do apps with producers have to be restarted if cluster goes down and comes back up?

[S Ahmed <sa...@gmail.com>]

Hi,

A few questions on timing related issues when certain parts of kafka go
down.

1.  If zookeeper goes down, then I bring it back online, do I have to
restart the brokers?
2.  If the brokers go down, producers will be erroring out.  When the
brokers are back online, do I have to restart the processes with producers?

3. When servers are restarted, how can you gaurantee that first the
zookeeper server come online, THEN the brokers, and THEN the webapp's with
the producers?   Or is the timing not that strict because of e.g. timeout
re-connect durations?

Thanks.

Re: do apps with producers have to be restarted if cluster goes down and comes back up?

[Neha Narkhede <ne...@gmail.com>]

1.  If zookeeper goes down, then I bring it back online, do I have to
restart the brokers?

You shouldn't have to restart the brokers if the broker side config "
zookeeper.connection.timeout.ms" is tuned such that zookeeper is brought
back online within the configured timeout.

2.  If the brokers go down, producers will be erroring out.  When the
brokers are back online, do I have to restart the processes with producers?

This depends on the number of retries configured on the producer. For the
new producer, this config is "retries".

3. When servers are restarted, how can you gaurantee that first the
zookeeper server come online, THEN the brokers, and THEN the webapp's with
the producers?   Or is the timing not that strict because of e.g. timeout
re-connect durations?

Ideally, there shouldn't be a timing issue if the config is right. However,
if you do see an issue, please report it.

Thanks,
Neha


On Thu, Jun 26, 2014 at 7:36 AM, S Ahmed <sa...@gmail.com> wrote:

> Hi,
>
> A few questions on timing related issues when certain parts of kafka go
> down.
>
> 1.  If zookeeper goes down, then I bring it back online, do I have to
> restart the brokers?
> 2.  If the brokers go down, producers will be erroring out.  When the
> brokers are back online, do I have to restart the processes with producers?
>
> 3. When servers are restarted, how can you gaurantee that first the
> zookeeper server come online, THEN the brokers, and THEN the webapp's with
> the producers?   Or is the timing not that strict because of e.g. timeout
> re-connect durations?
>
> Thanks.
>