/**
* Copyright 2012 Comcast Corporation
*
* 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.
*/
package com.comcast.cqs.persistence;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.security.NoSuchAlgorithmException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Random;
import java.util.Set;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicLong;
import me.prettyprint.hector.api.exceptions.HTimedOutException;
import org.apache.log4j.Logger;
import org.json.JSONException;
import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPoolConfig;
import redis.clients.jedis.JedisShardInfo;
import redis.clients.jedis.ShardedJedis;
import redis.clients.jedis.ShardedJedisPool;
import redis.clients.jedis.Transaction;
import redis.clients.jedis.exceptions.JedisConnectionException;
import redis.clients.jedis.exceptions.JedisException;
import com.comcast.cmb.common.persistence.AbstractDurablePersistence;
import com.comcast.cmb.common.util.CMBProperties;
import com.comcast.cmb.common.util.PersistenceException;
import com.comcast.cmb.common.util.ValueAccumulator.AccumulatorName;
import com.comcast.cqs.controller.CQSCache;
import com.comcast.cqs.controller.CQSControllerServlet;
import com.comcast.cqs.controller.CQSMonitor;
import com.comcast.cqs.controller.CQSMonitor.CacheType;
import com.comcast.cqs.model.CQSMessage;
import com.comcast.cqs.model.CQSQueue;
import com.comcast.cqs.persistence.RedisSortedSetPersistence.QCacheState;
import com.comcast.cqs.util.CQSConstants;
import com.comcast.cqs.util.Util;
/**
* This class uses Redis as cache in front of our Cassandra access.
* Currently we only cache message-ids and hidden/delayed state of messages.
* The payloads are fetched from underlying persistence layer.
*
* The class must exist as a singleton
* @author aseem, bwolf, vvenkatraman
*
* Class is thread-safe
*/
public class RedisCachedCassandraPersistence implements ICQSMessagePersistence {
private static final Logger logger = Logger.getLogger(RedisCachedCassandraPersistence.class);
private static final Random rand = new Random();
private static RedisCachedCassandraPersistence Inst;
public static ExecutorService executor;
public static ExecutorService revisibilityExecutor;
public final TestInterface testInterface = new TestInterface();
/**
*
* @return Singleton implementation of this object
*/
public static RedisCachedCassandraPersistence getInstance() {
return Inst;
}
private static JedisPoolConfig cfg = new JedisPoolConfig();
private static ShardedJedisPool pool;
private volatile static AtomicLong lastCheckMS = new AtomicLong(0);
private volatile static AtomicBoolean redisDown = new AtomicBoolean(false);
private static final long redisCheckFrequencyMS = 5000;
static {
initializeInstance();
initializePool();
}
private static void initializeInstance() {
CQSMessagePartitionedCassandraPersistence cassandraPersistence = new CQSMessagePartitionedCassandraPersistence();
Inst = new RedisCachedCassandraPersistence(cassandraPersistence);
}
private volatile ICQSMessagePersistence persistenceStorage;
private RedisCachedCassandraPersistence(ICQSMessagePersistence persistenceStorage) {
this.persistenceStorage = persistenceStorage;
}
/**
* Initialize the Redis connection pool
*/
private static void initializePool() {
cfg.setMaxTotal(CMBProperties.getInstance().getRedisConnectionsMaxTotal());
cfg.setMaxIdle(-1);
List<JedisShardInfo> shardInfos = new LinkedList<JedisShardInfo>();
String serverList = CMBProperties.getInstance().getRedisServerList();
if (serverList == null) {
throw new RuntimeException("Redis server list not specified");
}
String []arr = serverList.split(",");
for (int i = 0; i < arr.length; i++) {
String []hostPort = arr[i].trim().split(":");
JedisShardInfo shardInfo = null;
if (hostPort.length != 2) {
// use Redis default port if one wasn't specified
shardInfo = new JedisShardInfo(hostPort[0].trim(), 6379, 4000);
} else {
shardInfo = new JedisShardInfo(hostPort[0].trim(), Integer.parseInt(hostPort[1].trim()), 4000);
}
shardInfos.add(shardInfo);
}
pool = new ShardedJedisPool(cfg, shardInfos);
executor = Executors.newFixedThreadPool(CMBProperties.getInstance().getRedisFillerThreads());
revisibilityExecutor = Executors.newFixedThreadPool(CMBProperties.getInstance().getRedisRevisibleThreads());
logger.info("event=initialize_redis pools_size=" + shardInfos.size() + " max_total=" + cfg.getMaxTotal() + " server_list=" + serverList);
}
/**
* Possible states for queue
* State if Unavailable should be set when any code determines the queue is in bad state or unavailable.
* The checkCacheConsistency will take care of performing the appropriate actions on that queue
*/
public enum QCacheState {
Filling, //Cache is being filled by a thread
OK, //Cache is good for use
Unavailable; //Cache is unavailable for a single Q due to inconsistency issues.
}
public class TestInterface {
public void setCassandraPersistence(ICQSMessagePersistence pers) {
persistenceStorage = pers;
}
public ICQSMessagePersistence getCassandraPersistence() {
return persistenceStorage;
}
public QCacheState getCacheState(String q) {
return RedisCachedCassandraPersistence.this.getCacheState(q, 0);
}
public void setCacheState(String queueUrl, QCacheState state, QCacheState oldState, boolean checkOldState) throws SetFailedException {
RedisCachedCassandraPersistence.this.setCacheState(queueUrl, 0, state, oldState, checkOldState);
}
public String getMemQueueMessageMessageId(String queueUrlHash, String memId) {
return RedisCachedCassandraPersistence.getMemQueueMessageMessageId(queueUrlHash,memId);
}
public void resetTestQueue() {
ShardedJedis jedis = getResource();
try {
jedis.del("testQueue-0-" + CQSConstants.REDIS_STATE);
jedis.del("testQueue-0-Q");
jedis.del("testQueue-0-H");
jedis.del("testQueue-0-R");
jedis.del("testQueue-0-F");
jedis.del("testQueue-0-V");
jedis.del("testQueue-0-VR");
} finally {
returnResource(jedis);
}
}
public ShardedJedis getResource() {
return RedisCachedCassandraPersistence.getResource();
}
public void returnResource(ShardedJedis jedis) {
RedisCachedCassandraPersistence.returnResource(jedis, false);
}
public boolean checkCacheConsistency(String queueUrl) {
return RedisCachedCassandraPersistence.this.checkCacheConsistency(queueUrl, 0,false);
}
public void scheduleRevisibilityProcessor(String queueUrl) throws SetFailedException {
revisibilityExecutor.submit(new RevisibleProcessor(queueUrl, 0));
}
}
// each queue's state is represented by the HashTable with key <Q>-S and the states are defined in the enum QCacheState
static AtomicInteger numRedisConnections = new AtomicInteger(0);
public int getNumConnections() {
return numRedisConnections.get();
}
public static ShardedJedis getResource() {
ShardedJedis conn = pool.getResource();
numRedisConnections.incrementAndGet();
return conn;
}
public static void returnResource(ShardedJedis jedis, boolean broken) {
if (numRedisConnections.intValue() < 1) {
throw new IllegalStateException("Returned more connections than acquired from pool");
}
numRedisConnections.decrementAndGet();
if (broken) {
pool.returnBrokenResource(jedis);
} else {
pool.returnResource(jedis);
}
}
/**
* Class represents the race condition where the caller was beaten by someone else.
* In case of this exception, check the initial state again and retry if necessary.
*/
static class SetFailedException extends Exception {
private static final long serialVersionUID = 1L;
}
/**
*
* @param queueUrl
* @return The state of the queue or null if none exists
*/
private QCacheState getCacheState(String queueUrl, int shard) {
long ts1 = System.currentTimeMillis();
ShardedJedis jedis = getResource();
boolean brokenJedis = false;
try {
String st = jedis.hget(queueUrl + "-" + shard + "-" + CQSConstants.REDIS_STATE, CQSConstants.REDIS_STATE);
if (st == null) {
return null;
}
return QCacheState.valueOf(st);
} catch (JedisException e) {
brokenJedis = true;
throw e;
} finally {
returnResource(jedis, brokenJedis);
long ts2 = System.currentTimeMillis();
CQSControllerServlet.valueAccumulator.addToCounter(AccumulatorName.RedisTime, (ts2 - ts1));
}
}
/**
* Set the state for a queue or throw exception if someone else beat us to it.
