hbase GC造成数据处理延迟(GC pool)

时间压测过程中，通过程序加时间戳判断，在批量查询hbase的时候，会有部分数据查询时间大于8s，这肯定是不能接受的，查看hbase的日志发现原因,有类似日志'GC pool',推测是GC问题，各种查询资料：

...
2018-03-01 17:32:16,243 WARN org.apache.hadoop.hbase.util.JvmPauseMonitor: Detected pause in JVM or host machine (eg GC): pause of approximately 16100ms
GC pool 'ParNew' had collection(s): count=1 time=0ms
GC pool 'ConcurrentMarkSweep' had collection(s): count=1 time=8791ms

...........

解决：

参考<>这本书JVM GC调优解决，在配置文件下面设置GC策略，增大内存，解决了此问题。

 

# Configure PermSize. Only needed in JDK7. You can safely remove it for JDK8+
#export HBASE_MASTER_OPTS="$HBASE_MASTER_OPTS -XX:PermSize=128m -XX:MaxPermSize=512m"
#export HBASE_REGIONSERVER_OPTS="$HBASE_REGIONSERVER_OPTS -XX:PermSize=256m -XX:MaxPermSize=256m"
#export HBASE_MASTER_OPTS="$HBASE_MASTER_OPTS -Xmx512m"
#export HBASE_REGIONSERVER_OPTS="$HBASE_REGIONSERVER_OPTS -Xmx512m"

 

# export HBASE_JMX_BASE="-Dcom.sun.management.jmxremote.ssl=false -Dcom.sun.management.jmxremote.authenticate=false"
# export HBASE_MASTER_OPTS="$HBASE_MASTER_OPTS $HBASE_JMX_BASE -Dcom.sun.management.jmxremote.port=10101"
# export HBASE_REGIONSERVER_OPTS="$HBASE_REGIONSERVER_OPTS $HBASE_JMX_BASE -Dcom.sun.management.jmxremote.port=10102"
# export HBASE_THRIFT_OPTS="$HBASE_THRIFT_OPTS $HBASE_JMX_BASE -Dcom.sun.management.jmxremote.port=10103"
# export HBASE_ZOOKEEPER_OPTS="$HBASE_ZOOKEEPER_OPTS $HBASE_JMX_BASE -Dcom.sun.management.jmxremote.port=10104"
# export HBASE_REST_OPTS="$HBASE_REST_OPTS $HBASE_JMX_BASE -Dcom.sun.management.jmxremote.port=10105"

# File naming hosts on which HRegionServers will run.  $HBASE_HOME/conf/regionservers by default.
# export HBASE_REGIONSERVERS=${HBASE_HOME}/conf/regionservers

# Uncomment and adjust to keep all the Region Server pages mapped to be memory resident
#HBASE_REGIONSERVER_MLOCK=true
#HBASE_REGIONSERVER_UID="hbase"

# File naming hosts on which backup HMaster will run.  $HBASE_HOME/conf/backup-masters by default.
# export HBASE_BACKUP_MASTERS=${HBASE_HOME}/conf/backup-masters

# Extra ssh options.  Empty by default.
# export HBASE_SSH_OPTS="-o ConnectTimeout=1 -o SendEnv=HBASE_CONF_DIR"

# Where log files are stored.  $HBASE_HOME/logs by default.
# export HBASE_LOG_DIR=${HBASE_HOME}/logs

# Enable remote JDWP debugging of major HBase processes. Meant for Core Developers 
# export HBASE_MASTER_OPTS="$HBASE_MASTER_OPTS -Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=8070"
# export HBASE_REGIONSERVER_OPTS="$HBASE_REGIONSERVER_OPTS -Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=8071"
# export HBASE_THRIFT_OPTS="$HBASE_THRIFT_OPTS -Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=8072"
# export HBASE_ZOOKEEPER_OPTS="$HBASE_ZOOKEEPER_OPTS -Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=8073"

# A string representing this instance of hbase. $USER by default.
# export HBASE_IDENT_STRING=$USER

# The scheduling priority for daemon processes.  See 'man nice'.
# export HBASE_NICENESS=10

# The directory where pid files are stored. /tmp by default.
# export HBASE_PID_DIR=/var/hadoop/pids

# Seconds to sleep between slave commands.  Unset by default.  This
# can be useful in large clusters, where, e.g., slave rsyncs can
# otherwise arrive faster than the master can service them.
# export HBASE_SLAVE_SLEEP=0.1

# Tell HBase whether it should manage it's own instance of Zookeeper or not.
# export HBASE_MANAGES_ZK=true

# The default log rolling policy is RFA, where the log file is rolled as per the size defined for the 
# RFA appender. Please refer to the log4j.properties file to see more details on this appender.
# In case one needs to do log rolling on a date change, one should set the environment property
# HBASE_ROOT_LOGGER to ",DRFA".
# For example:
# HBASE_ROOT_LOGGER=INFO,DRFA
# The reason for changing default to RFA is to avoid the boundary case of filling out disk space as 
# DRFA doesn't put any cap on the log size. Please refer to HBase-5655 for more context.

export JAVA_HOME=/java/jdk
export HBASE_MANAGES_ZK=false
 

也可以参考：https://blog.csdn.net/xiefu5hh/article/details/53090725