Added example parameters for ZooKeeper to documentation [#CLICKHOUSE-3].

doc/administration/zookeeper.md

@@ -0,0 +1,138 @@
+As of 2017-05-20, we have the following configuration in production:
+
+ZooKeeper version is 3.5.1.
+
+zoo.cfg:
+
+```
+# http://hadoop.apache.org/zookeeper/docs/current/zookeeperAdmin.html
+
+# The number of milliseconds of each tick
+tickTime=2000
+# The number of ticks that the initial
+# synchronization phase can take
+initLimit=30000
+# The number of ticks that can pass between
+# sending a request and getting an acknowledgement
+syncLimit=10
+
+maxClientCnxns=2000
+
+maxSessionTimeout=60000000
+# the directory where the snapshot is stored.
+dataDir=/opt/zookeeper/{{ cluster['name'] }}/data
+# Place the dataLogDir to a separate physical disc for better performance
+dataLogDir=/opt/zookeeper/{{ cluster['name'] }}/logs
+
+autopurge.snapRetainCount=10
+autopurge.purgeInterval=1
+
+
+# To avoid seeks ZooKeeper allocates space in the transaction log file in
+# blocks of preAllocSize kilobytes. The default block size is 64M. One reason
+# for changing the size of the blocks is to reduce the block size if snapshots
+# are taken more often. (Also, see snapCount).
+preAllocSize=131072
+
+# Clients can submit requests faster than ZooKeeper can process them,
+# especially if there are a lot of clients. To prevent ZooKeeper from running
+# out of memory due to queued requests, ZooKeeper will throttle clients so that
+# there is no more than globalOutstandingLimit outstanding requests in the
+# system. The default limit is 1,000.ZooKeeper logs transactions to a
+# transaction log. After snapCount transactions are written to a log file a
+# snapshot is started and a new transaction log file is started. The default
+# snapCount is 10,000.
+snapCount=3000000
+
+# If this option is defined, requests will be will logged to a trace file named
+# traceFile.year.month.day.
+#traceFile=
+
+# Leader accepts client connections. Default value is "yes". The leader machine
+# coordinates updates. For higher update throughput at thes slight expense of
+# read throughput the leader can be configured to not accept clients and focus
+# on coordination.
+leaderServes=yes
+
+standaloneEnabled=false
+dynamicConfigFile=/etc/zookeeper-{{ cluster['name'] }}/conf/zoo.cfg.dynamic
+```
+
+Java version:
+
+```
+Java(TM) SE Runtime Environment (build 1.8.0_25-b17)
+Java HotSpot(TM) 64-Bit Server VM (build 25.25-b02, mixed mode)
+```
+
+Java parameters:
+
+```
+NAME=zookeeper-{{ cluster['name'] }}
+ZOOCFGDIR=/etc/$NAME/conf
+
+# TODO this is really ugly
+# How to find out, which jars are needed?
+# seems, that log4j requires the log4j.properties file to be in the classpath
+CLASSPATH="$ZOOCFGDIR:/usr/build/classes:/usr/build/lib/*.jar:/usr/share/zookeeper/zookeeper-3.5.1-metrika.jar:/usr/share/zookeeper/slf4j-log4j12-1.7.5.jar:/usr/share/zookeeper/slf4j-api-1.7.5.jar:/usr/share/zookeeper/servlet-api-2.5-20081211.jar:/usr/share/zookeeper/netty-3.7.0.Final.jar:/usr/share/zookeeper/log4j-1.2.16.jar:/usr/share/zookeeper/jline-2.11.jar:/usr/share/zookeeper/jetty-util-6.1.26.jar:/usr/share/zookeeper/jetty-6.1.26.jar:/usr/share/zookeeper/javacc.jar:/usr/share/zookeeper/jackson-mapper-asl-1.9.11.jar:/usr/share/zookeeper/jackson-core-asl-1.9.11.jar:/usr/share/zookeeper/commons-cli-1.2.jar:/usr/src/java/lib/*.jar:/usr/etc/zookeeper"
+
+ZOOCFG="$ZOOCFGDIR/zoo.cfg"
+ZOO_LOG_DIR=/var/log/$NAME
+USER=zookeeper
+GROUP=zookeeper
+PIDDIR=/var/run/$NAME
+PIDFILE=$PIDDIR/$NAME.pid
+SCRIPTNAME=/etc/init.d/$NAME
+JAVA=/usr/bin/java
+ZOOMAIN="org.apache.zookeeper.server.quorum.QuorumPeerMain"
+ZOO_LOG4J_PROP="INFO,ROLLINGFILE"
+JMXLOCALONLY=false
+JAVA_OPTS="-Xms{{ cluster.get('xms','128M') }} \
+    -Xmx{{ cluster.get('xmx','1G') }} \
+    -Xloggc:/var/log/$NAME/zookeeper-gc.log \
+    -XX:+UseGCLogFileRotation \
+    -XX:NumberOfGCLogFiles=16 \
+    -XX:GCLogFileSize=16M \
+    -verbose:gc \
+    -XX:+PrintGCTimeStamps \
+    -XX:+PrintGCDateStamps \
+    -XX:+PrintGCDetails
+    -XX:+PrintTenuringDistribution \
+    -XX:+PrintGCApplicationStoppedTime \
+    -XX:+PrintGCApplicationConcurrentTime \
+    -XX:+PrintSafepointStatistics \
+    -XX:+UseParNewGC \
+    -XX:+UseConcMarkSweepGC \
+-XX:+CMSParallelRemarkEnabled"
+```
+
+Salt init:
+
+```
+description "zookeeper-{{ cluster['name'] }} centralized coordination service"
+
+start on runlevel [2345]
+stop on runlevel [!2345]
+
+respawn
+
+limit nofile 8192 8192
+
+pre-start script
+    [ -r "/etc/zookeeper-{{ cluster['name'] }}/conf/environment" ] || exit 0
+    . /etc/zookeeper-{{ cluster['name'] }}/conf/environment
+    [ -d $ZOO_LOG_DIR ] || mkdir -p $ZOO_LOG_DIR
+    chown $USER:$GROUP $ZOO_LOG_DIR
+end script
+
+script
+    . /etc/zookeeper-{{ cluster['name'] }}/conf/environment
+    [ -r /etc/default/zookeeper ] && . /etc/default/zookeeper
+    if [ -z "$JMXDISABLE" ]; then
+        JAVA_OPTS="$JAVA_OPTS -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.local.only=$JMXLOCALONLY"
+    fi
+    exec start-stop-daemon --start -c $USER --exec $JAVA --name zookeeper-{{ cluster['name'] }} \
+        -- -cp $CLASSPATH $JAVA_OPTS -Dzookeeper.log.dir=${ZOO_LOG_DIR} \
+        -Dzookeeper.root.logger=${ZOO_LOG4J_PROP} $ZOOMAIN $ZOOCFG
+end script
+```