* This is an atomic operation.
* @param queueUrl
* @param checkOldState - check the oldState in transaction
* @param oldState If checkOldstate is set we check within the WATCH..EXEC scope
* if the state is still the same as the old value. If not, we throw SetfailedException
* This helps do atomic CAS operations
* @param state State to set to. if null, then the state field is deleted
* @throws SetFailedException
*/
private void setCacheState(String queueUrl, int shard, QCacheState state, QCacheState oldState, boolean checkOldState) throws SetFailedException {
long ts1 = System.currentTimeMillis();
boolean brokenJedis = false;
ShardedJedis jedis = getResource();
try {
Jedis j = jedis.getShard(queueUrl + "-" + shard + "-" + CQSConstants.REDIS_STATE);
j.watch(queueUrl + "-" + shard + "-" + CQSConstants.REDIS_STATE);
if (checkOldState) {
String oldStateStr = j.hget(queueUrl + "-" + shard + "-" + CQSConstants.REDIS_STATE, CQSConstants.REDIS_STATE);
if (oldState == null && oldStateStr != null) {
throw new SetFailedException();
}
if (oldState != null) {
if (oldStateStr == null || QCacheState.valueOf(oldStateStr) != oldState) {
j.unwatch();
throw new SetFailedException();
}
}
}
Transaction tr = j.multi();
if (state == null) {
tr.hdel(queueUrl + "-" + shard + "-" + CQSConstants.REDIS_STATE, CQSConstants.REDIS_STATE);
} else {
tr.hset(queueUrl + "-" + shard + "-" + CQSConstants.REDIS_STATE, CQSConstants.REDIS_STATE, state.name());
}
List<Object> resp = tr.exec();
if (resp == null) {
throw new SetFailedException();
}
} catch(JedisException e) {
brokenJedis = true;
throw e;
} finally {
returnResource(jedis, brokenJedis);
long ts2 = System.currentTimeMillis();
CQSControllerServlet.valueAccumulator.addToCounter(AccumulatorName.RedisTime, (ts2 - ts1));
}
}
/**
* Sets the sentinel flag in Redis denoting either visibility processor is running or cache filler is
* running to prevent multiple from running and auto-expiring older runs.
* @param queueUrl
* @param visibilityOrCacheFiller
*/
private void setCacheFillerProcessing(String queueUrl, int shard, int exp) {
long ts1 = System.currentTimeMillis();
boolean brokenJedis = false;
ShardedJedis jedis = getResource();
String suffix = "-F";
try {
if (exp > 0) {
jedis.set(queueUrl + "-" + shard + suffix, "Y");
jedis.expire(queueUrl + "-" + shard + suffix, exp); //expire after exp seconds
} else {
jedis.del(queueUrl + "-" + shard + suffix);
}
} catch (JedisException e) {
brokenJedis = true;
throw e;
} finally {
returnResource(jedis, brokenJedis);
long ts2 = System.currentTimeMillis();
CQSControllerServlet.valueAccumulator.addToCounter(AccumulatorName.RedisTime, (ts2 - ts1));
}
}
// TODO: once we can expect people to have Redis 2.6.12 or newer, the set command takes additional arguments that will make this
// much simpler. It will also require a newer version of the Jedis library to support it.
// Example:
// String resp = j.set(redisKey,"Y","NX","EX",exp)
// return ( resp == nil)
//
private static boolean checkAndSetFlag(String queueUrl, int shard, String suffix, int exp) throws SetFailedException {
if (exp <= 0) {
throw new IllegalArgumentException("Redis expiration cannot be less than 0");
}
long ts1 = System.currentTimeMillis();
boolean brokenJedis = false;
String redisKey = queueUrl + "-" + shard + suffix;
ShardedJedis jedis = getResource();
try {
if (jedis.exists(redisKey)) {
return false;
}
Jedis j = jedis.getShard(redisKey);
j.watch(redisKey);
String val = j.get(redisKey);
if (val != null) {
j.unwatch();
return false;
}
Transaction tr = j.multi();
//sentinel expired. kick off new RevisibleProcessor job
tr.set(redisKey, "Y");
tr.expire(redisKey, exp); //expire after exp seconds
// since we have called watch, tr.exec will return null in the case that someone else has modified
// the redisKey since we started our transaction. If it doesn't return null, the value hasn't changed out from
// under us, so we return true since we set it
List<Object> resp = tr.exec();
return resp != null;
} catch (JedisException e) {
brokenJedis = true;
throw e;
} finally {
returnResource(jedis, brokenJedis);
long ts2 = System.currentTimeMillis();
CQSControllerServlet.valueAccumulator.addToCounter(AccumulatorName.RedisTime, (ts2 - ts1));
}
}
/**
* Check whether a visibility processing was kicked off within the last exp seconds. If not, kick one off.
* Method is atomic.
* @param queueUrl
* @param exp in seconds
* @return true if sentinel was set. false otherwise
*/
private boolean checkAndSetVisibilityProcessing(String queueUrl, int shard, int exp) throws SetFailedException {
if (checkAndSetFlag(queueUrl, shard, "-R", exp)) {
revisibilityExecutor.submit(new RevisibleProcessor(queueUrl, shard));
return true;
}
return false;
}
/**
* Processes the re-visible set once every exp seconds synchronously.
* @param queueUrl
* @param exp
* @return true if Revisible set processing was done. false otherwise
*/
private static boolean checkAndProcessRevisibleSet(String queueUrl, int shard, int exp) throws SetFailedException {
if (checkAndSetFlag(queueUrl, shard, "-VR", exp)) {
//perform re-visible set processing. Get all memIds whose score (visibilityTO) is <= now
long ts1 = System.currentTimeMillis();
long ts2 = 0;
boolean brokenJedis = false;
ShardedJedis jedis = getResource();
try {
//jedis is lame and does not have a constant for "-inf" which Redis supports. So we have to
//pick an arbitrary old min value.
