Message Title

Since the beginning of the week (approximately) we're having transient failures in IndexingActionInterceptorTest. The logs contain the following error:
11:01:50,429 (main) DEBUG request:104 - ES client issued a ResponseException - not necessarily a problem
org.elasticsearch.client.ResponseException: POST http://localhost:9200/org.hibernate.search.test.interceptor.blog/org.hibernate.search.test.interceptor.Article,org.hibernate.search.test
.interceptor.TotalArticle/_delete_by_query/: HTTP/1.1 409 Conflict
{"took":3,"timed_out":false,"total":2,"deleted":1,"batches":1,"version_conflicts":1,"noops":0,"retries":{"bulk":0,"search":0},"throttled_millis":0,"requests_per_second":-1.0,"throttled_
until_millis":0,"failures":[{"index":"org.hibernate.search.test.interceptor.blog","type":"org.hibernate.search.test.interceptor.TotalArticle","id":"3","cause":{"type":"version_conflict_
engine_exception","reason":"[org.hibernate.search.test.interceptor.TotalArticle][3]: version conflict, current version [3] is different than the one provided [2]","index_uuid":"-oMMjrTs
RHOY64GKiID4Fg","shard":"0","index":"org.hibernate.search.test.interceptor.blog"},"status":409}]}
        at org.elasticsearch.client.RestClient$1.completed(RestClient.java:354)
        at org.elasticsearch.client.RestClient$1.completed(RestClient.java:343)
        at org.apache.http.concurrent.BasicFuture.completed(BasicFuture.java:119)
        at org.apache.http.impl.nio.client.DefaultClientExchangeHandlerImpl.responseCompleted(DefaultClientExchangeHandlerImpl.java:177)
        at org.apache.http.nio.protocol.HttpAsyncRequestExecutor.processResponse(HttpAsyncRequestExecutor.java:436)
        at org.apache.http.nio.protocol.HttpAsyncRequestExecutor.inputReady(HttpAsyncRequestExecutor.java:326)
        at org.apache.http.impl.nio.DefaultNHttpClientConnection.consumeInput(DefaultNHttpClientConnection.java:265)
        at org.apache.http.impl.nio.client.InternalIODispatch.onInputReady(InternalIODispatch.java:81)
        at org.apache.http.impl.nio.client.InternalIODispatch.onInputReady(InternalIODispatch.java:39)
        at org.apache.http.impl.nio.reactor.AbstractIODispatch.inputReady(AbstractIODispatch.java:114)
        at org.apache.http.impl.nio.reactor.BaseIOReactor.readable(BaseIOReactor.java:162)
        at org.apache.http.impl.nio.reactor.AbstractIOReactor.processEvent(AbstractIOReactor.java:337)
        at org.apache.http.impl.nio.reactor.AbstractIOReactor.processEvents(AbstractIOReactor.java:315)
        at org.apache.http.impl.nio.reactor.AbstractIOReactor.execute(AbstractIOReactor.java:276)
        at org.apache.http.impl.nio.reactor.BaseIOReactor.execute(BaseIOReactor.java:104)
        at org.apache.http.impl.nio.reactor.AbstractMultiworkerIOReactor$Worker.run(AbstractMultiworkerIOReactor.java:588)
        at java.lang.Thread.run(Thread.java:745)
11:01:50,430 (main) ERROR LogErrorHandler:69 - HSEARCH000058: Exception occurred org.hibernate.search.exception.SearchException: HSEARCH400007: Elasticsearch request failed.
 Request:
========
Method: POST
Path: /org.hibernate.search.test.interceptor.blog/org.hibernate.search.test.interceptor.Article,org.hibernate.search.test.interceptor.TotalArticle/_delete_by_query/
Data:
{
  "query": {
    "match_all": {}
  }
}

Response:
=========
Status: 409 Conflict
Error message: null
Cluster name: null
Cluster status: null


