zookeeper3.4.5自动清理日志

近期公司Zookeeper得log文件将系统占用快满了，查看相关文档，

从3.4.0开始，zookeeper提供了自动清理snapshot和事务日志的功能，
通过配置 autopurge.snapRetainCount 和 autopurge.purgeInterval 这两个参数能够实现定时清理了。
这两个参数都是在zoo.cfg中配置的，将其前面的注释去掉，根据需要修改日志保留个数：

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# The number of milliseconds of each tick
tickTime=2000
# The number of ticks that the initial
# synchronization phase can take
initLimit=10
# The number of ticks that can pass between
# sending a request and getting an acknowledgement
syncLimit=5
# the directory where the snapshot is stored.
dataDir=/diska/hadoop/zookeeper
# the port at which the clients will connect
clientPort=2181
server.1=dn110.104.jx:2888:3888
server.2=dn111.104.jx:2888:3888
server.3=dn112.104.jx:2888:3888

# Custom properties
autopurge.purgeInterval=1
maxClientCnxns=300
autopurge.snapRetainCount=3

autopurge.purgeInterval  
这个参数指定了清理频率，单位是小时，需要填写一个1或更大的整数，默认是0，表示不开启自己清理功能。

autopurge.snapRetainCount
这个参数和上面的参数搭配使用，这个参数指定了需要保留的文件数目。默认是保留3个。

maxClientCnxns
单个客户端与单台服务器之间的连接数的限制，是ip级别的，默认是60，如果设置为0，那么表明不作任何限制。请注意这个限制的使用范围，仅仅是单台客户端机器与单台ZK服务器之间的连接数限制，不是针对指定客户端IP，也不是ZK集群的连接数限制，也不是单台ZK对所有客户端的连接数限制。