curator-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Cameron McKenzie <cammcken...@apache.org>
Subject Re: Query on SESSION_LOST (3.0.0)
Date Wed, 18 Nov 2015 21:16:00 GMT
Hey Vikrant,
The issue was that the LOST event was being published by Curator when it
gave up trying to reconnect to Zookeeper after connection loss, whereas
most people were interpreting it to mean that the session was lost.

So, the change in CURATOR-3.0 is that the LOST event will be published when
the session has either expired and Curator is explicitly told this by
Zookeeper (implying that a connection is present), or when Curator has been
disconnected from Zookeeper for long enough for the session to have expired
on the server (this will occur when no connection to Zookeeper is present).

So, I'm not sure how it will help your case. It is just a more reliable way
of knowing that the session is gone and all related ephemeral state on the
Zookeeper server will also be gone.

Note that it's also possible to tell Curator to use the legacy way of
interpreting the LOST event.
cheers


On Thu, Nov 19, 2015 at 8:09 AM, Vikrant Singh <vikrant.subscribe@gmail.com>
wrote:

> Hello All,
> I need some guidance on understanding how to a fix done in latest release
> 3.0.0 . I am talking about following fix -
> https://issues.apache.org/jira/browse/CURATOR-247 .
>
> In my project we create some ephemeral nodes and monitor a cluster through
> a tree cache . Framework for treecache and ephemeral node is created
> using ExponentialBackoffRetry with retry interval of 1 sec and retry count
> of 29 (which is MAX_RETRIES_LIMIT ) .  We do kill the process moment  we
> get TreeCacheEvent.Type.CONNECTION_LOST event .
>
> As process restart is really expensive, I want to understand how I can
> leverage from this fix.
>
> Please help me in understanding what is the issue and how it may affect a
> setup like ours. We are still not on 3.0.0.
>
> Thanks,
> Vikrant
>
>
>

Mime
View raw message