Update kafka properties template; disable group rebalance delay (#2471)

Author: dpkp

servers/0.11.0.0/resources/kafka.properties

@@ -4,14 +4,15 @@
 # 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.
+
 # see kafka.server.KafkaConfig for additional details and defaults
 
 ############################# Server Basics #############################
@@ -21,6 +22,12 @@ broker.id={broker_id}
 
 ############################# Socket Server Settings #############################
 
+# The address the socket server listens on. It will get the value returned from 
+# java.net.InetAddress.getCanonicalHostName() if not configured.
+#   FORMAT:
+#     listeners = listener_name://host_name:port
+#   EXAMPLE:
+#     listeners = PLAINTEXT://your.host.name:9092
 listeners={transport}://{host}:{port}
 security.inter.broker.protocol={transport}
 
@@ -38,22 +45,18 @@ allow.everyone.if.no.acl.found=true
 # The port the socket server listens on
 #port=9092
 
-# Hostname the broker will bind to. If not set, the server will bind to all interfaces
-#host.name=localhost
-
-# Hostname the broker will advertise to producers and consumers. If not set, it uses the
-# value for "host.name" if configured.  Otherwise, it will use the value returned from
-# java.net.InetAddress.getCanonicalHostName().
-#advertised.host.name=<hostname routable by clients>
+# Hostname and port the broker will advertise to producers and consumers. If not set, 
+# it uses the value for "listeners" if configured.  Otherwise, it will use the value
+# returned from java.net.InetAddress.getCanonicalHostName().
+#advertised.listeners=PLAINTEXT://your.host.name:9092
 
-# The port to publish to ZooKeeper for clients to use. If this is not set,
-# it will publish the same port that the broker binds to.
-#advertised.port=<port accessible by clients>
+# Maps listener names to security protocols, the default is for them to be the same. See the config documentation for more details
+#listener.security.protocol.map=PLAINTEXT:PLAINTEXT,SSL:SSL,SASL_PLAINTEXT:SASL_PLAINTEXT,SASL_SSL:SASL_SSL
 
-# The number of threads handling network requests
+# The number of threads that the server uses for receiving requests from the network and sending responses to the network
 num.network.threads=3
- 
-# The number of threads doing disk I/O
+
+# The number of threads that the server uses for processing requests, which may include disk I/O
 num.io.threads=8
 
 # The send buffer (SO_SNDBUF) used by the socket server
@@ -68,7 +71,7 @@ socket.request.max.bytes=104857600
 
 ############################# Log Basics #############################
 
-# A comma seperated list of directories under which to store log files
+# A comma separated list of directories under which to store log files
 log.dirs={tmp_dir}/data
 
 # The default number of log partitions per topic. More partitions allow greater
@@ -81,14 +84,25 @@ default.replication.factor={replicas}
 replica.lag.time.max.ms=1000
 replica.socket.timeout.ms=1000
 
+# The number of threads per data directory to be used for log recovery at startup and flushing at shutdown.
+# This value is recommended to be increased for installations with data dirs located in RAID array.
+num.recovery.threads.per.data.dir=1
+
+############################# Internal Topic Settings  #############################
+# The replication factor for the group metadata internal topics "__consumer_offsets" and "__transaction_state"
+# For anything other than development testing, a value greater than 1 is recommended to ensure availability such as 3.
+offsets.topic.replication.factor=1
+transaction.state.log.replication.factor=1
+transaction.state.log.min.isr=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 excessive 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.
 
@@ -105,17 +119,17 @@ replica.socket.timeout.ms=1000
 # A segment will be deleted whenever *either* of these criteria are met. Deletion always happens
 # from the end of the log.
 
-# The minimum age of a log file to be eligible for deletion
+# The minimum age of a log file to be eligible for deletion due to age
 log.retention.hours=168
 
-# A size-based retention policy for logs. Segments are pruned from the log as long as the remaining
-# segments don't drop below log.retention.bytes.
+# A size-based retention policy for logs. Segments are pruned from the log unless the remaining
+# segments drop below log.retention.bytes. Functions independently of log.retention.hours.
 #log.retention.bytes=1073741824
 
 # 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
 
@@ -145,3 +159,13 @@ zookeeper.connect={zk_host}:{zk_port}/{zk_chroot}
 zookeeper.connection.timeout.ms=30000
 # We want to expire kafka broker sessions quickly when brokers die b/c we restart them quickly
 zookeeper.session.timeout.ms=500
+
+
+############################# Group Coordinator Settings #############################
+
+# The following configuration specifies the time, in milliseconds, that the GroupCoordinator will delay the initial consumer rebalance.
+# The rebalance will be further delayed by the value of group.initial.rebalance.delay.ms as new members join the group, up to a maximum of max.poll.interval.ms.
+# The default value for this is 3 seconds.
+# We override this to 0 here as it makes for a better out-of-the-box experience for development and testing.
+# However, in production environments the default value of 3 seconds is more suitable as this will help to avoid unnecessary, and potentially expensive, rebalances during application startup.
+group.initial.rebalance.delay.ms=0

servers/0.11.0.1/resources/kafka.properties

@@ -4,14 +4,15 @@
 # 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.
+
 # see kafka.server.KafkaConfig for additional details and defaults
 
