zookeeper-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Raúl Gutiérrez Segalés <...@itevenworks.net>
Subject Re: Regarding large number of watch count
Date Tue, 29 Apr 2014 17:00:28 GMT
Hi,


On 29 April 2014 01:30, Jung Young Seok <jung.youngseok@gmail.com> wrote:

> Dear Zookeeper-user,
>
> We have 3 zookeeper node clustered.
> The zookeeper is used as application lock coordinator.
> Client creates node(key) when it needs lock then release and delete the
> node(key) when the usage is done.
>
> Strangely, zk_watch_count has been increased.
> In case of leader, zk_watch_count reached 6804.
>
> ==================================================================
> Detailed information is below. (mntr)
>
> 1. Zoo-1 (Follower)
> Status Information: OK Zookeeper State : follower zk_avg_latency 2
> zk_max_latency 215 zk_min_latency 0 zk_packets_received 9001127
> zk_packets_sent 9027569 zk_num_alive_connections 3 zk_outstanding_requests
> 0 zk_server_state follower zk_znode_count 12 zk_watch_count 1786
> zk_ephemerals_count 2 zk_approximate_data_size 525
> zk_open_file_descriptor_count 29 zk_max_file_descriptor_count 4096
> Performance Data: zk_version 3.4.6-1569965, built on 02/20/2014 09:09 GMT
> 2. Zoo-2 (Follower)
> Status Information: OK Zookeeper State : follower zk_avg_latency 0
> zk_max_latency 6 zk_min_latency 0 zk_packets_received 3539 zk_packets_sent
> 3538 zk_num_alive_connections 2 zk_outstanding_requests 0 zk_server_state
> follower zk_znode_count 12 zk_watch_count 0 zk_ephemerals_count 2
> zk_approximate_data_size 525 zk_open_file_descriptor_count 28
> zk_max_file_descriptor_count 4096 Performance Data: zk_version
> 3.4.6-1569965, built on 02/20/2014 09:09 GMT
> 3. Zoo-3 (Leader) Status Information: OK Zookeeper State : leader
> zk_avg_latency 1 zk_max_latency 214 zk_min_latency 0 zk_packets_received
> 21575604 zk_packets_sent 21638420 zk_num_alive_connections 4
> zk_outstanding_requests 0 zk_server_state leader zk_znode_count 18
> zk_watch_count 6804 zk_ephemerals_count 5 zk_approximate_data_size 954
> zk_open_file_descriptor_count 32 zk_max_file_descriptor_count 4096
> zk_followers 2 zk_synced_followers 2 zk_pending_syncs 0 Performance Data:
> zk_version 3.4.6-1569965, built on 02/20/2014 09:09 GMT
>
> ==================================================================
>
> My questions are,
> 1. Is it normal case that zk_watch_count reached 6804?
>
> 2. Why has zk_watch_count been increased?
> - We use tomcat + Apache Curator + Zookeeper 3.4.6
>
> 3. Would it make trouble if zk_watch_count reach too large number?
>
> 4. Is there any way that I can reduce the zk_watch_count?
>
>
You can introspect the watches via wchs (summary), wchc (watches by
session) and wchp (watches by path). That'll give you an idea of what's
going on. For example, on one of my servers:

$ echo wchp | nc localhost 2181
/messaging/00/0019/L2383
        0x45aa3508a3ab77
        0x45aa35089f8dce
        0x45aa3508a2837d
/search/member_0000283539
        0x145aa2cc2b345d7
/messaging/00/0019/L2384
        0x45aa35089f8de4
...


-rgs

Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message