KAFKA-2988; Change default configuration of the log cleaner

Author: Grant Henke <granthenke@gmail.com> Reviewers: Ismael Juma <ismael@juma.me.uk>, Jun Rao <junrao@gmail.com> Closes apache#686 from granthenke/compaction
dtn97 · Jan 7, 2016 · ee1770e · ee1770e
1 parent a9ff3f2
commit ee1770e
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Showing 4 changed files with 13 additions and 15 deletions.
diff --git a/config/server.properties b/config/server.properties
@@ -4,9 +4,9 @@
 # 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.
@@ -40,7 +40,7 @@ listeners=PLAINTEXT://:9092
 
 # The number of threads handling network requests
 num.network.threads=3
- 
+
 # The number of threads doing disk I/O
 num.io.threads=8
 
@@ -71,11 +71,11 @@ num.recovery.threads.per.data.dir=1
 ############################# Log Flush Policy #############################
 
 # Messages are immediately written to the filesystem but by default we only fsync() to sync
-# the OS cache lazily. The following configurations control the flush of data to disk. 
+# the OS cache lazily. The following configurations control the flush of data to disk.
 # There are a few important trade-offs here:
 #    1. Durability: Unflushed data may be lost if you are not using replication.
 #    2. Latency: Very large flush intervals may lead to latency spikes when the flush does occur as there will be a lot of data to flush.
-#    3. Throughput: The flush is generally the most expensive operation, and a small flush interval may lead to exceessive seeks. 
+#    3. Throughput: The flush is generally the most expensive operation, and a small flush interval may lead to exceessive seeks.
 # The settings below allow one to configure the flush policy to flush data after a period of time or
 # every N messages (or both). This can be done globally and overridden on a per-topic basis.
 
@@ -102,14 +102,10 @@ log.retention.hours=168
 # The maximum size of a log segment file. When this size is reached a new log segment will be created.
 log.segment.bytes=1073741824
 
-# The interval at which log segments are checked to see if they can be deleted according 
+# The interval at which log segments are checked to see if they can be deleted according
 # to the retention policies
 log.retention.check.interval.ms=300000
 
-# By default the log cleaner is disabled and the log retention policy will default to just delete segments after their retention expires.
-# If log.cleaner.enable=true is set the cleaner will be enabled and individual logs can then be marked for log compaction.
-log.cleaner.enable=false
-
 ############################# Zookeeper #############################
 
 # Zookeeper connection string (see zookeeper docs for details).

diff --git a/core/src/main/scala/kafka/server/KafkaConfig.scala b/core/src/main/scala/kafka/server/KafkaConfig.scala
@@ -79,12 +79,12 @@ object Defaults {
   val LogCleanupPolicy = Delete
   val LogCleanerThreads = 1
   val LogCleanerIoMaxBytesPerSecond = Double.MaxValue
-  val LogCleanerDedupeBufferSize = 500 * 1024 * 1024L
+  val LogCleanerDedupeBufferSize = 128 * 1024 * 1024L
   val LogCleanerIoBufferSize = 512 * 1024
   val LogCleanerDedupeBufferLoadFactor = 0.9d
   val LogCleanerBackoffMs = 15 * 1000
   val LogCleanerMinCleanRatio = 0.5d
-  val LogCleanerEnable = false
+  val LogCleanerEnable = true
   val LogCleanerDeleteRetentionMs = 24 * 60 * 60 * 1000L
   val LogIndexSizeMaxBytes = 10 * 1024 * 1024
   val LogIndexIntervalBytes = 4096
@@ -401,7 +401,7 @@ object KafkaConfig {
   "will allow more log to be cleaned at once but will lead to more hash collisions"
   val LogCleanerBackoffMsDoc = "The amount of time to sleep when there are no logs to clean"
   val LogCleanerMinCleanRatioDoc = "The minimum ratio of dirty log to total log for a log to eligible for cleaning"
-  val LogCleanerEnableDoc = "Should we enable log cleaning?"
+  val LogCleanerEnableDoc = "Enable the log cleaner process to run on the server? Should be enabled if using any topics with a cleanup.policy=compact including the internal offsets topic. If disabled those topics will not be compacted and continually grow in size."
   val LogCleanerDeleteRetentionMsDoc = "How long are delete records retained?"
   val LogIndexSizeMaxBytesDoc = "The maximum size in bytes of the offset index"
   val LogIndexIntervalBytesDoc = "The interval with which we add an entry to the offset index"

