在clickhouse集群中，经常遇到和zookeeper压力相关的问题，可以试试如下方法：

    1，建表语句设置use_minimalistic_part_header_in_zookeeper = 1，降低clickhouse在ZK上存储的数据量
    2，合理调整zk内存使用上限
    3，zoo.cfg配置文件中增加参数：(效果较为明显) 
    
         MaxSessionTimeout=120000
         forceSync=no
         autopurge.snapRetainCount=20
         autopurge.purgeInterval=48


官方的调优参数：
/etc/zookeeper/conf/zoo.cfg

# The time interval in hours for which the purge task has to be triggered.
# Set to a positive integer (1 and above) to enable the auto purging. Defaults to 0.
autopurge.purgeInterval=1
autopurge.snapRetainCount=5

## Improve Node Communication Reliability
# 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

## Reduce Snapshots
# 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=65536
# 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=10000

# The number of milliseconds of each tick
tickTime=2000
# The number of ticks that the initial
# synchronization phase can take
# This value is not quite motivated
initLimit=300
# The number of ticks that can pass between
# sending a request and getting an acknowledgement
syncLimit=10

maxClientCnxns=2000

# It is the maximum value that client may request and the server will accept.
# It is Ok to have high maxSessionTimeout on server to allow clients to work with high session timeout if they want.
# But we request session timeout of 30 seconds by default (you can change it with session_timeout_ms in ClickHouse config).
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






配置：
/etc/clickhouse-server/config.d/zookeeper.xml
<yandex>
    <zookeeper>
        <node>
            <host>example1</host>
            <port>2181</port>
        </node>
        <node>
            <host>example2</host>
            <port>2181</port>
        </node>
        <session_timeout_ms>30000</session_timeout_ms>
        <operation_timeout_ms>10000</operation_timeout_ms>
        <!-- Optional. Chroot suffix. Should exist. -->
        <root>/path/to/zookeeper/node</root>
        <!-- Optional. ZooKeeper digest ACL string. -->
        <identity>user:password</identity>
    </zookeeper>
</yandex>

/etc/clickhouse-server/preprocessed/config.xml
<!-- Allow to execute distributed DDL queries (CREATE, DROP, ALTER, RENAME) on cluster. -->
<!-- Works only if ZooKeeper is enabled. Comment it out if such functionality isn't required. -->
<distributed_ddl>
    <!-- Path in ZooKeeper to queue with DDL queries -->
    <path>/clickhouse/task_queue/ddl</path>

    <!-- Settings from this profile will be used to execute DDL queries -->
    <!-- <profile>default</profile> -->
</distributed_ddl>

参考：
https://docs.altinity.com/operationsguide/clickhouse-zookeeper/zookeeper-installation/

监控：

参考：

https://clickhouse.tech/docs/en/operations/tips/#zookeeper

https://docs.confluent.io/platform/current/zookeeper/deployment.html