBuilder builder;
{ VPackObjectBuilder dir(&builder); }
AgencyOperation operation(key, AgencyValueOperationType::SET,
builder.slice());
AgencyWriteTransaction transaction(operation);
return sendTransactionWithFailover(transaction);
}
AgencyCommResult AgencyComm::setValue(std::string const& key,
std::string const& value, double ttl) {
VPackBuilder builder;
builder.add(VPackValue(value));
AgencyOperation operation(key, AgencyValueOperationType::SET,
builder.slice());
operation._ttl = static_cast<uint32_t>(ttl);
AgencyWriteTransaction transaction(operation);
return sendTransactionWithFailover(transaction);
}
AgencyCommResult AgencyComm::setValue(std::string const& key,
arangodb::velocypack::Slice const& slice,
double ttl) {
AgencyOperation operation(key, AgencyValueOperationType::SET, slice);
operation._ttl = static_cast<uint32_t>(ttl);
AgencyWriteTransaction transaction(operation);
return sendTransactionWithFailover(transaction);
}
bool AgencyComm::exists(std::string const& key) {
AgencyCommResult result = getValues(key);
if (!result.successful()) {
return false;
}
auto parts = arangodb::basics::StringUtils::split(key, "/");
std::vector<std::string> allParts;
allParts.reserve(parts.size() + 1);
allParts.push_back(AgencyCommManager::path());
allParts.insert(allParts.end(), parts.begin(), parts.end());
VPackSlice slice = result.slice()[0].get(allParts);
return !slice.isNone();
}
AgencyCommResult AgencyComm::getValues(std::string const& key) {
std::string url = AgencyComm::AGENCY_URL_PREFIX + "/read";
VPackBuilder builder;
{
VPackArrayBuilder root(&builder);
{
VPackArrayBuilder keys(&builder);
builder.add(VPackValue(AgencyCommManager::path(key)));
}
}
AgencyCommResult result =
sendWithFailover(arangodb::rest::RequestType::POST,
AgencyCommManager::CONNECTION_OPTIONS._requestTimeout,
url, builder.toJson());
if (!result.successful()) {
return result;
}
try {
result.setVPack(VPackParser::fromJson(result.bodyRef()));
if (!result.slice().isArray()) {
result._statusCode = 500;
return result;
}
if (result.slice().length() != 1) {
result._statusCode = 500;
return result;
}
result._body.clear();
result._statusCode = 200;
} catch (std::exception const& e) {
LOG_TOPIC(ERR, Logger::AGENCYCOMM) << "Error transforming result. "
<< e.what();
result.clear();
} catch (...) {
LOG_TOPIC(ERR, Logger::AGENCYCOMM)
<< "Error transforming result. Out of memory";
result.clear();
}
return result;
}
AgencyCommResult AgencyComm::removeValues(std::string const& key,
bool recursive) {
AgencyWriteTransaction transaction(
AgencyOperation(key, AgencySimpleOperationType::DELETE_OP),
AgencyPrecondition(key, AgencyPrecondition::Type::EMPTY, false));
return sendTransactionWithFailover(transaction);
}
AgencyCommResult AgencyComm::increment(std::string const& key) {
AgencyWriteTransaction transaction(
AgencyOperation(key, AgencySimpleOperationType::INCREMENT_OP));
return sendTransactionWithFailover(transaction);
}
AgencyCommResult AgencyComm::casValue(std::string const& key,
arangodb::velocypack::Slice const& json,
bool prevExist, double ttl,
double timeout) {
VPackBuilder newBuilder;
newBuilder.add(json);
AgencyOperation operation(key, AgencyValueOperationType::SET,
newBuilder.slice());
AgencyPrecondition precondition(key, AgencyPrecondition::Type::EMPTY,
!prevExist);
if (ttl >= 0.0) {
operation._ttl = static_cast<uint32_t>(ttl);
}
VPackBuilder preBuilder;
precondition.toVelocyPack(preBuilder);
AgencyWriteTransaction transaction(operation, precondition);
return sendTransactionWithFailover(transaction, timeout);
}
AgencyCommResult AgencyComm::casValue(std::string const& key,
VPackSlice const& oldJson,
VPackSlice const& newJson, double ttl,
double timeout) {
VPackBuilder newBuilder;
newBuilder.add(newJson);
VPackBuilder oldBuilder;
oldBuilder.add(oldJson);
AgencyOperation operation(key, AgencyValueOperationType::SET,
newBuilder.slice());
AgencyPrecondition precondition(key, AgencyPrecondition::Type::VALUE,
oldBuilder.slice());
if (ttl >= 0.0) {
operation._ttl = static_cast<uint32_t>(ttl);
}
AgencyWriteTransaction transaction(operation, precondition);
return sendTransactionWithFailover(transaction, timeout);
}
uint64_t AgencyComm::uniqid(uint64_t count, double timeout) {
#ifdef DEBUG_SYNC_REPLICATION
if (AgencyComm::syncReplDebug == true) {
return debugUniqId++;
}
#endif
static int const maxTries = 1000000;
// this is pretty much forever, but we simply cannot continue at all
// if we do not get a unique id from the agency.
