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/*
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.
*
*/
#include "Backup.h"
#include "HaBroker.h"
#include "Primary.h"
#include "ReplicationTest.h"
#include "ReplicatingSubscription.h"
#include "RemoteBackup.h"
#include "ConnectionObserver.h"
#include "qpid/assert.h"
#include "qpid/broker/Broker.h"
#include "qpid/broker/ConfigurationObserver.h"
#include "qpid/broker/Connection.h"
#include "qpid/broker/Queue.h"
#include "qpid/framing/FieldTable.h"
#include "qpid/log/Statement.h"
#include "qpid/sys/Timer.h"
#include <boost/bind.hpp>
namespace qpid {
namespace ha {
using sys::Mutex;
namespace {
class PrimaryConnectionObserver : public broker::ConnectionObserver
{
public:
PrimaryConnectionObserver(Primary& p) : primary(p) {}
void opened(broker::Connection& c) { primary.opened(c); }
void closed(broker::Connection& c) { primary.closed(c); }
private:
Primary& primary;
};
class PrimaryConfigurationObserver : public broker::ConfigurationObserver
{
public:
PrimaryConfigurationObserver(Primary& p) : primary(p) {}
void queueCreate(const Primary::QueuePtr& q) { primary.queueCreate(q); }
void queueDestroy(const Primary::QueuePtr& q) { primary.queueDestroy(q); }
private:
Primary& primary;
};
class ExpectedBackupTimerTask : public sys::TimerTask {
public:
ExpectedBackupTimerTask(Primary& p, sys::AbsTime deadline)
: TimerTask(deadline, "ExpectedBackupTimerTask"), primary(p) {}
void fire() { primary.timeoutExpectedBackups(); }
private:
Primary& primary;
};
} // namespace
Primary* Primary::instance = 0;
Primary::Primary(HaBroker& hb, const BrokerInfo::Set& expect) :
haBroker(hb), logPrefix("Primary: "), active(false)
{
assert(instance == 0);
instance = this; // Let queue replicators find us.
if (expect.empty()) {
QPID_LOG(notice, logPrefix << "Promoted to primary. No expected backups.");
}
else {
// NOTE: RemoteBackups must be created before we set the ConfigurationObserver
// or ConnectionObserver so that there is no client activity while
// the QueueGuards are created.
QPID_LOG(notice, logPrefix << "Promoted to primary. Expected backups: " << expect);
for (BrokerInfo::Set::const_iterator i = expect.begin(); i != expect.end(); ++i) {
boost::shared_ptr<RemoteBackup> backup(
new RemoteBackup(*i, haBroker.getReplicationTest(), false));
backups[i->getSystemId()] = backup;
if (!backup->isReady()) expectedBackups.insert(backup);
backup->setInitialQueues(hb.getBroker().getQueues(), true); // Create guards
}
// Set timeout for expected brokers to connect and become ready.
sys::Duration timeout(int64_t(hb.getSettings().backupTimeout*sys::TIME_SEC));
sys::AbsTime deadline(sys::now(), timeout);
timerTask = new ExpectedBackupTimerTask(*this, deadline);
hb.getBroker().getTimer().add(timerTask);
}
configurationObserver.reset(new PrimaryConfigurationObserver(*this));
haBroker.getBroker().getConfigurationObservers().add(configurationObserver);
Mutex::ScopedLock l(lock); // We are now active as a configurationObserver
checkReady(l);
// Allow client connections
connectionObserver.reset(new PrimaryConnectionObserver(*this));
haBroker.getObserver()->setObserver(connectionObserver);
}
Primary::~Primary() {
if (timerTask) timerTask->cancel();
haBroker.getBroker().getConfigurationObservers().remove(configurationObserver);
}
void Primary::checkReady(Mutex::ScopedLock&) {
if (!active && expectedBackups.empty()) {
active = true;
Mutex::ScopedUnlock u(lock); // Don't hold lock across callback
QPID_LOG(notice, logPrefix << "Finished waiting for backups, primary is active.");
haBroker.activate();
}
}
void Primary::checkReady(BackupMap::iterator i, Mutex::ScopedLock& l) {
if (i != backups.end() && i->second->reportReady()) {
BrokerInfo info = i->second->getBrokerInfo();
info.setStatus(READY);
haBroker.addBroker(info);
if (expectedBackups.erase(i->second)) {
QPID_LOG(info, logPrefix << "Expected backup is ready: " << info);
checkReady(l);
}
else
QPID_LOG(info, logPrefix << "New backup is ready: " << info);
}
}
void Primary::timeoutExpectedBackups() {
try {
sys::Mutex::ScopedLock l(lock);
if (active) return; // Already activated
// Remove records for any expectedBackups that are not yet connected
// Allow backups that are connected to continue becoming ready.
