[
https://issues.apache.org/jira/browse/ZOOKEEPER-3056?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16509199#comment-16509199
]
Michael Han commented on ZOOKEEPER-3056:
----------------------------------------
{quote}It's a trade-off between admin time and server side code complexity for
sure.
{quote}
I agree. If a snapshot-less use case is rare, it's better to provide an admin
ool to force generate a snapshot before upgrade (or migrate data), to keep a
simple server side code.
{quote}I do believe ZOOKEEPER-2325is a good feature and it would be a shame to
set it off by default.
{quote}
I agree, data consistency is important and even if we decide to provide such a
flag, the check should be enabled by default.
> Fails to load database with missing snapshot file but valid transaction log
> file
> --------------------------------------------------------------------------------
>
> Key: ZOOKEEPER-3056
> URL: https://issues.apache.org/jira/browse/ZOOKEEPER-3056
> Project: ZooKeeper
> Issue Type: Bug
> Components: server
> Affects Versions: 3.5.3, 3.5.4
> Reporter: Michael Han
> Priority: Critical
>
> [An
> issue|https://lists.apache.org/thread.html/cc17af6ef05d42318f74148f1a704f16934d1253f1472cccc1a93b4b@%3Cdev.zookeeper.apache.org%3E]
> was reported when a user failed to upgrade from 3.4.10 to 3.5.4 with missing
> snapshot file.
> The code complains about missing snapshot file is
> [here|https://github.com/apache/zookeeper/blob/release-3.5.4/src/java/main/org/apache/zookeeper/server/persistence/FileTxnSnapLog.java#L206]
> which is introduced as part of ZOOKEEPER-2325.
> With this check, ZK will not load the db without a snapshot file, even the
> transaction log files are present and valid. This could be a problem for
> restoring a ZK instance which does not have a snapshot file but have a sound
> state (e.g. it crashes before being able to take the first snap shot with a
> large snapCount parameter configured).
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
