In Solr 8.4, a new timeout setting was applied to inter-node replication. Replica updates can time out after only 20 seconds, leaving solr.log messages saying that task or request processing has “stalled,” like these:
1 2 3 | 2021-12-13 19:13:32.265 WARN (qtp496729294-22) [c:sitecore_master_index s:shard1 r:core_node4 x:sitecore_master_index_shard1_replica_n3] o.a.s.u.SolrCmdDistributor Unable to finish sending updates => java.io.IOException: Task queue processing has stalled for 20194 ms with 0 remaining elements to process. solr.log:49852:2022-02-15 18:58:41.805 ERROR (qtp496729294-190188) [c:sitecore_master_index s:shard1 r:core_node4 x:sitecore_master_index_shard1_replica_n3] o.a.s.u.p.DistributedZkUpdateProcessor Setting up to try to start recovery on replica core_node2 with url http://10.22.9.165:8983/solr/sitecore_master_index_shard1_replica_n1/ by increasing leader term => java.io.IOException: Request processing has stalled for 20100ms with 100 remaining elements in the queue. |
Note the timeout values just above 20000ms. If you are using Solr 8.4 or later and experience these timeout messages, contact SearchStax Support. We can reset the timing window to a larger value for you.
Questions?
Do not hesitate to contact the SearchStax Support Desk.