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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 "BrokerReplicator.h"
#include "ConnectionObserver.h"
#include "HaBroker.h"
#include "Primary.h"
#include "ReplicatingSubscription.h"
#include "Settings.h"
#include "StatusCheck.h"
#include "qpid/Url.h"
#include "qpid/amqp_0_10/Codecs.h"
#include "qpid/broker/Bridge.h"
#include "qpid/broker/Broker.h"
#include "qpid/broker/SessionHandler.h"
#include "qpid/broker/Link.h"
#include "qpid/framing/AMQP_ServerProxy.h"
#include "qpid/framing/AMQFrame.h"
#include "qpid/framing/FieldTable.h"
#include "qpid/framing/MessageTransferBody.h"
#include "qpid/sys/SystemInfo.h"
#include "qpid/types/Variant.h"
#include "qpid/log/Statement.h"
namespace qpid {
namespace ha {
using namespace framing;
using namespace broker;
using types::Variant;
using std::string;
using sys::Mutex;
Backup::Backup(HaBroker& hb, const Settings& s) :
logPrefix("Backup: "), membership(hb.getMembership()), stopped(false),
haBroker(hb), broker(hb.getBroker()), settings(s),
statusCheck(
new StatusCheck(
logPrefix, broker.getLinkHearbeatInterval(), hb.getBrokerInfo()))
{
// Set link properties to tag outgoing links.
framing::FieldTable linkProperties = broker.getLinkClientProperties();
linkProperties.setTable(
ConnectionObserver::BACKUP_TAG, hb.getBrokerInfo().asFieldTable());
broker.setLinkClientProperties(linkProperties);
}
void Backup::setBrokerUrl(const Url& brokers) {
if (brokers.empty()) return;
Mutex::ScopedLock l(lock);
if (stopped) return;
if (haBroker.getStatus() == JOINING) statusCheck->setUrl(brokers);
if (!link) { // Not yet initialized
QPID_LOG(info, logPrefix << "Connecting to cluster, broker URL: " << brokers);
string protocol = brokers[0].protocol.empty() ? "tcp" : brokers[0].protocol;
types::Uuid uuid(true);
std::pair<Link::shared_ptr, bool> result;
result = broker.getLinks().declare(
broker::QPID_NAME_PREFIX + string("ha.link.") + uuid.str(),
brokers[0].host, brokers[0].port, protocol,
false, // durable
settings.mechanism, settings.username, settings.password,
false); // no amq.failover - don't want to use client URL.
link = result.first;
replicator.reset(new BrokerReplicator(haBroker, link));
replicator->initialize();
broker.getExchanges().registerExchange(replicator);
}
link->setUrl(brokers); // Outside the lock, once set link doesn't change.
}
void Backup::stop(Mutex::ScopedLock&) {
if (stopped) return;
stopped = true;
QPID_LOG(debug, logPrefix << "Leaving backup role.");
if (link) link->close();
if (replicator.get()) {
replicator->shutdown();
replicator.reset();
}
}
Role* Backup::recover(Mutex::ScopedLock&) {
BrokerInfo::Set backups;
{
Mutex::ScopedLock l(lock);
if (stopped) return 0;
stop(l); // Stop backup activity before starting primary.
QPID_LOG(notice, "Promoting to primary: " << haBroker.getBrokerInfo());
// Reset membership before allowing backups to connect.
backups = membership.otherBackups();
membership.clear();
return new Primary(haBroker, backups);
}
}
Role* Backup::promote() {
Mutex::ScopedLock l(lock);
if (stopped) return 0;
switch (haBroker.getStatus()) {
case JOINING:
if (statusCheck->canPromote()) return recover(l);
else {
QPID_LOG(error,
logPrefix << "Joining active cluster, cannot be promoted.");
throw Exception("Joining active cluster, cannot be promoted.");
}
break;
case CATCHUP:
QPID_LOG(error, logPrefix << "Still catching up, cannot be promoted.");
throw Exception("Still catching up, cannot be promoted.");
break;
case READY: return recover(l); break;
default:
assert(0); // Not a valid state for the Backup role..
}
return 0; // Keep compiler happy
}
Backup::~Backup() {
Mutex::ScopedLock l(lock);
stop(l);
}
}} // namespace qpid::ha
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