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From: Benjamin Reed <breed@apache.org>
Date: Wed, 2 Nov 2016 18:02:27 -0400
Message-ID: <CAKR25ETPvPUCP286km1tbFePzTjdLA20XhLwS3cgD2UADDU-Yw@mail.gmail.com>
Subject: Re: zookeeper client seems to timeout earlier than it should
To: "user@zookeeper.apache.org" <user@zookeeper.apache.org>
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archived-at: Wed, 02 Nov 2016 22:02:30 -0000

clients need to make sure they move off of a dead server on to a new
one to keep their connection alive, so generally if the client hasn't
heard from the server in 2/3 * sessionTimeout it will try to connect
to someone else. if it waited the whole 4 seconds, when connected to
an active server it would be pronounced dead on arrival.

ben

On Wed, Nov 2, 2016 at 5:11 PM, Whitney, Adam <Adam.Whitney@sony.com> wrote=
:
> (Sorry if this is a repost =E2=80=A6 I got a strange response to my origi=
nal email so I=E2=80=99m not sure if it went through or not)
>
> I have a zookeeper cluster with 3 nodes and tick time set to 2s
>
> When a client connects to the cluster I see a log entry like this:
>
> INFO  | Session establishment complete on server XXX, sessionid =3D XXX, =
negotiated timeout =3D 4000 | org.apache.zookeeper.ClientCnxn | main-SendTh=
read(XXX:2181)
>
> Notice the "negotiated timeout =3D 4000"
>
> But about once a day I see a log entry like this:
>
> INFO  | Client session timed out, have not heard from server in 2953ms fo=
r sessionid XXX, closing socket connection and attempting reconnect | org.a=
pache.zookeeper.ClientCnxn | main-SendThread(XXX:2181)
>
> Why would the client (apparently) timeout the session after only 2953ms i=
f the negotiated timeout was 4000ms?
>