int tries = 0;
AgencyCommResult result;
uint64_t oldValue = 0;
while (tries++ < maxTries) {
result = getValues("Sync/LatestID");
if (!result.successful()) {
usleep(500000);
continue;
}
VPackSlice oldSlice = result.slice()[0].get(std::vector<std::string>(
{AgencyCommManager::path(), "Sync", "LatestID"}));
if (!(oldSlice.isSmallInt() || oldSlice.isUInt())) {
LOG_TOPIC(WARN, Logger::AGENCYCOMM)
<< "Sync/LatestID in agency is not an unsigned integer, fixing...";
try {
VPackBuilder builder;
builder.add(VPackValue(0));
// create the key on the fly
setValue("Sync/LatestID", builder.slice(), 0.0);
} catch (...) {
// Could not build local key. Try again
}
continue;
}
// If we get here, slice is pointing to an unsigned integer, which
// is the value in the agency.
oldValue = 0;
try {
oldValue = oldSlice.getUInt();
} catch (...) {
}
uint64_t const newValue = oldValue + count;
VPackBuilder newBuilder;
try {
newBuilder.add(VPackValue(newValue));
} catch (...) {
usleep(500000);
continue;
}
result =
casValue("Sync/LatestID", oldSlice, newBuilder.slice(), 0.0, timeout);
if (result.successful()) {
break;
}
// The cas did not work, simply try again!
}
return oldValue;
}
bool AgencyComm::registerCallback(std::string const& key,
std::string const& endpoint) {
VPackBuilder builder;
builder.add(VPackValue(endpoint));
AgencyOperation operation(key, AgencyValueOperationType::OBSERVE,
builder.slice());
AgencyWriteTransaction transaction(operation);
auto result = sendTransactionWithFailover(transaction);
return result.successful();
}
bool AgencyComm::unregisterCallback(std::string const& key,
std::string const& endpoint) {
VPackBuilder builder;
builder.add(VPackValue(endpoint));
AgencyOperation operation(key, AgencyValueOperationType::UNOBSERVE,
builder.slice());
AgencyWriteTransaction transaction(operation);
auto result = sendTransactionWithFailover(transaction);
return result.successful();
}
bool AgencyComm::lockRead(std::string const& key, double ttl, double timeout) {
VPackBuilder builder;
try {
builder.add(VPackValue("READ"));
} catch (...) {
return false;
}
return lock(key, ttl, timeout, builder.slice());
}
bool AgencyComm::lockWrite(std::string const& key, double ttl, double timeout) {
VPackBuilder builder;
try {
builder.add(VPackValue("WRITE"));
} catch (...) {
return false;
}
return lock(key, ttl, timeout, builder.slice());
}
bool AgencyComm::unlockRead(std::string const& key, double timeout) {
VPackBuilder builder;
try {
builder.add(VPackValue("READ"));
} catch (...) {
return false;
}
return unlock(key, builder.slice(), timeout);
}
bool AgencyComm::unlockWrite(std::string const& key, double timeout) {
VPackBuilder builder;
try {
builder.add(VPackValue("WRITE"));
} catch (...) {
return false;
}
return unlock(key, builder.slice(), timeout);
}
AgencyCommResult AgencyComm::sendTransactionWithFailover(
AgencyTransaction const& transaction, double timeout) {
std::string url = AgencyComm::AGENCY_URL_PREFIX;
url += transaction.path();
VPackBuilder builder;
{
VPackArrayBuilder guard(&builder);
transaction.toVelocyPack(builder);
}
LOG_TOPIC(TRACE, Logger::AGENCYCOMM)
<< "sending " << builder.toJson() << "'" << url << "'";
AgencyCommResult result = sendWithFailover(
arangodb::rest::RequestType::POST,
(timeout == 0.0 ? AgencyCommManager::CONNECTION_OPTIONS._requestTimeout
: timeout),
url, builder.slice().toJson());
try {
result.setVPack(VPackParser::fromJson(result.bodyRef()));
if (!transaction.validate(result)) {
result._statusCode = 500;
return result;
}
result._body.clear();
} catch (std::exception const& e) {
LOG_TOPIC(ERR, Logger::AGENCYCOMM) << "Error transforming result. "
<< e.what();
result.clear();
} catch (...) {
