In simple words, if Lucene indexes were created by a new version (7.1.0), then replicated to others that are still in the older version, they won't understand the index, and the event processors start throwing exceptions.
This can be simply seen by just re-enabling the query execution in the DUnit tests and commenting out the check blocks: [develop SHA: 68629356f561a932f5dfbace70b01d9971a42473] In LuceneEventListener if (cache.hasMemberOlderThan(KnownVersion.GEODE_1_15_0)) { logger.info("Some members are older than " + KnownVersion.GEODE_1_15_0.getName()); return false; } In IndexRepositoryFactory: if (userRegion.getCache() != null && userRegion.getCache().hasMemberOlderThan(KnownVersion.GEODE_1_15_0)) { logger.info("Some members are older than " + KnownVersion.GEODE_1_15_0.getName()); return null; } This is the exception that will be encountered: [Exception] [vm2_v1.2.0] [warn 2021/09/27 14:24:42.251 PDT <Event Processor for GatewaySender_AsyncEventQueue_index#_aRegion_5> tid=102] An Exception occurred. The dispatcher will continue. [vm2_v1.2.0] org.apache.geode.InternalGemFireError: Unable to create index repository [vm2_v1.2.0] at org.apache.geode.cache.lucene.internal.AbstractPartitionedRepositoryManager.lambda$computeRepository$0(AbstractPartitionedRepositoryManager.java:118) [vm2_v1.2.0] at java.util.concurrent.ConcurrentHashMap.compute(ConcurrentHashMap.java:1853) [vm2_v1.2.0] at org.apache.geode.cache.lucene.internal.AbstractPartitionedRepositoryManager.computeRepository(AbstractPartitionedRepositoryManager.java:108) [vm2_v1.2.0] at org.apache.geode.cache.lucene.internal.AbstractPartitionedRepositoryManager.getRepository(AbstractPartitionedRepositoryManager.java:137) [vm2_v1.2.0] at org.apache.geode.cache.lucene.internal.AbstractPartitionedRepositoryManager.getRepository(AbstractPartitionedRepositoryManager.java:76) [vm2_v1.2.0] at org.apache.geode.cache.lucene.internal.LuceneEventListener.process(LuceneEventListener.java:87) [vm2_v1.2.0] at org.apache.geode.cache.lucene.internal.LuceneEventListener.processEvents(LuceneEventListener.java:64) [vm2_v1.2.0] at org.apache.geode.internal.cache.wan.GatewaySenderEventCallbackDispatcher.dispatchBatch(GatewaySenderEventCallbackDispatcher.java:154) [vm2_v1.2.0] at org.apache.geode.internal.cache.wan.GatewaySenderEventCallbackDispatcher.dispatchBatch(GatewaySenderEventCallbackDispatcher.java:80) [vm2_v1.2.0] at org.apache.geode.internal.cache.wan.AbstractGatewaySenderEventProcessor.processQueue(AbstractGatewaySenderEventProcessor.java:609) [vm2_v1.2.0] at org.apache.geode.internal.cache.wan.AbstractGatewaySenderEventProcessor.run(AbstractGatewaySenderEventProcessor.java:1051) [vm2_v1.2.0] Caused by: org.apache.lucene.index.IndexFormatTooNewException: Format version is not supported (resource BufferedChecksumIndexInput(segments_2)): 7 (needs to be between 4 and 6) [vm2_v1.2.0] at org.apache.lucene.codecs.CodecUtil.checkHeaderNoMagic(CodecUtil.java:216) [vm2_v1.2.0] at org.apache.lucene.index.SegmentInfos.readCommit(SegmentInfos.java:302) [vm2_v1.2.0] at org.apache.lucene.index.SegmentInfos.readCommit(SegmentInfos.java:286) [vm2_v1.2.0] at org.apache.lucene.index.IndexWriter.<init>(IndexWriter.java:938) [vm2_v1.2.0] at org.apache.geode.cache.lucene.internal.IndexRepositoryFactory.computeIndexRepository(IndexRepositoryFactory.java:84) [vm2_v1.2.0] at org.apache.geode.cache.lucene.internal.PartitionedRepositoryManager.computeRepository(PartitionedRepositoryManager.java:42) [vm2_v1.2.0] at org.apache.geode.cache.lucene.internal.AbstractPartitionedRepositoryManager.lambda$computeRepository$0(AbstractPartitionedRepositoryManager.java:116) [vm2_v1.2.0] ... 