diff --git a/core/src/test/scala/unit/kafka/utils/TestUtils.scala b/core/src/test/scala/unit/kafka/utils/TestUtils.scala
@@ -104,7 +104,7 @@ object TestUtils extends Logging {
     })
     f
   }
-  
+
   /**
    * Create a random log directory in the format <string>-<int> used for Kafka partition logs.
    * It is the responsibility of the caller to set up a shutdown hook for deletion of the directory.
@@ -213,6 +213,7 @@ object TestUtils extends Logging {
     props.put("controlled.shutdown.enable", enableControlledShutdown.toString)
     props.put("delete.topic.enable", enableDeleteTopic.toString)
     props.put("controlled.shutdown.retry.backoff.ms", "100")
+    props.put("log.cleaner.dedupe.buffer.size", "2097152")
 
     if (protocolAndPorts.exists { case (protocol, _) => usesSslTransportLayer(protocol) })
       props.putAll(sslConfigs(Mode.SERVER, false, trustStoreFile, s"server$nodeId"))
@@ -470,7 +471,7 @@ object TestUtils extends Logging {
     producerProps.put(ProducerConfig.MAX_BLOCK_MS_CONFIG, maxBlockMs.toString)
     producerProps.put(ProducerConfig.BUFFER_MEMORY_CONFIG, bufferSize.toString)
     producerProps.put(ProducerConfig.RETRIES_CONFIG, retries.toString)
-        
+
     /* Only use these if not already set */
     val defaultProps = Map(
       ProducerConfig.RETRY_BACKOFF_MS_CONFIG -> "100",

diff --git a/docs/upgrade.html b/docs/upgrade.html
@@ -39,6 +39,7 @@ <h5><a id="upgrade_9_breaking" href="#upgrade_9_breaking">Potential breaking cha
     <li> Broker IDs above 1000 are now reserved by default to automatically assigned broker IDs. If your cluster has existing broker IDs above that threshold make sure to increase the reserved.broker.max.id broker configuration property accordingly. </li>
     <li> Configuration parameter replica.lag.max.messages was removed. Partition leaders will no longer consider the number of lagging messages when deciding which replicas are in sync. </li>
     <li> Configuration parameter replica.lag.time.max.ms now refers not just to the time passed since last fetch request from replica, but also to time since the replica last caught up. Replicas that are still fetching messages from leaders but did not catch up to the latest messages in replica.lag.time.max.ms will be considered out of sync. </li>
+    <li> Configuration parameter log.cleaner.enable is now true by default. This means topics with a cleanup.policy=compact will now be compacted by default, and 128 MB of heap will be allocated to the cleaner process via log.cleaner.dedupe.buffer.size. You may want to review log.cleaner.dedupe.buffer.size and the other log.cleaner configuration values based on your usage of compacted topics. </li>
     <li> MirrorMaker no longer supports multiple target clusters. As a result it will only accept a single --consumer.config parameter. To mirror multiple source clusters, you will need at least one MirrorMaker instance per source cluster, each with its own consumer configuration. </li>
     <li> Tools packaged under <em>org.apache.kafka.clients.tools.*</em> have been moved to <em>org.apache.kafka.tools.*</em>. All included scripts will still function as usual, only custom code directly importing these classes will be affected. </li>
     <li> The default Kafka JVM performance options (KAFKA_JVM_PERFORMANCE_OPTS) have been changed in kafka-run-class.sh. </li>