LOG_TOPIC(ERR, Logger::AGENCYCOMM)
<< "Error transforming result. Out of memory";
result.clear();
}
return result;
}
bool AgencyComm::ensureStructureInitialized() {
LOG_TOPIC(TRACE, Logger::AGENCYCOMM) << "checking if agency is initialized";
AuthenticationFeature* authentication =
application_features::ApplicationServer::getFeature<
AuthenticationFeature>("Authentication");
TRI_ASSERT(authentication != nullptr);
while (true) {
while (shouldInitializeStructure()) {
LOG_TOPIC(TRACE, Logger::AGENCYCOMM)
<< "Agency is fresh. Needs initial structure.";
// mop: we initialized it .. great success
std::string secret;
if (authentication->isEnabled()) {
secret = authentication->jwtSecret();
}
if (tryInitializeStructure(secret)) {
LOG_TOPIC(TRACE, Logger::AGENCYCOMM)
<< "Successfully initialized agency";
break;
}
LOG_TOPIC(WARN, Logger::AGENCYCOMM)
<< "Initializing agency failed. We'll try again soon";
// We should really have exclusive access, here, this is strange!
sleep(1);
}
AgencyCommResult result = getValues("InitDone");
if (result.successful()) {
VPackSlice value = result.slice()[0].get(
std::vector<std::string>({AgencyCommManager::path(), "InitDone"}));
if (value.isBoolean() && value.getBoolean()) {
// expecting a value of "true"
LOG_TOPIC(TRACE, Logger::AGENCYCOMM) << "Found an initialized agency";
break;
}
}
LOG_TOPIC(TRACE, Logger::AGENCYCOMM)
<< "Waiting for agency to get initialized";
sleep(1);
}
AgencyCommResult secretResult = getValues("Secret");
VPackSlice secretValue = secretResult.slice()[0].get(
std::vector<std::string>({AgencyCommManager::path(), "Secret"}));
if (!secretValue.isString()) {
LOG(ERR) << "Couldn't find secret in agency!";
return false;
}
std::string const secret = secretValue.copyString();
if (!secret.empty()) {
authentication->setJwtSecret(secretValue.copyString());
}
return true;
}
bool AgencyComm::lock(std::string const& key, double ttl, double timeout,
VPackSlice const& slice) {
if (ttl == 0.0) {
ttl = AgencyCommManager::CONNECTION_OPTIONS._lockTimeout;
}
if (timeout == 0.0) {
timeout = AgencyCommManager::CONNECTION_OPTIONS._lockTimeout;
}
unsigned long sleepTime = INITIAL_SLEEP_TIME;
double const end = TRI_microtime() + timeout;
VPackBuilder builder;
try {
builder.add(VPackValue("UNLOCKED"));
} catch (...) {
return false;
}
VPackSlice oldSlice = builder.slice();
while (true) {
AgencyCommResult result =
casValue(key + "/Lock", oldSlice, slice, ttl, timeout);
if (!result.successful() &&
result.httpCode() ==
(int)arangodb::rest::ResponseCode::PRECONDITION_FAILED) {
// key does not yet exist. create it now
result = casValue(key + "/Lock", slice, false, ttl, timeout);
}
if (result.successful()) {
return true;
}
usleep(sleepTime);
if (sleepTime < MAX_SLEEP_TIME) {
sleepTime += INITIAL_SLEEP_TIME;
}
if (TRI_microtime() >= end) {
return false;
}
}
TRI_ASSERT(false);
return false;
}
bool AgencyComm::unlock(std::string const& key, VPackSlice const& slice,
double timeout) {
if (timeout == 0.0) {
timeout = AgencyCommManager::CONNECTION_OPTIONS._lockTimeout;
}
unsigned long sleepTime = INITIAL_SLEEP_TIME;
double const end = TRI_microtime() + timeout;
VPackBuilder builder;
try {
builder.add(VPackValue("UNLOCKED"));
} catch (...) {
// Out of Memory
return false;
}
VPackSlice newSlice = builder.slice();
while (true) {
AgencyCommResult result =
casValue(key + "/Lock", slice, newSlice, 0.0, timeout);
if (result.successful()) {
return true;
}
usleep(sleepTime);
if (sleepTime < MAX_SLEEP_TIME) {
sleepTime += INITIAL_SLEEP_TIME;
}
if (TRI_microtime() >= end) {
return false;
}
}
TRI_ASSERT(false);
return false;
}
void AgencyComm::updateEndpoints(arangodb::velocypack::Slice const& current) {