Set<String> revisibleSet = jedis.zrangeByScore(queueUrl + "-" + shard + "-V", System.currentTimeMillis() - (1000 * 3600 * 24 * 14), System.currentTimeMillis());
for (String revisibleMemId : revisibleSet) {
jedis.rpush(queueUrl + "-" + shard + "-Q", revisibleMemId);
jedis.zrem(queueUrl + "-" + shard + "-V", revisibleMemId);
}
ts2 = System.currentTimeMillis();
if (revisibleSet.size() > 0) {
logger.debug("event=redis_revisibility queue_url=" + queueUrl + " shard=" + shard + " num_made_revisible=" + revisibleSet.size() + " res_ts=" + (ts2 - ts1));
}
} catch (JedisException e) {
brokenJedis = true;
throw e;
} finally {
returnResource(jedis, brokenJedis);
if (ts2 == 0) ts2 = System.currentTimeMillis();
CQSControllerServlet.valueAccumulator.addToCounter(AccumulatorName.RedisTime, (ts2 - ts1));
}
return true;
}
return false;
}
private static boolean tryCheckAndProcessRevisibleSet(String queueUrl, int shard, int exp) {
try {
if (checkAndProcessRevisibleSet(queueUrl, shard, exp)) {
return true;
} else {
return false;
}
} catch (SetFailedException e) {
return false;
}
}
private boolean getProcessingState(String queueUrl, int shard, boolean visibilityOrCacheFiller) {
long ts1 = System.currentTimeMillis();
boolean brokenJedis = false;
ShardedJedis jedis = getResource();
String suffix = visibilityOrCacheFiller ? "-R" : "-F";
try {
return jedis.exists(queueUrl + "-" + shard + suffix);
} catch (JedisException e) {
brokenJedis = true;
throw e;
} finally {
returnResource(jedis, brokenJedis);
long ts2 = System.currentTimeMillis();
CQSControllerServlet.valueAccumulator.addToCounter(AccumulatorName.RedisTime, (ts2 - ts1));
}
}
//below are helper methods for encoding Cassandra-message-id into in-memory message-id
/**
* In memory message has format addedTS:initialDelay:<messge-id>
* example - 1335302314:0:ABCDEFGHIJK
* @param messageId The Cassandra message-id
* @return The in-memory message-id
*/
private String getMemQueueMessage(String messageId) {
if (messageId.length() == 0) {
throw new IllegalArgumentException("Messge Id cannot be an empty string");
}
//messageID is like 45c1596598f85ce59f060dc2b8ec4ebb_0_72:2923737900040323074:-8763141905575923938
//the first part 45c1596598f85ce59f060dc2b8ec4ebb is hash of queue url, so replace it with 0 to save space in Redis
//return example: 0:0:0_0_72:2923737900040323074:-8763141905575923938
StringBuffer sb = new StringBuffer();
sb.append("0").append(':').append("0").append(":0").append(messageId.substring(messageId.indexOf("_")));
return sb.toString();
}
/**
*
* @param memId
* @return The created timestamp encoded in the memId
*/
//Example 0:0:0_0_72:2923737900040323074:-8763141905575923938
public long getMemQueueMessageCreatedTS(String memId) {
String []arr = memId.split(":");
if (arr.length < 5) {
throw new IllegalArgumentException("Bad format for memId. Must be of the form 0:0:<messge-id>. Got: " + memId);
}
return AbstractDurablePersistence.getTimestampFromHash(Long.parseLong(arr[3]));
}
/**
*
* @param memId
* @return The initial delay encoded in the memId
*/
private int getMemQueueMessageInitialDelay(String memId) {
String []arr = memId.split(":");
if (arr.length < 3) {
throw new IllegalArgumentException("Bad format for memId. Must be of the form 0:0:<messge-id>. Got: " + memId);
}
return Integer.parseInt(arr[1]);
}
/**
* @param memId
* @return The message-id encoded in memId
*/
static String getMemQueueMessageMessageId(String queueUrlHash, String memId) {
String []arr = memId.split(":");
if (arr.length < 3) {
throw new IllegalArgumentException("Bad format for memId. Must be of the form 0:0:<messge-id>. Got: " + memId);
}
//memId example: 0:0:0_0_72:2923737900040323074:-8763141905575923938
//replace arr[2] first 0 to queueUrlHash and return example: 45c1596598f85ce59f060dc2b8ec4ebb_0_72:2923737900040323074:-8763141905575923938
StringBuffer sb = new StringBuffer(queueUrlHash);
sb.append(arr[2].substring(arr[2].indexOf("_")));
for (int i = 3; i < arr.length; i++) {
sb.append(":").append(arr[i]);
}
return sb.toString();
}
/**
* Class clears and then fills the cache for a given queue
* When its done, it updates the following cache keys are available:
* <Q>-S = OK
* <Q>-Q = The in-memory list ("queue") of message ids
* <Q>-H = The hash table of hidden message ids along with the timestamp for when they should become re-visible
* <Q>-R = Existence implies recent processing of revisibility
* <Q>-F = Existence implies currently running CacheFiller
* <Q>-V = Set of delayed message ids implemented as a sorted set. Delayed messages cannot be deleted before they
* become visible. We synchronously retrieve due message ids from this set every so often as part of receivemessage()
* <Q>-VR = the sentinel flag the absence of which implies its time to process the delayed set.
* <Q>-A-<messageId> = The attributes for a message in a queue. Note, this requires that the messageId remain the same
* throughout the life-time of a message.
*/
private class CacheFiller implements Runnable {
final String queueUrl;
final int shard;
public CacheFiller(String queueUrl, int shard) {
this.queueUrl = queueUrl;
this.shard = shard;
}
@Override
public void run() {
CQSControllerServlet.valueAccumulator.initializeAllCounters();
//clear all existing in-memQueue and hidden set
boolean brokenJedis = false;
long ts1 = System.currentTimeMillis();
ShardedJedis jedis = getResource();
try {
logger.info("event=cache_filler_started queue_url=" + queueUrl + " shard=" + shard);
jedis.del(queueUrl + "-" + shard + "-Q");
jedis.del(queueUrl + "-" + shard + "-H");
jedis.del(queueUrl + "-" + shard + "-R");
String previousReceiptHandle = null;
List<CQSMessage> messages = persistenceStorage.peekQueue(queueUrl, shard, null, null, 1000);
int totalCached = 0;
while (messages.size() != 0) {
for (CQSMessage message : messages) {
addMessageToCache(queueUrl, shard, message, jedis);
totalCached++;
}
previousReceiptHandle = messages.get(messages.size() - 1).getMessageId();
messages = persistenceStorage.peekQueue(queueUrl, shard, previousReceiptHandle, null, 1000); //note: shard parameter should be in sync with receipt handle here
}
setCacheState(queueUrl, shard, QCacheState.OK, null, false);
setCacheFillerProcessing(queueUrl, shard, 0);
long ts3 = System.currentTimeMillis();
//logger.debug("event=filled_cache queue_url=" + queueUrl + " shard=" + shard +" num_cached=" + totalCached + " res_ms=" + (ts3 - ts1) + " redis_ms=" + CQSControllerServlet.valueAccumulator.getCounter(AccumulatorName.RedisTime));
logger.info("event=cache_filler_finished queue_url=" + queueUrl + " shard=" + shard +" num_cached=" + totalCached + " total_ms=" + (ts3 - ts1) + " redis_ms=" + CQSControllerServlet.valueAccumulator.getCounter(AccumulatorName.RedisTime) + " cass_ms=" + CQSControllerServlet.valueAccumulator.getCounter(AccumulatorName.CassandraTime));
} catch (Exception e) {
if (e instanceof JedisException) {
brokenJedis = true;
}
//logger.error("event=cache_filler", e);
logger.error("event=cache_filler_failed", e);
trySettingCacheState(queueUrl, shard, QCacheState.Unavailable);
} finally {
returnResource(jedis, brokenJedis);
CQSControllerServlet.valueAccumulator.deleteAllCounters();
}
}
}
/**
* Class goes through all the hidden messages for a specific queue
* and makes re-visible anything that was not deleted and has visibilityTO expired
* Note: this is a low priority thread.
*/
private class RevisibleProcessor implements Runnable {
private Logger log = Logger.getLogger(RevisibleProcessor.class);
private final String queueUrl;
private final int shard;
private boolean setAndDeleteCounters = true;
public RevisibleProcessor(String queueUrl, int shard) {
this.queueUrl = queueUrl;
this.shard = shard;
}
@Override
public void run() {
if (setAndDeleteCounters) {
CQSControllerServlet.valueAccumulator.initializeAllCounters();
}
long ts0 = System.currentTimeMillis();
QCacheState state = getCacheState(queueUrl, shard);
if (state == null || state != QCacheState.OK) {
log.debug("event=revisibility_check queue_url=" + queueUrl + " shard=" + shard +" queue_cache_state=" + (state==null?"null":state.name()) + " action=do_nothing");
return;
}
boolean brokenJedis = false;
ShardedJedis jedis = null;
List<String> memIds = new LinkedList<String>();
try {
jedis = getResource();
updateExpire(queueUrl, shard, jedis);
long ts1 = System.currentTimeMillis();
Set<String> keys = jedis.hkeys(queueUrl + "-" + shard + "-H");
long ts2 = System.currentTimeMillis();
CQSControllerServlet.valueAccumulator.addToCounter(AccumulatorName.RedisTime, (ts2 - ts1));
log.debug("event=revisibility_check queue_url=" + queueUrl + " shard=" + shard + " invisible_set_size=" + keys.size());
for (String key : keys) {
long ts3 = System.currentTimeMillis();
String val = jedis.hget(queueUrl + "-" + shard + "-H", key);
long ts4 = System.currentTimeMillis();
CQSControllerServlet.valueAccumulator.addToCounter(AccumulatorName.RedisTime, (ts4 - ts3));
if (val == null) {
continue;
}
long visibilityTo = Long.parseLong(val);
if (visibilityTo < System.currentTimeMillis()) {
memIds.add(key);
}
}
//process memIds that should be re-visible
for (String memId : memIds) {
jedis.rpush(queueUrl + "-" + shard + "-Q", memId);
jedis.hdel(queueUrl + "-" + shard + "-H", memId);
}
long ts3 = System.currentTimeMillis();
log.debug("event=revisibility_check queue_url=" + queueUrl + " shard=" + shard + " num_made_revisible=" + memIds.size() + " redisTime=" + CQSControllerServlet.valueAccumulator.getCounter(AccumulatorName.RedisTime) + " responseTimeMS=" + (ts3 - ts0) + " hidden_set_size=" + keys.size());
} catch (Exception e) {
if (e instanceof JedisException) {
brokenJedis = true;
}
log.error("event=revisibility_check", e);
} finally {
if (jedis != null) {
returnResource(jedis, brokenJedis);
}
if (setAndDeleteCounters) {
CQSControllerServlet.valueAccumulator.deleteAllCounters();
}
}
}
}
/**
* Check if the queue is in the cache and in ok state. Else kick off initialization
* and return false.
