[ 
https://issues.apache.org/jira/browse/SOLR-9092?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15419305#comment-15419305
 ] 

Shalin Shekhar Mangar commented on SOLR-9092:
---------------------------------------------

+1 to the patch. To summarise, we always delete the replica from the cluster 
state. But we attempt to send the core admin delete request only if that node 
is actually up. No new parameters are introduced.

> Add safety checks to delete replica/shard/collection commands
> -------------------------------------------------------------
>
>                 Key: SOLR-9092
>                 URL: https://issues.apache.org/jira/browse/SOLR-9092
>             Project: Solr
>          Issue Type: Improvement
>            Reporter: Varun Thacker
>            Assignee: Varun Thacker
>            Priority: Minor
>         Attachments: SOLR-9092.patch
>
>
> We should verify the delete commands against live_nodes to make sure the API 
> can atleast be executed correctly
> If we have a two node cluster, a collection with 1 shard 2 replica. Call the 
> delete replica command against for the replica whose node is currently down.
> You get an exception:
> {code}
> <response>
>    <lst name="responseHeader">
>       <int name="status">0</int>
>       <int name="QTime">5173</int>
>    </lst>
>    <lst name="failure">
>       <str 
> name="192.168.1.101:7574_solr">org.apache.solr.client.solrj.SolrServerException:Server
>  refused connection at: http://192.168.1.101:7574/solr</str>
>    </lst>
> </response>
> {code}
> At this point the entry for the replica is gone from state.json . The client 
> application retries since an error was thrown but the delete command will 
> never succeed now and an error like this will be seen-
> {code}
> <response>
>    <lst name="responseHeader">
>       <int name="status">400</int>
>       <int name="QTime">137</int>
>    </lst>
>    <str name="Operation deletereplica caused 
> exception:">org.apache.solr.common.SolrException:org.apache.solr.common.SolrException:
>  Invalid replica : core_node3 in shard/collection : shard1/gettingstarted 
> available replicas are core_node1</str>
>    <lst name="exception">
>       <str name="msg">Invalid replica : core_node3 in shard/collection : 
> shard1/gettingstarted available replicas are core_node1</str>
>       <int name="rspCode">400</int>
>    </lst>
>    <lst name="error">
>       <lst name="metadata">
>          <str name="error-class">org.apache.solr.common.SolrException</str>
>          <str 
> name="root-error-class">org.apache.solr.common.SolrException</str>
>       </lst>
>       <str name="msg">Invalid replica : core_node3 in shard/collection : 
> shard1/gettingstarted available replicas are core_node1</str>
>       <int name="code">400</int>
>    </lst>
> </response>
> {code}
> For create collection/add-replica we check the "createNodeSet" and "node" 
> params respectively against live_nodes to make sure it has a chance of 
> succeeding.
> We should add a check against live_nodes for the delete commands as well.
> Another situation where I saw this can be a problem - A second solr cluster 
> cloned from the first but the script didn't correctly change the hostnames in 
> the state.json file. When a delete command was issued against the second 
> cluster Solr deleted the replica from the first cluster.
> In the above case the script was buggy obviously but if we verify against 
> live_nodes then Solr wouldn't have gone ahead and deleted replicas not 
> belonging to its cluster.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]

Reply via email to