[jira] [Commented] (SOLR-15286) A brand new replica in the legacy setup reports healthy before replicating index from its leader

["Pushkar Raste (Jira)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/SOLR-15286?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17308170#comment-17308170 ] 

Pushkar Raste commented on SOLR-15286:
--------------------------------------

Here is a solution I am thinking of.
 # On startup check if the node is follower.
 # If yes, check the index generation on the node and check the replicable index generation on the leader
 # Mark the node (follower) health only if its index generation is with a configurable threshold from the leader index generation.
 # Once the node has caught with the leader (within the configuration threshold) mark it an instance variable to indicate to indicate a initial sync with leader is done

We can have another option to always ensure that replica is within acceptable index generation threshold from its leader.

> A brand new replica in the legacy setup reports healthy before replicating index from its leader
> ------------------------------------------------------------------------------------------------
>
>                 Key: SOLR-15286
>                 URL: https://issues.apache.org/jira/browse/SOLR-15286
>             Project: Solr
>          Issue Type: Bug
>      Security Level: Public(Default Security Level. Issues are Public) 
>          Components: replication (java)
>    Affects Versions: 8.8.1
>            Reporter: Pushkar Raste
>            Priority: Major
>
> In the legacy mode when you add a brand new replica it immediately starts reporting healthy even if it hasn't fully replicated index from its leader. This issue is also exhibited when you shut down a replica and start it after a lot of data is indexed on the leader.
> If the replica reports healthy LB would continue to forward incoming requests to it and this would result in inconsistent data being retuned to the caller. 



--
This message was sent by Atlassian Jira
(v8.3.4#803005)