auto stored = AgencyCommManager::MANAGER->endpoints();
for (const auto& i : VPackObjectIterator(current)) {
auto const endpoint = Endpoint::unifiedForm(i.value.copyString());
if (std::find(stored.begin(), stored.end(), endpoint) == stored.end()) {
LOG_TOPIC(INFO, Logger::CLUSTER)
<< "Adding endpoint " << endpoint << " to agent pool";
AgencyCommManager::MANAGER->addEndpoint(endpoint);
}
stored.erase(
std::remove(stored.begin(), stored.end(), endpoint), stored.end());
}
for (const auto& i : stored) {
LOG_TOPIC(INFO, Logger::CLUSTER)
<< "Removing endpoint " << i << " from agent pool";
AgencyCommManager::MANAGER->removeEndpoint(i);
}
}
AgencyCommResult AgencyComm::sendWithFailover(
arangodb::rest::RequestType method, double const timeout,
std::string const& initialUrl, std::string const& body) {
std::string endpoint;
std::unique_ptr<GeneralClientConnection> connection =
AgencyCommManager::MANAGER->acquire(endpoint);
AgencyCommResult result;
std::string url = initialUrl;
std::chrono::duration<double> waitInterval (.25); // seconds
auto started = std::chrono::steady_clock::now();
auto timeOut = std::chrono::steady_clock::now() +
std::chrono::duration<double>(timeout);
double conTimeout = 1.0;
int tries = 0;
while (true) { // will be left by timeout eventually
// Raise waits to a maximum 10 seconds
auto waitUntil = std::chrono::steady_clock::now() + waitInterval;
// timeout exit startegy
if (std::chrono::steady_clock::now() < timeOut) {
if (tries > 0) {
std::this_thread::sleep_for(waitUntil-std::chrono::steady_clock::now());
if (waitInterval.count() < 5.0) {
waitInterval *= 1.5;
}
}
} else {
LOG_TOPIC(DEBUG, Logger::AGENCYCOMM)
<< "Unsuccessful AgencyComm: Timeout"
<< "errorCode: " << result.errorCode()
<< " errorMessage: " << result.errorMessage()
<< " errorDetails: " << result.errorDetails();
return result;
}
++tries;
if (connection == nullptr) {
AgencyCommResult result(400, "No endpoints for agency found.");
LOG_TOPIC(ERR, Logger::AGENCYCOMM) << result._message;
return result;
}
if (1 < tries) {
LOG_TOPIC(WARN, Logger::AGENCYCOMM)
<< "Retrying agency communication at '" << endpoint
<< "', tries: " << tries << " ("
<< 1.e-2 * (
std::round(
1.e+2 * std::chrono::duration<double>(
std::chrono::steady_clock::now() - started).count())) << "s)";
}
// try to send; if we fail completely, do not retry
try {
result = send(connection.get(), method, conTimeout, url, body);
} catch (...) {
AgencyCommManager::MANAGER->failed(std::move(connection), endpoint);
endpoint.clear();
connection = AgencyCommManager::MANAGER->acquire(endpoint);
continue;
}
// got a result, we are done
if (result.successful()) {
AgencyCommManager::MANAGER->release(std::move(connection), endpoint);
break;
}
// break on a watch timeout (drop connection)
if (result._statusCode == 0) {
AgencyCommManager::MANAGER->failed(std::move(connection), endpoint);
endpoint.clear();
connection = AgencyCommManager::MANAGER->acquire(endpoint);
continue;
}
// sometimes the agency will return a 307 (temporary redirect)
// in this case we have to pick it up and use the new location returned
if (result._statusCode ==
(int)arangodb::rest::ResponseCode::TEMPORARY_REDIRECT) {
endpoint = AgencyCommManager::MANAGER->redirect(
std::move(connection), endpoint, result._location, url);
connection = AgencyCommManager::MANAGER->acquire(endpoint);
waitInterval = std::chrono::duration<double>(.25);
continue;
}
// do not retry on client errors
if (result._statusCode >= 400 && result._statusCode <= 499) {
AgencyCommManager::MANAGER->release(std::move(connection), endpoint);
break;
}
// here we have failed and want to try next endpoint
AgencyCommManager::MANAGER->failed(std::move(connection), endpoint);
