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Kafka >> mail # dev >> zkclient dies after UnknownHostException in zk reconnect


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Re: zkclient dies after UnknownHostException in zk reconnect
Interesting. I haven't had the chance to dive into the zkclient codebase to
understand the root cause yet, but since you mentioned this can cause
ephemeral node loss, I am curious to know how you detected the ephemeral
node loss. Did the Kafka consumer not respond to rebalance events or did
the server not respond to state change events ? Also, ephemeral nodes are
lost only when sessions are expired on the zookeeper server or if clients
close the session actively, how does losing connection lead to ephemeral
node loss?

Thanks,
Neha
On Mon, Sep 23, 2013 at 7:02 AM, Anatoly Fayngelerin <[EMAIL PROTECTED]>wrote:

> Hi Everyone,
>
> I've run into the following issue with the Kafka server. The zkclient lib
> seems to die silently if there is an UnknownHostException(or any
> IOException) while reconnecting the ZK session. I've filed a bug about this
> with the zkclient lib(https://github.com/sgroschupf/zkclient/issues/23).
> The
> ramifications for Kafka were the silent loss of all ephemeral nodes
> associated with the affected process.
>
> Has anyone faced this issue? If so, what is the recommended way of dealing
> with this?
>
> If there is no good solution available, would the community be open to a
> patch that periodically verifies ZK connectivity?
>
> Thanks,
> Anatoly
>

 
NEW: Monitor These Apps!
elasticsearch, apache solr, apache hbase, hadoop, redis, casssandra, amazon cloudwatch, mysql, memcached, apache kafka, apache zookeeper, apache storm, ubuntu, centOS, red hat, debian, puppet labs, java, senseiDB