for (BackupSet::iterator i = expectedBackups.begin(); i != expectedBackups.end();)
{
boost::shared_ptr<RemoteBackup> rb = *i;
if (!rb->isConnected()) {
BrokerInfo info = rb->getBrokerInfo();
QPID_LOG(error, logPrefix << "Expected backup timed out: " << info);
expectedBackups.erase(i++);
backups.erase(info.getSystemId());
rb->cancel();
// Downgrade the broker to CATCHUP
info.setStatus(CATCHUP);
haBroker.addBroker(info);
}
else ++i;
}
checkReady(l);
}
catch(const std::exception& e) {
QPID_LOG(error, logPrefix << "Error timing out backups: " << e.what());
// No-where for this exception to go.
}
}
void Primary::readyReplica(const ReplicatingSubscription& rs) {
sys::Mutex::ScopedLock l(lock);
BackupMap::iterator i = backups.find(rs.getBrokerInfo().getSystemId());
if (i != backups.end()) {
i->second->ready(rs.getQueue());
checkReady(i, l);
}
}
void Primary::queueCreate(const QueuePtr& q) {
// Throw if there is an invalid replication level in the queue settings.
haBroker.getReplicationTest().replicateLevel(q->getSettings());
Mutex::ScopedLock l(lock);
for (BackupMap::iterator i = backups.begin(); i != backups.end(); ++i) {
i->second->queueCreate(q);
checkReady(i, l);
}
}
void Primary::queueDestroy(const QueuePtr& q) {
Mutex::ScopedLock l(lock);
for (BackupMap::iterator i = backups.begin(); i != backups.end(); ++i)
i->second->queueDestroy(q);
checkReady(l);
}
void Primary::opened(broker::Connection& connection) {
BrokerInfo info;
if (ha::ConnectionObserver::getBrokerInfo(connection, info)) {
Mutex::ScopedLock l(lock);
BackupMap::iterator i = backups.find(info.getSystemId());
if (i == backups.end()) {
boost::shared_ptr<RemoteBackup> backup(
new RemoteBackup(info, haBroker.getReplicationTest(), true));
{
// Avoid deadlock with queue registry lock.
Mutex::ScopedUnlock u(lock);
backup->setInitialQueues(haBroker.getBroker().getQueues(), false);
}
backups[info.getSystemId()] = backup;
QPID_LOG(debug, logPrefix << "New backup connected: " << info);
}
else {
QPID_LOG(debug, logPrefix << "Known backup connected: " << info);
i->second->setConnected(true);
checkReady(i, l);
}
if (info.getStatus() == JOINING) info.setStatus(CATCHUP);
haBroker.addBroker(info);
}
else
QPID_LOG(debug, logPrefix << "Accepted client connection "
<< connection.getMgmtId());
}
void Primary::closed(broker::Connection& connection) {
// NOTE: It is possible for a backup connection to be rejected while we are
// a backup, but closed() is called after we have become primary.
//
// For this reason we do not remove from the backups map here, the backups
// map holds all the backups we know about whether connected or not.
//
Mutex::ScopedLock l(lock);
BrokerInfo info;
if (ha::ConnectionObserver::getBrokerInfo(connection, info)) {
QPID_LOG(debug, logPrefix << "Backup disconnected: " << info);
haBroker.removeBroker(info.getSystemId());
BackupMap::iterator i = backups.find(info.getSystemId());
if (i != backups.end()) i->second->setConnected(false);
}
}
boost::shared_ptr<QueueGuard> Primary::getGuard(const QueuePtr& q, const BrokerInfo& info)
{
Mutex::ScopedLock l(lock);
BackupMap::iterator i = backups.find(info.getSystemId());
return i == backups.end() ? boost::shared_ptr<QueueGuard>() : i->second->guard(q);
}
}} // namespace qpid::ha
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