* @param queueUrl
* @param trueOnFiller returns true if the current state is Filling.
* @return true if the cache is good for use. false if it is unavailable
*/
public boolean checkCacheConsistency(String queueUrl, int shard, boolean trueOnFiller) {
try {
// check if cache's state exists, if not return false and initialize cache
// if cache's state is not OK, return false
if (redisDown.get() && System.currentTimeMillis() - lastCheckMS.longValue() <= RedisCachedCassandraPersistence.redisCheckFrequencyMS) {
return false;
}
lastCheckMS.set(System.currentTimeMillis());
QCacheState state = getCacheState(queueUrl, shard);
redisDown.set(false);
if (state == null || state == QCacheState.Unavailable) {
try {
setCacheFillerProcessing(queueUrl, shard, 20 * 60); // this must be before setCacheState or else a race-condition
setCacheState(queueUrl, shard, QCacheState.Filling, state, true);
// we successfully set the state to filling, so we queue up filling job
executor.submit(new CacheFiller(queueUrl, shard));
logger.debug("event=initialize_queue_cache cache_state=" + (state == null ? "null" : state.name()) + " queue_url=" + queueUrl + " shard=" + shard);
} catch (SetFailedException e) {
// someone beat us to it, so we return false for now and check again next time
logger.debug("event=initialize_queue_cache cache_state=" + (state == null ? "null" : state.name()) + " queue_url=" + queueUrl + " shard=" + shard);
state = getCacheState(queueUrl, shard);
if (state != null && state == QCacheState.Filling && trueOnFiller) {
return true; // otherwise continue and return false
}
}
return false;
} else if (state != QCacheState.OK) { //must be filling
// check if this is a stale filler
if (!getProcessingState(queueUrl, shard, false)) {
try {
setCacheState(queueUrl, shard, null, null, false);
logger.debug("event=clear_stale_cache_filler cache_state=" + (state == null ? "null" : state.name()) + " queue_url=" + queueUrl + " shard=" + shard);
} catch (SetFailedException e) {
logger.debug("event=clear_stale_cache_filler cache_state=" + (state == null ? "null" : state.name()) + " queue_url=" + queueUrl + " shard=" + shard);
}
}
if (trueOnFiller && state == QCacheState.Filling) {
return true;
}
return false;
}
return true;
} catch (JedisConnectionException e) {
logger.warn("event=check_cache_consistency error_code=redis_unavailable num_connections=" + numRedisConnections.get());
redisDown.set(true);
return false;
}
}
/**
* Add message to in-memory-queue. creationTS is now
* @param queueUrl
* @param message
*/
private void addMessageToCache(String queueUrl, int shard, CQSMessage message, ShardedJedis jedis) {
long ts1 = System.currentTimeMillis();
Long newLen = jedis.rpush(queueUrl + "-" + shard + "-Q", getMemQueueMessage(message.getMessageId())); //TODO: currently initialDelay is always 0
if (newLen.longValue() == 0) {
throw new IllegalStateException("Could not add memId to queue");
}
long ts2 = System.currentTimeMillis();
CQSControllerServlet.valueAccumulator.addToCounter(AccumulatorName.RedisTime, (ts2 - ts1));
}
/**
* Method tries to set cache state and swallows all exceptions that are thrown
* @param queueUrl
* @param state
*/
private void trySettingCacheState(String queueUrl, int shard, QCacheState state) {
try {
setCacheState(queueUrl, shard, state, null, false);
} catch (Exception e) {
logger.error("event=try_setting_cache_state queue_url=" + queueUrl + " shard=" + shard, e);
}
}
/**
* Update the TTL for the queue
* @param queueUrl
* @param seconds
* @param jedis
*/
private void updateExpire(String queueUrl, int shard, ShardedJedis jedis) {
int seconds = CMBProperties.getInstance().getRedisExpireTTLSec();
long ts1 = System.currentTimeMillis();
Long ret = jedis.expire(queueUrl + "-" + shard + "-Q", seconds);
if (ret == 0) {
logger.debug("event=could_not_update_expire queue_url=" + queueUrl + " shard=" + shard);
}
ret = jedis.expire(queueUrl + "-" + shard + "-H", seconds);
if (ret == 0) {
logger.debug("event=could_not_update_expire_for_hidden_set queue_url=" + queueUrl + " shard=" + shard);
}
ret = jedis.expire(queueUrl + "-" + shard + "-" + CQSConstants.REDIS_STATE, seconds);
if (ret == 0) {
throw new IllegalStateException("event=could_not_update_expire_for_state queue_url=" + queueUrl + " shard=" + shard);
}
long ts2 = System.currentTimeMillis();
CQSControllerServlet.valueAccumulator.addToCounter(AccumulatorName.RedisTime, (ts2 - ts1));
}
/**
* @return the method will always return the mem-id generated by this layer which encodes the id provided by underlying persistence layer
* Note: method updates the expire time of the queue attributes in cache.
