Hi, I'm new to Solr and I'm tasked to upgrade our Solr 8.11.3 installation to Solr 9.6.1.
I'm running into some trouble with the create collection command when it's sent to a Solr 9.6.1 node with Solr 8.11.3 running as overseers. The command in Java is CollectionAdminRequest.createCollection(collectionName, configName, numShards, 0) .setAutoAddReplicas(false) .setRouterName("compositeId") .setCreateNodeSet("EMPTY") .setReplicationFactor(1); And the error that I see on the overseer can be either of the one below. I guess it depends on if the collection has been created (but deleted) before or not. If the collection has been created before but deleted. I'll see in the overseer (Solr 8) log 01:42:43.927 ERROR (OverseerThreadFactory-25-t...:8983_solr) [ ] o.a.s.c.a.c.OverseerCollectionMessageHandler Collection: test-collection_1.2 operation: create failed org.apache.solr.common.SolrException: Could not fully create collection: test-collection_1.2 at org.apache.solr.cloud.api.collections.CreateCollectionCmd.call(CreateCollectionCmd.java:218) ~[?:?] at org.apache.solr.cloud.api.collections.OverseerCollectionMessageHandler.processMessage(OverseerCollectionMessageHandler.java:271) ~[?:?] at org.apache.solr.cloud.OverseerTaskProcessor$Runner.run(OverseerTaskProcessor.java:524) ~[?:?] at org.apache.solr.common.util.ExecutorUtil$MDCAwareThreadPoolExecutor.lambda$execute$0(ExecutorUtil.java:218) ~[?:?] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) ~[?:?] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) ~[?:?] at java.lang.Thread.run(Thread.java:829) ~[?:?] But if the collection has never been created before, then I see in the overseer log 01:42:14.439 INFO (OverseerThreadFactory-25-thread-..._solr) [ ] o.a.s.c.a.c.CreateCollectionCmd Create collection test1-collection_1.2 01:42:14.442 INFO (OverseerCollectionConfigSetProcessor-...) [ ] o.a.s.c.OverseerTaskQueue Response ZK path: /overseer/collection-queue-work/qnr-0000707821 doesn't exist. Requestor may have disconnected from ZooKeeper 01:42:14.469 ERROR (OverseerStateUpdate-3026498...) [ ] o.a.s.c.Overseer Exception in Overseer main queue loop org.apache.zookeeper.KeeperException$NoNodeException: KeeperErrorCode = NoNode for /clusterstate.json at org.apache.zookeeper.KeeperException.create(KeeperException.java:118) ~[?:?] at org.apache.zookeeper.KeeperException.create(KeeperException.java:54) ~[?:?] at org.apache.zookeeper.ZooKeeper.setData(ZooKeeper.java:2561) ~[?:?] at org.apache.solr.common.cloud.SolrZkClient.lambda$setData$7(SolrZkClient.java:361) ~[?:?] at org.apache.solr.common.cloud.ZkCmdExecutor.retryOperation(ZkCmdExecutor.java:79) ~[?:?] at org.apache.solr.common.cloud.SolrZkClient.setData(SolrZkClient.java:361) ~[?:?] at org.apache.solr.cloud.overseer.ZkStateWriter.writePendingUpdates(ZkStateWriter.java:291) ~[?:?] at org.apache.solr.cloud.overseer.ZkStateWriter.writePendingUpdates(ZkStateWriter.java:217) ~[?:?] at org.apache.solr.cloud.overseer.ZkStateWriter.enqueueUpdate(ZkStateWriter.java:173) ~[?:?] at org.apache.solr.cloud.Overseer$ClusterStateUpdater.processQueueItem(Overseer.java:341) ~[?:?] at org.apache.solr.cloud.Overseer$ClusterStateUpdater.run(Overseer.java:271) ~[?:?] at java.lang.Thread.run(Thread.java:829) ~[?:?] 01:42:14.490 WARN (OverseerStateUpdate-3026498...) [ ] o.a.s.c.Overseer Exception when process message = { "replicationFactor":1, "fromApi":"true", "collection.configName":"test1-collection", "router.name":"compositeId", "createNodeSet":"EMPTY", "waitForFinalState":null, "pullReplicas":null, "async":"70e3b8e7-9ee1-468d-96f6-470900c4edbb", "router.field":null, "name":"test1-collection_1.2", "nrtReplicas":1, "numShards":2, "tlogReplicas":null, "alias":null, "operation":"create", "perReplicaState":null}, consider as bad message and poll out from the queue Is there a known incompatibility issue between Solr 9 (data node) and Solr 8 (overseer node) with CollectionAdminRequest.createCollection? This is what we have been doing for a long time and works with both data and overseer nodes are running Solr 8. Is there a way to get around this issue? Thanks, Patrick