10 more Also: [vm2_v1.2.0] [warn 2021/09/27 14:24:42.134 PDT <Event Processor for GatewaySender_AsyncEventQueue_index#_aRegion_7> tid=106] An Exception occurred. The dispatcher will continue. [vm2_v1.2.0] org.apache.geode.InternalGemFireError: Unable to create index repository [vm2_v1.2.0] at org.apache.geode.cache.lucene.internal.AbstractPartitionedRepositoryManager.lambda$computeRepository$0(AbstractPartitionedRepositoryManager.java:118) [vm2_v1.2.0] at java.util.concurrent.ConcurrentHashMap.compute(ConcurrentHashMap.java:1853) [vm2_v1.2.0] at org.apache.geode.cache.lucene.internal.AbstractPartitionedRepositoryManager.computeRepository(AbstractPartitionedRepositoryManager.java:108) [vm2_v1.2.0] at org.apache.geode.cache.lucene.internal.AbstractPartitionedRepositoryManager.getRepository(AbstractPartitionedRepositoryManager.java:137) [vm2_v1.2.0] at org.apache.geode.cache.lucene.internal.AbstractPartitionedRepositoryManager.getRepository(AbstractPartitionedRepositoryManager.java:76) [vm2_v1.2.0] at org.apache.geode.cache.lucene.internal.LuceneEventListener.process(LuceneEventListener.java:87) [vm2_v1.2.0] at org.apache.geode.cache.lucene.internal.LuceneEventListener.processEvents(LuceneEventListener.java:64) [vm2_v1.2.0] at org.apache.geode.internal.cache.wan.GatewaySenderEventCallbackDispatcher.dispatchBatch(GatewaySenderEventCallbackDispatcher.java:154) [vm2_v1.2.0] at org.apache.geode.internal.cache.wan.GatewaySenderEventCallbackDispatcher.dispatchBatch(GatewaySenderEventCallbackDispatcher.java:80) [vm2_v1.2.0] at org.apache.geode.internal.cache.wan.AbstractGatewaySenderEventProcessor.processQueue(AbstractGatewaySenderEventProcessor.java:609) [vm2_v1.2.0] at org.apache.geode.internal.cache.wan.AbstractGatewaySenderEventProcessor.run(AbstractGatewaySenderEventProcessor.java:1051) [vm2_v1.2.0] Caused by: org.apache.lucene.index.IndexFormatTooNewException: Format version is not supported (resource BufferedChecksumIndexInput(segments_2)): 7 (needs to be between 4 and 6) [vm2_v1.2.0] at org.apache.lucene.codecs.CodecUtil.checkHeaderNoMagic(CodecUtil.java:216) [vm2_v1.2.0] at org.apache.lucene.index.SegmentInfos.readCommit(SegmentInfos.java:302) [vm2_v1.2.0] at org.apache.lucene.index.SegmentInfos.readCommit(SegmentInfos.java:286) [vm2_v1.2.0] at org.apache.lucene.index.IndexWriter.<init>(IndexWriter.java:938) [vm2_v1.2.0] at org.apache.geode.cache.lucene.internal.IndexRepositoryFactory.computeIndexRepository(IndexRepositoryFactory.java:84) [vm2_v1.2.0] at org.apache.geode.cache.lucene.internal.PartitionedRepositoryManager.computeRepository(PartitionedRepositoryManager.java:42) [vm2_v1.2.0] at org.apache.geode.cache.lucene.internal.AbstractPartitionedRepositoryManager.lambda$computeRepository$0(AbstractPartitionedRepositoryManager.java:116) [vm2_v1.2.0] ... 10 more ________________________________ From: Jacob Barrett <jabarr...@vmware.com> Sent: Monday, September 27, 2021 2:08 PM To: dev@geode.apache.org <dev@geode.apache.org> Subject: Re: [DISCUSS] Upgrading to Lucene 7.1.0 > On Sep 27, 2021, at 11:48 AM, nabarun nag <n...@apache.org> wrote: > > Recently, a commit was pushed to develop which upgraded the Lucene > version used in Apache Geode to 7.1.0. These new Lucene indexes are > not compatible with the previous versions hence it breaks the rolling > upgrade contract. We are no longer able to execute Lucene queries when > there are severs of mixed versions in the cluster. Can you describe the problem with a little more detail? Does this mean that while there is a mix the execution throws an exception on all servers or is there a subset for which it works? If there is a subset for which it works, are those instances sufficient to provide accurate results if the instances that fail are ignored? -Jake