* @throws JSONException
*/
@Override
public String sendMessage(CQSQueue queue, int shard, CQSMessage message) throws PersistenceException, IOException, InterruptedException, NoSuchAlgorithmException, JSONException {
// first persist to Cassandra and get message-id to put into cache
String messageId = persistenceStorage.sendMessage(queue, shard, message);
if (messageId == null) {
throw new IllegalStateException("Could not get id from Cassandra");
}
boolean cacheAvailable = checkCacheConsistency(queue.getRelativeUrl(), shard, true); //set in cache even if its filling
String memId = getMemQueueMessage(messageId);
boolean brokenJedis = false;
ShardedJedis jedis = null;
long ts1 = System.currentTimeMillis();
try {
if (cacheAvailable) {
int delaySeconds = 0;
if (queue.getDelaySeconds() > 0) {
delaySeconds = queue.getDelaySeconds();
}
if (message.getAttributes().containsKey(CQSConstants.DELAY_SECONDS)) {
delaySeconds = Integer.parseInt(message.getAttributes().get(CQSConstants.DELAY_SECONDS));
}
jedis = getResource();
if (delaySeconds > 0) {
jedis.zadd(queue.getRelativeUrl() + "-" + shard + "-V", System.currentTimeMillis() + (delaySeconds * 1000), memId); //insert or update already existing
} else {
jedis.rpush(queue.getRelativeUrl() + "-" + shard + "-Q", memId);
}
logger.debug("event=send_message cache_available=true msg_id= " + memId + " queue_url=" + queue.getAbsoluteUrl() + " shard=" + shard);
} else {
logger.debug("event=send_message cache_available=false msg_id= " + memId + " queue_url=" + queue.getAbsoluteUrl() + " shard=" + shard);
}
} catch (JedisConnectionException e) {
logger.error("event=send_message error_code=redis_unavailable num_connections=" + numRedisConnections.get());
brokenJedis = true;
trySettingCacheState(queue.getRelativeUrl(), shard, QCacheState.Unavailable);
} finally {
if (jedis != null) {
returnResource(jedis, brokenJedis);
}
long ts2 = System.currentTimeMillis();
CQSControllerServlet.valueAccumulator.addToCounter(AccumulatorName.RedisTime, (ts2 - ts1));
}
return memId;
}
@Override
public Map<String, String> sendMessageBatch(CQSQueue queue, int shard, List<CQSMessage> messages) throws PersistenceException, IOException, InterruptedException, NoSuchAlgorithmException, JSONException {
persistenceStorage.sendMessageBatch(queue, shard, messages);
Map<String, String> memIds = new HashMap<String, String>();
boolean cacheAvailable = checkCacheConsistency(queue.getRelativeUrl(), shard, true);//set in cache even if its filling
ShardedJedis jedis = null;
if (cacheAvailable) {
try {
jedis = getResource();
} catch (JedisConnectionException e) {
cacheAvailable = false;
trySettingCacheState(queue.getRelativeUrl(), shard, QCacheState.Unavailable);
}
}
// add messages in the same order as messages list
boolean brokenJedis = false;
try {
for (CQSMessage message : messages) {
int delaySeconds = 0;
if (queue.getDelaySeconds() > 0) {
delaySeconds = queue.getDelaySeconds();
}
if (message.getAttributes().containsKey(CQSConstants.DELAY_SECONDS)) {
delaySeconds = Integer.parseInt(message.getAttributes().get(CQSConstants.DELAY_SECONDS));
}
String clientId = message.getSuppliedMessageId();
String messageId = message.getMessageId();
String memId = getMemQueueMessage(messageId);
if (cacheAvailable) {
try {
if (delaySeconds > 0) {
jedis.zadd(queue.getRelativeUrl() + "-" + shard + "-V", System.currentTimeMillis() + (delaySeconds * 1000), memId); //insert or update already existing
} else {
jedis.rpush(queue.getRelativeUrl() + "-" + shard + "-Q", memId);
}
} catch (JedisConnectionException e) {
trySettingCacheState(queue.getRelativeUrl(), shard, QCacheState.Unavailable);
}
logger.debug("event=send_message_batch cache_available=true msg_id= " + memId + " queue_url=" + queue.getAbsoluteUrl() + " shard=" + shard);
} else {
logger.debug("event=send_message_batch cache_available=false msg_id= " + memId + " queue_url=" + queue.getAbsoluteUrl() + " shard=" + shard);
}
memIds.put(clientId, memId);
}
} catch (JedisException e) {
brokenJedis = true;
throw e;
} finally {
if (jedis != null) {
returnResource(jedis, brokenJedis);
}
}
return memIds;
}
@Override
public void deleteMessage(String queueUrl, String receiptHandle) throws PersistenceException {
String queueUrlHash = Util.getQueueUrlHashFromCache(queueUrl);
//receiptHandle is memId
String messageId = getMemQueueMessageMessageId(queueUrlHash, receiptHandle);
int shard = Util.getShardFromReceiptHandle(receiptHandle);
boolean cacheAvailable = checkCacheConsistency(queueUrl, shard, false);
if (cacheAvailable) {
ShardedJedis jedis = null;
boolean brokenJedis = false;
try {
jedis = getResource();
long ts1 = System.currentTimeMillis();
long numDeleted = jedis.hdel(queueUrl + "-" + shard + "-H", receiptHandle);
if (numDeleted != 1) {
logger.warn("event=delete_message error_code=could_not_delelete_hidden_set queue_url=" + queueUrl + " shard=" + shard + " mem_id=" + receiptHandle);
}
if (jedis.del(queueUrl + "-" + shard + "-A-" + receiptHandle) == 0) {
logger.warn("event=delete_message error_code=could_not_delete_attributes queue_url=" + queueUrl + " shard=" + shard + " mem_id=" + receiptHandle);
}
long ts2 = System.currentTimeMillis();
CQSControllerServlet.valueAccumulator.addToCounter(AccumulatorName.RedisTime, (ts2 - ts1));
} catch (JedisConnectionException e) {
logger.error("event=delete_message error_code=redis_unavailable num_connections=" + numRedisConnections.get());
brokenJedis = true;
cacheAvailable = false;
trySettingCacheState(queueUrl, shard, QCacheState.Unavailable);
} finally {
if (jedis != null) {
returnResource(jedis, brokenJedis);
}
}
}
//delete from underlying persistence layer
persistenceStorage.deleteMessage(queueUrl, messageId);
}
/**
*
* @param queue
* @param message
* @return true if message is expired, false otherwise
*/
//example of memId is: 0:0:0_0_72:2923737900040323074:-8763141905575923938
private boolean isMessageExpired(CQSQueue queue, String memId) {
if (getMemQueueMessageCreatedTS(memId) + (queue.getMsgRetentionPeriod() * 1000) < System.currentTimeMillis()) {
return true;
} else {
return false;
}
}
@Override
public List<CQSMessage> receiveMessage(CQSQueue queue, Map<String, String> receiveAttributes) throws IOException, NoSuchAlgorithmException, InterruptedException, JSONException, PersistenceException {
int shard = rand.nextInt(queue.getNumberOfShards());
int maxNumberOfMessages = 1;
int visibilityTO = queue.getVisibilityTO();
if (receiveAttributes != null && receiveAttributes.size() > 0) {
if (receiveAttributes.containsKey(CQSConstants.MAX_NUMBER_OF_MESSAGES)) {
maxNumberOfMessages = Integer.parseInt(receiveAttributes.get(CQSConstants.MAX_NUMBER_OF_MESSAGES));
}
if (receiveAttributes.containsKey(CQSConstants.VISIBILITY_TIMEOUT)) {
visibilityTO = Integer.parseInt(receiveAttributes.get(CQSConstants.VISIBILITY_TIMEOUT));
}
}
boolean cacheAvailable = checkCacheConsistency(queue.getRelativeUrl(), shard, false);
List<CQSMessage> ret = new LinkedList<CQSMessage>();
if (cacheAvailable) {
// get the messageIds from in redis list
ShardedJedis jedis = null;
boolean brokenJedis = false;
try {
jedis = getResource();
// process revisible-set before getting from queue
tryCheckAndProcessRevisibleSet(queue.getRelativeUrl(), shard, CMBProperties.getInstance().getRedisRevisibleSetFrequencySec());
try {
if (checkAndSetVisibilityProcessing(queue.getRelativeUrl(), shard, CMBProperties.getInstance().getRedisRevisibleFrequencySec())) {
logger.debug("event=scheduled_revisibility_processor");
}
} catch (SetFailedException e) {
}
boolean done = false;
while (!done) {
boolean emptyQueue = false;
HashMap<String, String> messageIdToMemId = new HashMap<String, String>();
List<String> messageIds = new LinkedList<String>();
for (int i = 0; i < maxNumberOfMessages && !emptyQueue; i++) {
long ts1 = System.currentTimeMillis();
String memId;
if (visibilityTO > 0) {
memId = jedis.lpop(queue.getRelativeUrl() + "-" + shard + "-Q");
} else {
memId = jedis.lindex(queue.getRelativeUrl() + "-" + shard + "-Q", i);
}
long ts2 = System.currentTimeMillis();
CQSControllerServlet.valueAccumulator.addToCounter(AccumulatorName.RedisTime, (ts2 - ts1));
if (memId == null || memId.equals("nil")) { //done
emptyQueue = true;
} else {
String messageId = getMemQueueMessageMessageId(queue.getRelativeUrlHash(),memId);
messageIds.add(messageId);
messageIdToMemId.put(messageId, memId);
}
}
if (messageIds.size() == 0) {
CQSMonitor.getInstance().registerEmptyResp(queue.getRelativeUrl(), 1);
return Collections.emptyList();
}
// By here messageIds have Underlying layer's messageids.
