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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 "HaBroker.h"
#include "QueueReplicator.h"
#include "ReplicatingSubscription.h"
#include "qpid/broker/Bridge.h"
#include "qpid/broker/Broker.h"
#include "qpid/broker/Link.h"
#include "qpid/broker/Queue.h"
#include "qpid/broker/QueueRegistry.h"
#include "qpid/broker/SessionHandler.h"
#include "qpid/framing/SequenceSet.h"
#include "qpid/framing/FieldTable.h"
#include "qpid/log/Statement.h"
#include "qpid/Msg.h"
#include <boost/shared_ptr.hpp>
namespace {
const std::string QPID_REPLICATOR_("qpid.replicator-");
const std::string TYPE_NAME("qpid.queue-replicator");
const std::string QPID_SYNC_FREQUENCY("qpid.sync_frequency");
}
namespace qpid {
namespace ha {
using namespace broker;
using namespace framing;
const std::string QPID_HA_EVENT_PREFIX("qpid.ha-event:");
const std::string QueueReplicator::DEQUEUE_EVENT_KEY(QPID_HA_EVENT_PREFIX+"dequeue");
const std::string QueueReplicator::POSITION_EVENT_KEY(QPID_HA_EVENT_PREFIX+"position");
std::string QueueReplicator::replicatorName(const std::string& queueName) {
return QPID_REPLICATOR_ + queueName;
}
bool QueueReplicator::isEventKey(const std::string key) {
const std::string& prefix = QPID_HA_EVENT_PREFIX;
bool ret = key.size() > prefix.size() && key.compare(0, prefix.size(), prefix) == 0;
return ret;
}
QueueReplicator::QueueReplicator(HaBroker& hb,
boost::shared_ptr<Queue> q,
boost::shared_ptr<Link> l)
: Exchange(replicatorName(q->getName()), 0, q->getBroker()),
haBroker(hb),
logPrefix("Backup queue "+q->getName()+": "),
queue(q), link(l), brokerInfo(hb.getBrokerInfo())
{
Uuid uuid(true);
bridgeName = replicatorName(q->getName()) + std::string(".") + uuid.str();
}
// This must be separate from the constructor so we can call shared_from_this.
void QueueReplicator::activate() {
sys::Mutex::ScopedLock l(lock);
std::pair<Bridge::shared_ptr, bool> result =
queue->getBroker()->getLinks().declare(
bridgeName,
*link,
false, // durable
queue->getName(), // src
getName(), // dest
"", // key
false, // isQueue
false, // isLocal
"", // id/tag
"", // excludes
false, // dynamic
0, // sync?
// Include shared_ptr to self to ensure we are not deleted
// before initializeBridge is called.
boost::bind(&QueueReplicator::initializeBridge, shared_from_this(), _1, _2)
);
bridge = result.first;
}
QueueReplicator::~QueueReplicator() { deactivate(); }
void QueueReplicator::deactivate() {
// destroy the route
sys::Mutex::ScopedLock l(lock);
if (bridge) {
bridge->close();
bridge.reset();
QPID_LOG(debug, logPrefix << "Deactivated bridge " << bridgeName);
}
}
// Called in a broker connection thread when the bridge is created.
void QueueReplicator::initializeBridge(Bridge& bridge, SessionHandler& sessionHandler) {
sys::Mutex::ScopedLock l(lock);
AMQP_ServerProxy peer(sessionHandler.out);
const qmf::org::apache::qpid::broker::ArgsLinkBridge& args(bridge.getArgs());
FieldTable settings;
settings.setInt(ReplicatingSubscription::QPID_REPLICATING_SUBSCRIPTION, 1);
settings.setInt(QPID_SYNC_FREQUENCY, 1); // FIXME aconway 2012-05-22: optimize?
settings.setInt(ReplicatingSubscription::QPID_BACK,
queue->getPosition());
settings.setTable(ReplicatingSubscription::QPID_BROKER_INFO,
brokerInfo.asFieldTable());
SequenceNumber front;
if (ReplicatingSubscription::getFront(*queue, front)) {
settings.setInt(ReplicatingSubscription::QPID_FRONT, front);
QPID_LOG(debug, "QPID_FRONT for " << queue->getName() << " is " << front);
}
peer.getMessage().subscribe(
args.i_src, args.i_dest, 0/*accept-explicit*/, 1/*not-acquired*/,
false/*exclusive*/, "", 0, settings);
// FIXME aconway 2012-05-22: use a finite credit window?
peer.getMessage().flow(getName(), 0, 0xFFFFFFFF);
peer.getMessage().flow(getName(), 1, 0xFFFFFFFF);
qpid::Address primary;
link->getRemoteAddress(primary);
QPID_LOG(info, logPrefix << "Connected to " << primary << "(" << bridgeName << ")");
QPID_LOG(trace, logPrefix << "Subscription settings: " << settings);
}
namespace {
template <class T> T decodeContent(Message& m) {
std::string content = m.getContent();
Buffer buffer(const_cast<char*>(content.c_str()), content.size());
T result;
result.decode(buffer);
return result;
}
}
void QueueReplicator::dequeue(SequenceNumber n, sys::Mutex::ScopedLock&) {
// Thread safe: only calls thread safe Queue functions.
queue->dequeueMessageAt(n);
}
// Called in connection thread of the queues bridge to primary.
void QueueReplicator::route(Deliverable& msg)
{
try {
const std::string& key = msg.getMessage().getRoutingKey();
sys::Mutex::ScopedLock l(lock);
if (!isEventKey(key)) {
msg.deliverTo(queue);
// We are on a backup so the queue is not modified except via this.
QPID_LOG(trace, logPrefix << "Enqueued message " << queue->getPosition());
}
else if (key == DEQUEUE_EVENT_KEY) {
SequenceSet dequeues = decodeContent<SequenceSet>(msg.getMessage());
QPID_LOG(trace, logPrefix << "Dequeue: " << dequeues);
//TODO: should be able to optimise the following
for (SequenceSet::iterator i = dequeues.begin(); i != dequeues.end(); i++)
dequeue(*i, l);
}
else if (key == POSITION_EVENT_KEY) {
SequenceNumber position = decodeContent<SequenceNumber>(msg.getMessage());
QPID_LOG(trace, logPrefix << "Position moved from " << queue->getPosition()
<< " to " << position);
// Verify that there are no messages after the new position in the queue.
SequenceNumber next;
if (ReplicatingSubscription::getNext(*queue, position, next))
throw Exception("Invalid position move, preceeds messages");
queue->setPosition(position);
}
// Ignore unknown event keys, may be introduced in later versions.
}
catch (const std::exception& e) {
QPID_LOG(critical, logPrefix << "Replication failed: " << e.what());
haBroker.shutdown();
throw;
}
}
// Unused Exchange methods.
bool QueueReplicator::bind(boost::shared_ptr<Queue>, const std::string&, const FieldTable*, qpid::broker::AsyncStore* const) { return false; }
bool QueueReplicator::unbind(boost::shared_ptr<Queue>, const std::string&, const FieldTable*, qpid::broker::AsyncStore* const) { return false; }
bool QueueReplicator::isBound(boost::shared_ptr<Queue>, const std::string* const, const FieldTable* const) { return false; }
std::string QueueReplicator::getType() const { return TYPE_NAME; }
// DataSource interface - used to write persistence data to async store
uint64_t QueueReplicator::getSize() { return 0; }
void QueueReplicator::write(char* /*target*/) {}
}} // namespace qpid::broker
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