 ############################# Server Basics #############################
@@ -21,6 +22,12 @@ broker.id={broker_id}
 
 ############################# Socket Server Settings #############################
 
+# The address the socket server listens on. It will get the value returned from 
+# java.net.InetAddress.getCanonicalHostName() if not configured.
+#   FORMAT:
+#     listeners = listener_name://host_name:port
+#   EXAMPLE:
+#     listeners = PLAINTEXT://your.host.name:9092
 listeners={transport}://{host}:{port}
 security.inter.broker.protocol={transport}
 
@@ -38,22 +45,18 @@ allow.everyone.if.no.acl.found=true
 # The port the socket server listens on
 #port=9092
 
-# Hostname the broker will bind to. If not set, the server will bind to all interfaces
-#host.name=localhost
-
-# Hostname the broker will advertise to producers and consumers. If not set, it uses the
-# value for "host.name" if configured.  Otherwise, it will use the value returned from
-# java.net.InetAddress.getCanonicalHostName().
-#advertised.host.name=<hostname routable by clients>
+# Hostname and port the broker will advertise to producers and consumers. If not set, 
+# it uses the value for "listeners" if configured.  Otherwise, it will use the value
+# returned from java.net.InetAddress.getCanonicalHostName().
+#advertised.listeners=PLAINTEXT://your.host.name:9092
 
-# The port to publish to ZooKeeper for clients to use. If this is not set,
-# it will publish the same port that the broker binds to.
-#advertised.port=<port accessible by clients>
+# Maps listener names to security protocols, the default is for them to be the same. See the config documentation for more details
+#listener.security.protocol.map=PLAINTEXT:PLAINTEXT,SSL:SSL,SASL_PLAINTEXT:SASL_PLAINTEXT,SASL_SSL:SASL_SSL
 
-# The number of threads handling network requests
+# The number of threads that the server uses for receiving requests from the network and sending responses to the network
 num.network.threads=3
- 
-# The number of threads doing disk I/O
+
+# The number of threads that the server uses for processing requests, which may include disk I/O
 num.io.threads=8
 
 # The send buffer (SO_SNDBUF) used by the socket server
@@ -68,7 +71,7 @@ socket.request.max.bytes=104857600
 
 ############################# Log Basics #############################
 
-# A comma seperated list of directories under which to store log files
+# A comma separated list of directories under which to store log files
 log.dirs={tmp_dir}/data
 
 # The default number of log partitions per topic. More partitions allow greater
@@ -81,14 +84,25 @@ default.replication.factor={replicas}
 replica.lag.time.max.ms=1000
 replica.socket.timeout.ms=1000
 
+# The number of threads per data directory to be used for log recovery at startup and flushing at shutdown.
+# This value is recommended to be increased for installations with data dirs located in RAID array.
+num.recovery.threads.per.data.dir=1
+
+############################# Internal Topic Settings  #############################
+# The replication factor for the group metadata internal topics "__consumer_offsets" and "__transaction_state"
+# For anything other than development testing, a value greater than 1 is recommended to ensure availability such as 3.
+offsets.topic.replication.factor=1
+transaction.state.log.replication.factor=1
+transaction.state.log.min.isr=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 excessive 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.
 
@@ -105,17 +119,17 @@ replica.socket.timeout.ms=1000
 # A segment will be deleted whenever *either* of these criteria are met. Deletion always happens
 # from the end of the log.
 
-# The minimum age of a log file to be eligible for deletion
+# The minimum age of a log file to be eligible for deletion due to age
 log.retention.hours=168
 
-# A size-based retention policy for logs. Segments are pruned from the log as long as the remaining
-# segments don't drop below log.retention.bytes.
+# A size-based retention policy for logs. Segments are pruned from the log unless the remaining
+# segments drop below log.retention.bytes. Functions independently of log.retention.hours.
 #log.retention.bytes=1073741824
 
 # 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
 
@@ -145,3 +159,13 @@ zookeeper.connect={zk_host}:{zk_port}/{zk_chroot}
 zookeeper.connection.timeout.ms=30000
 # We want to expire kafka broker sessions quickly when brokers die b/c we restart them quickly
 zookeeper.session.timeout.ms=500
+
+
+############################# Group Coordinator Settings #############################
+
+# The following configuration specifies the time, in milliseconds, that the GroupCoordinator will delay the initial consumer rebalance.
+# The rebalance will be further delayed by the value of group.initial.rebalance.delay.ms as new members join the group, up to a maximum of max.poll.interval.ms.
+# The default value for this is 3 seconds.
+# We override this to 0 here as it makes for a better out-of-the-box experience for development and testing.
+# However, in production environments the default value of 3 seconds is more suitable as this will help to avoid unnecessary, and potentially expensive, rebalances during application startup.
+group.initial.rebalance.delay.ms=0