// Get messages from underlying layer. The total returned may not be what was
// in mem cache since master-master replication to Cassandra could mean other
// colo deleted the message form underlying storage.
logger.debug("event=found_msg_ids_in_redis num_mem_ids=" + messageIds.size());
try {
Map<String, CQSMessage> persisMap = persistenceStorage.getMessages(queue.getRelativeUrl(), messageIds);
for (Entry<String, CQSMessage> messageIdToMessage : persisMap.entrySet()) {
String memId = messageIdToMemId.get(messageIdToMessage.getKey());
if (memId == null) {
throw new IllegalStateException("Underlying storage layer returned a message that was not requested");
}
CQSMessage message = messageIdToMessage.getValue();
if (message == null) {
logger.warn("event=message_is_null msg_id=" + messageIdToMessage.getKey());
continue;
}
//check if message returned is expired. This will only happen if payload coming from payload-cache. Cassandra
//expires old messages just fine. If expired, skip over and continue.
if (isMessageExpired(queue, memId)) {
try {
logger.debug("event=message_expired message_id=" + memId);
persistenceStorage.deleteMessage(queue.getRelativeUrl(), message.getMessageId());
} catch (Exception e) {
//its fine to ignore this exception since message must have been auto-deleted from Cassandra
//but we need to do this to clean up payloadcache
logger.debug("event=message_already_deleted_in_cassandra msg_id=" + message.getMessageId());
}
continue;
}
//hide message if visibilityTO is greater than 0
if (visibilityTO > 0) {
long ts1 = System.currentTimeMillis();
jedis.hset(queue.getRelativeUrl() + "-" + shard + "-H", memId, Long.toString(System.currentTimeMillis() + (visibilityTO * 1000)));
long ts2 = System.currentTimeMillis();
CQSControllerServlet.valueAccumulator.addToCounter(AccumulatorName.RedisTime, (ts2 - ts1));
}
message.setMessageId(memId);
message.setReceiptHandle(memId);
//get message-attributes and populate in message
Map<String, String> msgAttrs = (message.getAttributes() != null) ? message.getAttributes() : new HashMap<String, String>();
List<String> attrs = jedis.hmget(queue.getRelativeUrl() + "-" + shard + "-A-" + memId, CQSConstants.REDIS_APPROXIMATE_FIRST_RECEIVE_TIMESTAMP, CQSConstants.REDIS_APPROXIMATE_RECEIVE_COUNT);
if (attrs.get(0) == null) {
String firstRecvTS = Long.toString(System.currentTimeMillis());
jedis.hset(queue.getRelativeUrl() + "-" + shard + "-A-" + memId, CQSConstants.REDIS_APPROXIMATE_FIRST_RECEIVE_TIMESTAMP, firstRecvTS);
msgAttrs.put(CQSConstants.APPROXIMATE_FIRST_RECEIVE_TIMESTAMP, firstRecvTS);
} else {
msgAttrs.put(CQSConstants.APPROXIMATE_FIRST_RECEIVE_TIMESTAMP, attrs.get(0));
}
int recvCount = 1;
if (attrs.get(1) != null) {
recvCount = Integer.parseInt(attrs.get(1)) + 1;
}
jedis.hset(queue.getRelativeUrl() + "-" + shard + "-A-" + memId, CQSConstants.REDIS_APPROXIMATE_RECEIVE_COUNT, Integer.toString(recvCount));
jedis.expire(queue.getRelativeUrl() + "-" + shard + "-A-" + memId, 3600 * 24 * 14); //14 days expiration if not deleted
msgAttrs.put(CQSConstants.APPROXIMATE_RECEIVE_COUNT, Integer.toString(recvCount));
message.setAttributes(msgAttrs);
ret.add(message);
}
if (ret.size() > 0) { //There may be cases where the underlying persistent message has two memIds while
//cache filling. In such cases trying to retrieve message for the second memId may result in no message
//returned. We should skip over those memIds and continue till we find at least one valid memId
done = true;
} else {
for (String messageId : messageIds) {
logger.debug("event=bad_mem_id_found msg_id=" + messageId + " action=skip_message");
}
}
} catch (HTimedOutException e1) { //If Hector timedout, push messages back
logger.error("event=hector_timeout num_messages=" + messageIds.size() + " action=pushing_messages_back_to_redis");
if (visibilityTO > 0) {
for (String messageId : messageIds) {
String memId = messageIdToMemId.get(messageId);
jedis.lpush(queue.getRelativeUrl() + "-" + shard + "-Q", memId);
}
}
throw e1;
}
}
} catch (JedisConnectionException e) {
logger.error("event=receive_message error_code=redis_unavailable num_connections=" + numRedisConnections.get());
brokenJedis = true;
trySettingCacheState(queue.getRelativeUrl(), shard, QCacheState.Unavailable);
cacheAvailable = false;
} finally {
if (jedis != null) {
returnResource(jedis, brokenJedis);
}
}
CQSMonitor.getInstance().registerCacheHit(queue.getRelativeUrl(), ret.size(), ret.size(), CacheType.QCache); //all ids from cache
logger.debug("event=messages_found cache=available num_messages=" + ret.size());
} else { //get form underlying layer
List<CQSMessage> messages = persistenceStorage.peekQueueRandom(queue.getRelativeUrl(), shard, maxNumberOfMessages);
for (CQSMessage msg : messages) {
String memId = getMemQueueMessage(msg.getMessageId()); //TODO: initialDelay is 0
msg.setMessageId(memId);
msg.setReceiptHandle(memId);
Map<String, String> msgAttrs = (msg.getAttributes() != null) ? msg.getAttributes() : new HashMap<String, String>();
msgAttrs.put(CQSConstants.APPROXIMATE_RECEIVE_COUNT, "1");
msgAttrs.put(CQSConstants.APPROXIMATE_FIRST_RECEIVE_TIMESTAMP, Long.toString(System.currentTimeMillis()));
msg.setAttributes(msgAttrs);
ret.add(msg);
}
// in this case there is no message hiding
CQSMonitor.getInstance().registerCacheHit(queue.getRelativeUrl(), 0, ret.size(), CacheType.QCache); //all ids missed cache
logger.debug("event=messages_found cache=unavailable num_messages=" + ret.size());
}
if (ret.size() == 0) {
CQSMonitor.getInstance().registerEmptyResp(queue.getRelativeUrl(), 1);
}
return ret;
}
/**
* Only hidden messages can have their visibility changed. Method updates timestamp for the memId in hidden hashtable.
* If the new visibilityTO is 0 we shortcut and make the message immediately visible.
* @return true if visibility was changed, false otherwise
*/
@Override
public boolean changeMessageVisibility(CQSQueue queue, String receiptHandle, int visibilityTO) throws PersistenceException, IOException, NoSuchAlgorithmException, InterruptedException {
int shard = Util.getShardFromReceiptHandle(receiptHandle);
boolean cacheAvailable = checkCacheConsistency(queue.getRelativeUrl(), shard, false);
if (cacheAvailable) {
ShardedJedis jedis = null;
boolean brokenJedis = false;
try {
jedis = getResource();
long ts1 = System.currentTimeMillis();
if (visibilityTO == 0) { //make immediately visible
jedis.rpush(queue.getRelativeUrl() + "-" + shard + "-Q", receiptHandle);
jedis.hdel(queue.getRelativeUrl() + "-" + shard + "-H", receiptHandle);
return true;
} else { //update new visibilityTO
jedis.hset(queue.getRelativeUrl() + "-" + shard + "-H", receiptHandle, Long.toString(System.currentTimeMillis() + (visibilityTO * 1000)));
}
long ts2 = System.currentTimeMillis();
CQSControllerServlet.valueAccumulator.addToCounter(AccumulatorName.RedisTime, (ts2 - ts1));
return true;
} catch (JedisConnectionException e) {
logger.error("event=change_message_visibility reason=redis_unavailable num_connections=" + numRedisConnections.get());
brokenJedis = true;
cacheAvailable = false;
return false;
} finally {
if (jedis != null) {
returnResource(jedis, brokenJedis);
}
}
} else {
return false;
}
}
/**
* Note: If cache is unavailable, we will return different id for a message than when the cache is available,
* so we will have duplicates in that case. Also, we currently don't respect nextReceiptHandle rather only previousReceiptHandle and length.