endpoint.clear();
connection = AgencyCommManager::MANAGER->acquire(endpoint);
}
// other error
if (!result.successful() && result.httpCode() != 412) {
LOG_TOPIC(DEBUG, Logger::AGENCYCOMM)
<< "Unsuccessful AgencyComm: "
<< "errorCode: " << result.errorCode()
<< " errorMessage: " << result.errorMessage()
<< " errorDetails: " << result.errorDetails();
}
return result;
}
AgencyCommResult AgencyComm::send(
arangodb::httpclient::GeneralClientConnection* connection,
arangodb::rest::RequestType method, double timeout, std::string const& url,
std::string const& body) {
TRI_ASSERT(connection != nullptr);
if (method == arangodb::rest::RequestType::GET ||
method == arangodb::rest::RequestType::HEAD ||
method == arangodb::rest::RequestType::DELETE_REQ) {
TRI_ASSERT(body.empty());
}
TRI_ASSERT(!url.empty());
AgencyCommResult result;
result._connected = false;
result._statusCode = 0;
LOG_TOPIC(TRACE, Logger::AGENCYCOMM)
<< "sending " << arangodb::HttpRequest::translateMethod(method)
<< " request to agency at endpoint '"
<< connection->getEndpoint()->specification() << "', url '" << url
<< "': " << body;
arangodb::httpclient::SimpleHttpClient client(connection, timeout, false);
client.setJwt(ClusterComm::instance()->jwt());
client.keepConnectionOnDestruction(true);
// set up headers
std::unordered_map<std::string, std::string> headers;
if (method == arangodb::rest::RequestType::POST) {
// the agency needs this content-type for the body
headers["content-type"] = "application/json";
}
// send the actual request
std::unique_ptr<arangodb::httpclient::SimpleHttpResult> response(
client.request(method, url, body.c_str(), body.size(), headers));
if (response == nullptr) {
result._message = "could not send request to agency";
LOG_TOPIC(TRACE, Logger::AGENCYCOMM) << "could not send request to agency";
return result;
}
if (!response->isComplete()) {
result._message = "sending request to agency failed";
LOG_TOPIC(TRACE, Logger::AGENCYCOMM) << "sending request to agency failed";
return result;
}
result._connected = true;
if (response->getHttpReturnCode() ==
(int)arangodb::rest::ResponseCode::TEMPORARY_REDIRECT) {
// temporary redirect. now save location header
bool found = false;
result._location = response->getHeaderField(StaticStrings::Location, found);
LOG_TOPIC(TRACE, Logger::AGENCYCOMM) << "redirecting to location: '"
<< result._location << "'";
if (!found) {
// a 307 without a location header does not make any sense
result._message = "invalid agency response (header missing)";
return result;
}
}
result._message = response->getHttpReturnMessage();
result._statusCode = response->getHttpReturnCode();
basics::StringBuffer& sb = response->getBody();
result._body = std::string(sb.c_str(), sb.length());
LOG_TOPIC(TRACE, Logger::AGENCYCOMM)
<< "request to agency returned status code " << result._statusCode
<< ", message: '" << result._message << "', body: '" << result._body
<< "'";
return result;
}
bool AgencyComm::tryInitializeStructure(std::string const& jwtSecret) {
VPackBuilder builder;
try {
VPackObjectBuilder b(&builder);
builder.add(VPackValue("Sync"));
{
VPackObjectBuilder c(&builder);
builder.add("LatestID", VPackValue(1));
addEmptyVPackObject("Problems", builder);
builder.add("UserVersion", VPackValue(1));
addEmptyVPackObject("ServerStates", builder);
builder.add("HeartbeatIntervalMs", VPackValue(1000));
addEmptyVPackObject("Commands", builder);
}
builder.add(VPackValue("Current"));
{
VPackObjectBuilder c(&builder);
builder.add(VPackValue("Collections"));
{
VPackObjectBuilder d(&builder);
addEmptyVPackObject("_system", builder);
}
builder.add("Version", VPackValue(1));
