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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.
*/
package org.apache.hadoop.hbase.replication.regionserver;
import java.util.Map;
import java.util.Queue;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.PriorityBlockingQueue;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
import org.apache.hadoop.hbase.wal.AbstractFSWALProvider;
import org.apache.yetus.audience.InterfaceAudience;
import org.apache.yetus.audience.InterfaceStability;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/*
Class that does enqueueing/dequeuing of wal at one place so that we can update the metrics
just at one place.
*/
@InterfaceAudience.Private
@InterfaceStability.Evolving
public class ReplicationSourceLogQueue {
private static final Logger LOG = LoggerFactory.getLogger(ReplicationSource.class);
// Queues of logs to process, entry in format of walGroupId->queue,
// each presents a queue for one wal group
private Map> queues = new ConcurrentHashMap<>();
private MetricsSource metrics;
private Configuration conf;
// per group queue size, keep no more than this number of logs in each wal group
private int queueSizePerGroup;
// WARN threshold for the number of queued logs, defaults to 2
private int logQueueWarnThreshold;
private ReplicationSource source;
public ReplicationSourceLogQueue(Configuration conf, MetricsSource metrics,
ReplicationSource source) {
this.conf = conf;
this.metrics = metrics;
this.source = source;
this.queueSizePerGroup = this.conf.getInt("hbase.regionserver.maxlogs", 32);
this.logQueueWarnThreshold = this.conf.getInt("replication.source.log.queue.warn", 2);
}
/**
* Enqueue the wal
* @param wal wal to be enqueued
* @param walGroupId Key for the wal in @queues map
* @return boolean whether this is the first time we are seeing this walGroupId.
*/
public boolean enqueueLog(Path wal, String walGroupId) {
boolean exists = false;
PriorityBlockingQueue queue = queues.get(walGroupId);
if (queue == null) {
queue = new PriorityBlockingQueue<>(queueSizePerGroup,
new AbstractFSWALProvider.WALStartTimeComparator());
// make sure that we do not use an empty queue when setting up a ReplicationSource, otherwise
// the shipper may quit immediately
queue.put(wal);
queues.put(walGroupId, queue);
} else {
exists = true;
queue.put(wal);
}
// Increment size of logQueue
this.metrics.incrSizeOfLogQueue();
// Compute oldest wal age
this.metrics.setOldestWalAge(getOldestWalAge());
// This will wal a warning for each new wal that gets created above the warn threshold
int queueSize = queue.size();
if (queueSize > this.logQueueWarnThreshold) {
LOG.warn("{} WAL group {} queue size: {} exceeds value of " +
"replication.source.log.queue.warn {}", source.logPeerId(), walGroupId, queueSize,
logQueueWarnThreshold);
}
return exists;
}
/**
* Get the queue size for the given walGroupId.
* @param walGroupId walGroupId
*/
public int getQueueSize(String walGroupId) {
Queue queue = queues.get(walGroupId);
if (queue == null) {
return 0;
}
return queue.size();
}
/**
* Returns number of queues.
*/
public int getNumQueues() {
return queues.size();
}
public Map> getQueues() {
return queues;
}
/**
* Return queue for the given walGroupId
* Please don't add or remove elements from the returned queue.
* Use @enqueueLog and @remove methods respectively.
* @param walGroupId walGroupId
*/
public PriorityBlockingQueue getQueue(String walGroupId) {
return queues.get(walGroupId);
}
/**
* Remove head from the queue corresponding to given walGroupId.
* @param walGroupId walGroupId
*/
public void remove(String walGroupId) {
PriorityBlockingQueue queue = getQueue(walGroupId);
if (queue == null || queue.isEmpty()) {
return;
}
queue.remove();
// Decrease size logQueue.
this.metrics.decrSizeOfLogQueue();
// Re-compute age of oldest wal metric.
this.metrics.setOldestWalAge(getOldestWalAge());
}
/**
* Remove all the elements from the queue corresponding to walGroupId
* @param walGroupId walGroupId
*/
public void clear(String walGroupId) {
PriorityBlockingQueue queue = getQueue(walGroupId);
while (!queue.isEmpty()) {
// Need to iterate since metrics#decrSizeOfLogQueue decrements just by 1.
queue.remove();
metrics.decrSizeOfLogQueue();
}
this.metrics.setOldestWalAge(getOldestWalAge());
}
/*
Returns the age of oldest wal.
*/
long getOldestWalAge() {
long now = EnvironmentEdgeManager.currentTime();
long timestamp = getOldestWalTimestamp();
if (timestamp == Long.MAX_VALUE) {
// If there are no wals in the queue then set the oldest wal timestamp to current time
// so that the oldest wal age will be 0.
timestamp = now;
}
long age = now - timestamp;
return age;
}
/*
Get the oldest wal timestamp from all the queues.
*/
private long getOldestWalTimestamp() {
long oldestWalTimestamp = Long.MAX_VALUE;
for (Map.Entry> entry : queues.entrySet()) {
PriorityBlockingQueue queue = entry.getValue();
Path path = queue.peek();
// Can path ever be null ?
if (path != null) {
oldestWalTimestamp = Math.min(oldestWalTimestamp,
AbstractFSWALProvider.WALStartTimeComparator.getTS(path));
}
}
return oldestWalTimestamp;
}
public MetricsSource getMetrics() {
return metrics;
}
}