* @throws JSONException
*/
@Override
public List<CQSMessage> peekQueue(String queueUrl, int shard, String previousReceiptHandle, String nextReceiptHandle, int length) throws PersistenceException, IOException, NoSuchAlgorithmException, JSONException {
boolean cacheAvailable = checkCacheConsistency(queueUrl, shard, false);
if (cacheAvailable) {
List<String> memIdsRet = getIdsFromHead(queueUrl, shard, previousReceiptHandle, length);
// by here memIdsRet should have memIds to return messages for
Map<String, CQSMessage> ret = getMessages(queueUrl, memIdsRet);
// return list in the same order as memIdsRet
List<CQSMessage> messages = new LinkedList<CQSMessage>();
ShardedJedis jedis = null;
boolean brokenJedis = false;
try {
jedis = getResource();
for (String memId : memIdsRet) {
CQSMessage message = ret.get(memId);
if (message != null) {
// get message-attributes and populate in message
Map<String, String> msgAttrs = (message.getAttributes() != null) ? message.getAttributes() : new HashMap<String, String>();
List<String> attrs = jedis.hmget(queueUrl + "-" + shard + "-A-" + memId, CQSConstants.REDIS_APPROXIMATE_FIRST_RECEIVE_TIMESTAMP, CQSConstants.REDIS_APPROXIMATE_RECEIVE_COUNT);
if (attrs.get(0) != null) {
msgAttrs.put(CQSConstants.APPROXIMATE_FIRST_RECEIVE_TIMESTAMP, attrs.get(0));
}
if (attrs.get(1) != null) {
msgAttrs.put(CQSConstants.APPROXIMATE_RECEIVE_COUNT, Integer.toString(Integer.parseInt(attrs.get(1))));
}
message.setAttributes(msgAttrs);
messages.add(message);
}
}
} catch (JedisConnectionException e) {
logger.error("event=peek_message error_code=redis_unavailable num_connections=" + numRedisConnections.get());
brokenJedis = true;
cacheAvailable = false;
} finally {
if (jedis != null) {
returnResource(jedis, brokenJedis);
}
}
logger.debug("event=peek_queue cache=available queue_url=" + queueUrl + " shard=" + shard + " num_messages=" + messages.size());
return messages;
} else { //get from underlying storage
String relativeUrlHash = Util.getQueueUrlHashFromCache(queueUrl);
if (previousReceiptHandle != null) { //strip out this layer's id
previousReceiptHandle = getMemQueueMessageMessageId(relativeUrlHash, previousReceiptHandle);
}
if (nextReceiptHandle != null) {
nextReceiptHandle = getMemQueueMessageMessageId(relativeUrlHash, nextReceiptHandle);
}
List<CQSMessage> messages = persistenceStorage.peekQueue(queueUrl, shard, previousReceiptHandle, nextReceiptHandle, length);
for (CQSMessage message : messages) {
String memId = getMemQueueMessage(message.getMessageId()); //TODO: initialDelay is 0
message.setMessageId(memId);
message.setReceiptHandle(memId);
}
logger.debug("event=peek_queue cache=unavailable queue_url=" + queueUrl + " shard=" + shard + " num_messages=" + messages.size());
return messages;
}
}
@Override
public void clearQueue(String queueUrl, int shard) throws PersistenceException, NoSuchAlgorithmException, UnsupportedEncodingException {
boolean cacheAvailable = checkCacheConsistency(queueUrl, shard, true);
if (cacheAvailable) {
boolean brokenJedis = false;
ShardedJedis jedis = null;
try {
long ts1 = System.currentTimeMillis();
jedis = getResource();
Long num = jedis.del(queueUrl + "-" + shard + "-" + CQSConstants.REDIS_STATE);
logger.debug("num removed=" + num);
num = jedis.del(queueUrl + "-" + shard + "-Q");
logger.debug("num removed=" + num);
num = jedis.del(queueUrl + "-" + shard + "-H");
logger.debug("num removed=" + num);
num = jedis.del(queueUrl + "-" + shard + "-R");
logger.debug("num removed=" + num);
num = jedis.del(queueUrl + "-" + shard + "-F");
logger.debug("num removed=" + num);
num = jedis.del(queueUrl + "-" + shard + "-V");
logger.debug("num removed=" + num);
num = jedis.del(queueUrl + "-" + shard + "-VR");
logger.debug("num removed=" + num);
long ts2 = System.currentTimeMillis();
CQSControllerServlet.valueAccumulator.addToCounter(AccumulatorName.RedisTime, (ts2 - ts1));
logger.debug("event=cleared_queue queue_url=" + queueUrl + " shard=" + shard);
} catch (JedisConnectionException e) {
logger.error("event=clear_queue error_code=redis_unavailable num_connections=" + numRedisConnections.get());
brokenJedis = true;
trySettingCacheState(queueUrl, shard, QCacheState.Unavailable);
cacheAvailable = false;
} finally {
if (jedis != null) {
returnResource(jedis, brokenJedis);
}
}
}
//clear queue from underlying layer
persistenceStorage.clearQueue(queueUrl, shard);
}
@Override
public Map<String, CQSMessage> getMessages(String queueUrl, List<String> ids) throws PersistenceException, NoSuchAlgorithmException, IOException, JSONException {
//parse the ids generated by this layer to get underlying ids and get from underlying layer
List<String> messageIds = new LinkedList<String>();
HashMap<String, String> messageIdToMemId = new HashMap<String, String>();
String queueUrlHash = Util.getQueueUrlHashFromCache(queueUrl);
for (String id : ids) {
String messageId = getMemQueueMessageMessageId(queueUrlHash,id);
messageIds.add(messageId);
messageIdToMemId.put(messageId, id);
}
Map<String, CQSMessage> persisMap = persistenceStorage.getMessages(queueUrl, messageIds);
Map<String, CQSMessage> ret = new HashMap<String, CQSMessage>();
for (Entry<String, CQSMessage> idToMessage : persisMap.entrySet()) {
CQSMessage msg = idToMessage.getValue();
if (msg == null) {
continue;
}
String memId = messageIdToMemId.get(idToMessage.getKey());
msg.setMessageId(memId);
msg.setReceiptHandle(memId);
ret.put(memId, msg);
}
return ret;
}
@Override
public List<String> getIdsFromHead(String queueUrl, int shard, int num) throws PersistenceException {
return getIdsFromHead(queueUrl, shard, null, num);
}
public List<String> getIdsFromHead(String queueUrl, int shard, String previousReceiptHandle, int num) throws PersistenceException {
if (previousReceiptHandle != null && Util.getShardFromReceiptHandle(previousReceiptHandle) != shard) {
logger.warn("event=inconsistent_shard_information shard=" + shard + " receipt_handle=" + previousReceiptHandle);
}
boolean cacheAvailable = checkCacheConsistency(queueUrl, shard, true);
if (!cacheAvailable) {
return Collections.emptyList();
}
List<String> memIdsRet = new LinkedList<String>();
boolean brokenJedis = false;
ShardedJedis jedis = null;
try {
jedis = getResource();
// process re-visible set before getting from queue
tryCheckAndProcessRevisibleSet(queueUrl, shard, CMBProperties.getInstance().getRedisRevisibleSetFrequencySec());
try {
if (checkAndSetVisibilityProcessing(queueUrl, shard, CMBProperties.getInstance().getRedisRevisibleFrequencySec())) {
logger.debug("event=scheduled_revisibility_processor");
}
} catch (SetFailedException e) {
}
long llen = jedis.llen(queueUrl + "-" + shard + "-Q");
if (llen == 0L) {
return Collections.emptyList();
}
int retCount = 0;
long i = 0L;
boolean includeSet = (previousReceiptHandle == null) ? true : false;
while (retCount < num && i < llen) {
List<String> memIds = jedis.lrange(queueUrl + "-" + shard + "-Q", i, i + num - 1);
if (memIds.size() == 0) {
break; // done
}
i += num; // next time, exclude the last one in this set
for (String memId : memIds) {
if (!includeSet) {
if (memId.equals(previousReceiptHandle)) {
includeSet = true;
//skip over this one since it was the last el of the last call
}
} else {
memIdsRet.add(memId);
retCount++;
}
}
}
// by here memIdsRet should have memIds to return messages for
} catch (JedisException e) {
brokenJedis = true;
throw e;
} finally {
if (jedis != null) {
returnResource(jedis, brokenJedis);
}
}
return memIdsRet;
}
/**
*
* @param queueUrl
* @param processRevisibilitySet if true, run re-visibility processing.
