[
https://issues.apache.org/jira/browse/SOLR-18298?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Jerry updated SOLR-18298:
-------------------------
Description:
Curator's RECONNECTED event is different from the previous RECONNECTED event.
Before Solr10, the OnReconnect is only triggered after a session expiration and
reconnection.
Check the following
[https://github.com/apache/solr/blob/fdb5314279657f7895a90123436d834e81ea3157/solr/solrj-zookeeper/src/java/org/apache/solr/common/cloud/ConnectionManager.java#L165]
[https://github.com/apache/solr/blob/fdb5314279657f7895a90123436d834e81ea3157/solr/solrj-zookeeper/src/java/org/apache/solr/common/cloud/ConnectionManager.java#L199]
But Curator's RECONNECTED event is triggered every time a Solr node is
disconnected from a ZooKeeper instance and reconnected to another
ZooKeeper instance
Therefore, currently ZkController.onReconnect is invoked every time a Solr
node is disconnected from a ZooKeeper instance and reconnected, which is a huge
overhead, especially when we need to rolling restart a ZooKeeper Cluster. It
can take more than 10 minutes for a small Solr cluster to level out.
Similiarly, now ZkController.onDisconnect is triggered just after a
disconnection from a Zookeeper instance. It should only be triggered after a
session expiration.
The PR restores the Solr 9 behavior, triggering re-election and other
initialization staff only when the session actually expires, which
significantly reduces performance overhead during network hiccups.
was:
Curator's RECONNECTED event is different from the previous RECONNECTED event.
Before Solr10, the OnReconnect is only triggered after a session expiration and
reconnection.
Check the following
https://github.com/apache/solr/blob/fdb5314279657f7895a90123436d834e81ea3157/solr/solrj-zookeeper/src/java/org/apache/solr/common/cloud/ConnectionManager.java#L165
https://github.com/apache/solr/blob/fdb5314279657f7895a90123436d834e81ea3157/solr/solrj-zookeeper/src/java/org/apache/solr/common/cloud/ConnectionManager.java#L199
But Curator's RECONNECTED event is triggered every time a Solr node is
disconnected from a ZooKeeper instance and reconnected to another
ZooKeeper instance
Therefore, currently ZkController.onReconnect is invoked every time a Solr
node is disconnected from a ZooKeeper instance and reconnected, which is a huge
overhead, especially when we need to rolling restart a ZooKeeper Cluster. It
can take more than 10 minutes for a small Solr cluster to level out.
Similiarly, now ZkController.onDisconnect is triggered just after a
disconnection from a Zookeeper instance. It should only be triggered after a
session expiration.
> ZkController.onReconnect Is Triggered Unnecessarily
> ---------------------------------------------------
>
> Key: SOLR-18298
> URL: https://issues.apache.org/jira/browse/SOLR-18298
> Project: Solr
> Issue Type: Bug
> Components: SolrCloud
> Affects Versions: 10.0
> Reporter: Jerry
> Priority: Major
> Labels: patch, pull-request-available, zookeeper
> Time Spent: 20m
> Remaining Estimate: 0h
>
> Curator's RECONNECTED event is different from the previous RECONNECTED event.
> Before Solr10, the OnReconnect is only triggered after a session expiration
> and reconnection.
> Check the following
> [https://github.com/apache/solr/blob/fdb5314279657f7895a90123436d834e81ea3157/solr/solrj-zookeeper/src/java/org/apache/solr/common/cloud/ConnectionManager.java#L165]
>
> [https://github.com/apache/solr/blob/fdb5314279657f7895a90123436d834e81ea3157/solr/solrj-zookeeper/src/java/org/apache/solr/common/cloud/ConnectionManager.java#L199]
> But Curator's RECONNECTED event is triggered every time a Solr node is
> disconnected from a ZooKeeper instance and reconnected to another
> ZooKeeper instance
> Therefore, currently ZkController.onReconnect is invoked every time a Solr
> node is disconnected from a ZooKeeper instance and reconnected, which is a
> huge overhead, especially when we need to rolling restart a ZooKeeper
> Cluster. It can take more than 10 minutes for a small Solr cluster to level
> out.
> Similiarly, now ZkController.onDisconnect is triggered just after a
> disconnection from a Zookeeper instance. It should only be triggered after a
> session expiration.
> The PR restores the Solr 9 behavior, triggering re-election and other
> initialization staff only when the session actually expires, which
> significantly reduces performance overhead during network hiccups.
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