addEmptyVPackObject("ShardsCopied", builder);
addEmptyVPackObject("NewServers", builder);
addEmptyVPackObject("Coordinators", builder);
builder.add("Lock", VPackValue("UNLOCKED"));
addEmptyVPackObject("DBServers", builder);
builder.add(VPackValue("ServersRegistered"));
{
VPackObjectBuilder c(&builder);
builder.add("Version", VPackValue("1"));
}
addEmptyVPackObject("Databases", builder);
}
builder.add(VPackValue("Plan"));
{
VPackObjectBuilder c(&builder);
addEmptyVPackObject("Coordinators", builder);
builder.add(VPackValue("Databases"));
{
VPackObjectBuilder d(&builder);
builder.add(VPackValue("_system"));
{
VPackObjectBuilder d2(&builder);
builder.add("name", VPackValue("_system"));
builder.add("id", VPackValue("1"));
}
}
builder.add("Lock", VPackValue("UNLOCKED"));
addEmptyVPackObject("DBServers", builder);
builder.add("Version", VPackValue(1));
builder.add(VPackValue("Collections"));
{
VPackObjectBuilder d(&builder);
addEmptyVPackObject("_system", builder);
}
}
builder.add(VPackValue("Target"));
{
VPackObjectBuilder c(&builder);
builder.add(VPackValue("Collections"));
{
VPackObjectBuilder d(&builder);
addEmptyVPackObject("_system", builder);
}
addEmptyVPackObject("Coordinators", builder);
addEmptyVPackObject("DBServers", builder);
builder.add(VPackValue("Databases"));
{
VPackObjectBuilder d(&builder);
builder.add(VPackValue("_system"));
{
VPackObjectBuilder d2(&builder);
builder.add("name", VPackValue("_system"));
builder.add("id", VPackValue("1"));
}
}
builder.add("NumberOfCoordinators", VPackSlice::nullSlice());
builder.add("NumberOfDBServers", VPackSlice::nullSlice());
builder.add(VPackValue("CleanedServers"));
{ VPackArrayBuilder dd(&builder); }
builder.add(VPackValue("FailedServers"));
{ VPackObjectBuilder dd(&builder); }
builder.add("Lock", VPackValue("UNLOCKED"));
addEmptyVPackObject("MapLocalToID", builder);
addEmptyVPackObject("Failed", builder);
addEmptyVPackObject("Finished", builder);
addEmptyVPackObject("Pending", builder);
addEmptyVPackObject("ToDo", builder);
builder.add("Version", VPackValue(1));
}
builder.add(VPackValue("Supervision"));
{
VPackObjectBuilder c(&builder);
addEmptyVPackObject("Health", builder);
addEmptyVPackObject("Shards", builder);
addEmptyVPackObject("DBServers", builder);
}
builder.add("InitDone", VPackValue(true));
builder.add("Secret", VPackValue(jwtSecret));
} catch (std::exception const& e) {
LOG_TOPIC(ERR, Logger::AGENCYCOMM)
<< "Couldn't create initializing structure " << e.what();
return false;
} catch (...) {
LOG_TOPIC(ERR, Logger::AGENCYCOMM)
<< "Couldn't create initializing structure";
return false;
}
try {
LOG_TOPIC(TRACE, Logger::AGENCYCOMM) << "Initializing agency with "
<< builder.toJson();
AgencyOperation initOperation("", AgencyValueOperationType::SET,
builder.slice());
AgencyWriteTransaction initTransaction;
initTransaction.operations.push_back(initOperation);
auto result = sendTransactionWithFailover(initTransaction);
return result.successful();
} catch (std::exception const& e) {
LOG(FATAL) << "Fatal error initializing agency " << e.what();
FATAL_ERROR_EXIT();
} catch (...) {
LOG(FATAL) << "Fatal error initializing agency";
FATAL_ERROR_EXIT();
}
}
bool AgencyComm::shouldInitializeStructure() {
VPackBuilder builder;
builder.add(VPackValue(false));
// "InitDone" key should not previously exist
auto result = casValue("InitDone", builder.slice(), false, 60.0,
AgencyCommManager::CONNECTION_OPTIONS._requestTimeout);
if (!result.successful()) {
// somebody else has or is initializing the agency
LOG_TOPIC(TRACE, Logger::AGENCYCOMM)
<< "someone else is initializing the agency";
return false;
}
return true;
}
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