* @return number of mem-ids in Redis Queue
* @throws Exception
*/
public long getQueueMessageCount(String queueUrl, boolean processHiddenIds) throws Exception {
long messageCount = 0;
CQSQueue queue = CQSCache.getCachedQueue(queueUrl);
int numberOfShards = 1;
if (queue != null) {
numberOfShards = queue.getNumberOfShards();
}
ShardedJedis jedis = null;
boolean brokenJedis = false;
try {
jedis = getResource();
for (int shard=0; shard<numberOfShards; shard++) {
boolean cacheAvailable = checkCacheConsistency(queueUrl, shard, true);
if (!cacheAvailable) {
throw new IllegalStateException("Redis cache not available");
}
if (processHiddenIds) {
checkAndSetVisibilityProcessing(queueUrl, shard, CMBProperties.getInstance().getRedisRevisibleFrequencySec());
tryCheckAndProcessRevisibleSet(queueUrl, shard, CMBProperties.getInstance().getRedisRevisibleSetFrequencySec());
}
messageCount += jedis.llen(queueUrl + "-" + shard + "-Q");
}
} catch (JedisException e) {
brokenJedis = true;
throw e;
} finally {
if (jedis != null) {
returnResource(jedis, brokenJedis);
}
}
return messageCount;
}
/**
*
* @param queueUrl
* @return number of mem-ids in Redis Queue. If Redis queue is empty, do not load from Cassandra.
* @throws Exception
*/
public long getCacheQueueMessageCount(String queueUrl) throws Exception {
long messageCount = 0;
CQSQueue queue = CQSCache.getCachedQueue(queueUrl);
int numberOfShards = 1;
if (queue != null) {
numberOfShards = queue.getNumberOfShards();
}
ShardedJedis jedis = null;
boolean brokenJedis = false;
try {
jedis = getResource();
for (int shard=0; shard<numberOfShards; shard++) {
messageCount += jedis.llen(queueUrl + "-" + shard + "-Q");
}
} catch (JedisException e) {
brokenJedis = true;
throw e;
} finally {
if (jedis != null) {
returnResource(jedis, brokenJedis);
}
}
return messageCount;
}
@Override
public long getQueueMessageCount(String queueUrl) {
long messageCount = 0;
try {
messageCount = getQueueMessageCount(queueUrl, false);
} catch (Exception ex) {
logger.error("event=failed_to_get_number_of_messages queue_url=" + queueUrl);
}
return messageCount;
}
/**
* This method get the count from redis based ont he suffix
* @param queueUrl
* @param processFlag if true, run visibility or delay clean processing.
* @return number of mem-ids in Redis Queue
* @throws Exception
*/
private long getCount(String queueUrl, String suffix, boolean processHiddenIds) throws Exception {
long messageCount = 0;
CQSQueue queue = CQSCache.getCachedQueue(queueUrl);
int numberOfShards = 1;
if (queue != null) {
numberOfShards = queue.getNumberOfShards();
}
ShardedJedis jedis = null;
boolean brokenJedis = false;
try {
jedis = getResource();
for (int shard=0; shard<numberOfShards; shard++) {
boolean cacheAvailable = checkCacheConsistency(queueUrl, shard, true);
if (!cacheAvailable) {
throw new IllegalStateException("Redis cache not available");
}
//if check for hidden message, and processFlag is true, move the message from H to Q
if(suffix.equals("-H")&&(processHiddenIds)){
checkAndSetVisibilityProcessing(queueUrl, shard, CMBProperties.getInstance().getRedisRevisibleFrequencySec());
}
//if check for delayed message, and processFlag is true, move the message from V to Q
if (suffix.equals("-V")&&(processHiddenIds)) {
tryCheckAndProcessRevisibleSet(queueUrl, shard, CMBProperties.getInstance().getRedisRevisibleSetFrequencySec());
}
//get the count number from
if(suffix.equals("-H")){
messageCount += jedis.hlen(queueUrl + "-" + shard + suffix);
} else if (suffix.equals("-V")){
messageCount += jedis.zcard(queueUrl + "-" + shard + suffix);
}
}
} catch (JedisException e) {
brokenJedis = true;
throw e;
} finally {
if (jedis != null) {
returnResource(jedis, brokenJedis);
}
}
return messageCount;
}
/**
*
* @param queueUrl
* @param visibilityProcessFlag if true, run visibility processing.
* @return number of mem-ids in Redis list
* @throws Exception
*/
public long getQueueNotVisibleMessageCount(String queueUrl, boolean visibilityProcessFlag) throws Exception {
return getCount(queueUrl, "-H", visibilityProcessFlag);
}
public long getQueueNotVisibleMessageCount(String queueUrl) {
long messageCount = 0;
try {
messageCount = getQueueNotVisibleMessageCount(queueUrl, false);
} catch (Exception ex) {
logger.error("event=failed_to_get_number_of_not_visible_messages queue_url=" + queueUrl);
}
return messageCount;
}
/**
*
* @param queueUrl
* @param visibilityProcessFlag if true, run visibility processing.
* @return number of mem-ids in Redis set for delayed messages
* @throws Exception
*/
public long getQueueDelayedMessageCount(String queueUrl, boolean visibilityProcessFlag) throws Exception {
return getCount(queueUrl, "-V", visibilityProcessFlag);
}
public long getQueueDelayedMessageCount(String queueUrl) {
long messageCount = 0;
try {
messageCount = getQueueDelayedMessageCount(queueUrl, false);
} catch (Exception ex) {
logger.error("event=failed_to_get_number_of_delayed_messages queue_url=" + queueUrl);
}
return messageCount;
}
@Override
public List<CQSMessage> peekQueueRandom(String queueUrl, int shard, int length) throws PersistenceException, IOException, NoSuchAlgorithmException, JSONException {
return persistenceStorage.peekQueueRandom(queueUrl, shard, length);
}
/**
* Get all redis shard infos
* @return list of hash maps, one for each shard
*/
public List<Map<String, String>> getInfo() {
boolean brokenJedis = false;
ShardedJedis jedis = getResource();
List<Map<String, String>> shardInfos = new ArrayList<Map<String, String>>();
try {
Collection<Jedis> shards = jedis.getAllShards();
for (Jedis shard : shards) {
String info = shard.info();
String lines[] = info.split("\n");
Map<String, String> entries = new HashMap<String, String>();
for (String line : lines) {
if (line != null && line.length() > 0) {
String keyValue[] = line.split(":");
if (keyValue.length == 2) {
entries.put(keyValue[0], keyValue[1]);
}
}
}
shardInfos.add(entries);
}
return shardInfos;
} catch (JedisException ex) {
brokenJedis = true;
throw ex;
} finally {
returnResource(jedis, brokenJedis);
}
}
/**
* Get number of redis shards
* @return number of redis shards
*/
public int getNumberOfRedisShards() {
boolean brokenJedis = false;
ShardedJedis jedis = getResource();
try {
return jedis.getAllShards().size();
} catch (JedisException ex) {
brokenJedis = true;
throw ex;
} finally {
returnResource(jedis, brokenJedis);
}
}
/**
* Clear cache across all shards. Useful for data center fail-over scenarios.
*/
public void flushAll() {
boolean brokenJedis = false;
ShardedJedis jedis = getResource();
try {
Collection<Jedis> shards = jedis.getAllShards();
for (Jedis shard : shards) {
shard.flushAll();
}
} catch (JedisException ex) {
brokenJedis = true;
throw ex;
} finally {
returnResource(jedis, brokenJedis);
}
}
public boolean isAlive() {
boolean atLeastOneShardIsUp = false;
boolean brokenJedis = false;
ShardedJedis jedis = getResource();
try {
Collection<Jedis> shards = jedis.getAllShards();
for (Jedis shard : shards) {
try {
shard.set("test", "test");
atLeastOneShardIsUp |= shard.get("test").equals("test");
} catch (JedisException ex) {
brokenJedis = true;
}
}
} catch (Exception ex) {
brokenJedis = true;
} finally {
returnResource(jedis, brokenJedis);
}
return atLeastOneShardIsUp;
}
public void shutdown () {
executor.shutdown();
revisibilityExecutor.shutdown();
}
}