zookeeper-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Michael Han (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (ZOOKEEPER-2819) Changing membership configuration via rolling restart does not work on 3.5.x.
Date Mon, 26 Jun 2017 23:28:00 GMT

    [ https://issues.apache.org/jira/browse/ZOOKEEPER-2819?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16063970#comment-16063970
] 

Michael Han commented on ZOOKEEPER-2819:
----------------------------------------

bq. the cluster is partitioned and an admin may want to force a minority of servers to form
a cluster

Yeah, I think being able to deal with the partitioned / none quorum forming case is important
from an operational point of view. Actually I think this is the main reason we should continue
supporting rolling restart while advocating dynamic reconfig as the main approach to do reconfig.

bq. One idea of how this can be achieved is by setting reconfigEnable parameter to false

Created ZOOKEEPER-2820 to document this. 



> Changing membership configuration via rolling restart does not work on 3.5.x.
> -----------------------------------------------------------------------------
>
>                 Key: ZOOKEEPER-2819
>                 URL: https://issues.apache.org/jira/browse/ZOOKEEPER-2819
>             Project: ZooKeeper
>          Issue Type: Bug
>          Components: quorum, server
>    Affects Versions: 3.5.0, 3.5.1, 3.5.2, 3.5.3
>            Reporter: Michael Han
>            Assignee: Michael Han
>            Priority: Critical
>
> In 3.5.x there is no easy way of changing the membership config using rolling restarts
because of the introduction of dynamic reconfig feature in ZOOKEEPER-107, which automatically
manages membership configuration parameters.
> ZOOKEEPER-2014 introduced a reconfigEnabled flag to turn on / off the reconfig feature.
We can use same flag and when it sets to false, it should disable both in memory and on disk
updates of membership configuration information, besides disabling the reconfig commands on
CLI which ZOOKEEPER-2014 already did, so users can continue using rolling restarts if needed.

> We should also document explicitly the support of membership changes via rolling restarts
will be deprecated at what release time frame and promote reconfig as the replacement.
> The problem was raised at user mailing list by Guillermo Vega-Toro, reference thread:
> http://zookeeper-user.578899.n2.nabble.com/How-to-add-nodes-to-a-Zookeeper-3-5-3-beta-ensemble-with-reconfigEnabled-false-td7583138.html



--
This message was sent by Atlassian JIRA
(v6.4.14#64029)

Mime
View raw message