Primary Failure:
        Entity org.hibernate.search.test.interceptor.Article  Id null  Work Type  org.hibernate.search.backend.PurgeAllLuceneWork
Subsequent failures:
        Entity org.hibernate.search.test.interceptor.Article  Id null  Work Type  org.hibernate.search.backend.PurgeAllLuceneWork
        Entity org.hibernate.search.test.interceptor.Blog  Id null  Work Type  org.hibernate.search.backend.PurgeAllLuceneWork

org.hibernate.search.exception.SearchException: HSEARCH400007: Elasticsearch request failed.
 Request:
========
Method: POST
Path: /org.hibernate.search.test.interceptor.blog/org.hibernate.search.test.interceptor.Article,org.hibernate.search.test.interceptor.TotalArticle/_delete_by_query/
Data:
{
  "query": {
    "match_all": {}
  }
}
Response:
=========
Status: 409 Conflict
Error message: null
Cluster name: null
Cluster status: null


        at org.hibernate.search.elasticsearch.work.impl.DefaultElasticsearchRequestSuccessAssessor.checkSuccess(DefaultElasticsearchRequestSuccessAssessor.java:98)
        at org.hibernate.search.elasticsearch.work.impl.SimpleElasticsearchWork.execute(SimpleElasticsearchWork.java:64)
        at org.hibernate.search.elasticsearch.processor.impl.ElasticsearchWorkProcessor.executeUnsafe(ElasticsearchWorkProcessor.java:195)
        at org.hibernate.search.elasticsearch.processor.impl.ElasticsearchWorkProcessor.executeSafe(ElasticsearchWorkProcessor.java:159)
        at org.hibernate.search.elasticsearch.processor.impl.ElasticsearchWorkProcessor.executeSyncSafe(ElasticsearchWorkProcessor.java:105)
        at org.hibernate.search.elasticsearch.impl.ElasticsearchIndexManager.performOperations(ElasticsearchIndexManager.java:442)
        at org.hibernate.search.backend.impl.LocalBackendQueueProcessor.applyWork(LocalBackendQueueProcessor.java:58)
        at org.hibernate.search.backend.impl.WorkQueuePerIndexSplitter.commitOperations(WorkQueuePerIndexSplitter.java:66)
        at org.hibernate.search.backend.impl.TransactionalOperationDispatcher.dispatch(TransactionalOperationDispatcher.java:71)
        at org.hibernate.search.backend.impl.BatchedQueueingProcessor.performWorks(BatchedQueueingProcessor.java:72)
        at org.hibernate.search.backend.impl.PostTransactionWorkQueueSynchronization.afterCompletion(PostTransactionWorkQueueSynchronization.java:76)
        at org.hibernate.search.backend.impl.EventSourceTransactionContext$DelegateToSynchronizationOnAfterTx.doAfterTransactionCompletion(EventSourceTransactionContext.java:188)
        at org.hibernate.engine.spi.ActionQueue$AfterTransactionCompletionProcessQueue.afterTransactionCompletion(ActionQueue.java:964)
        at org.hibernate.engine.spi.ActionQueue.afterTransactionCompletion(ActionQueue.java:498)
        at org.hibernate.internal.SessionImpl.afterTransactionCompletion(SessionImpl.java:2432)
        at org.hibernate.engine.jdbc.internal.JdbcCoordinatorImpl.afterTransactionCompletion(JdbcCoordinatorImpl.java:473)
        at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl.afterCompletionCallback(JdbcResourceLocalTransactionCoordinatorImpl.java:166)
        at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl.access$200(JdbcResourceLocalTransactionCoordinatorImpl.java:38)
        at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl$TransactionDriverControlImpl.commit(JdbcResourceLocalTransactionCoordinatorImpl.java:222)
        at org.hibernate.engine.transaction.internal.TransactionImpl.commit(TransactionImpl.java:68)
        at org.hibernate.search.test.interceptor.IndexingActionInterceptorTest.testInterceptorWithMassIndexer(IndexingActionInterceptorTest.java:141)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
        at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
        at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
        at org.hibernate.testing.junit4.ExtendedFrameworkMethod.invokeExplosively(ExtendedFrameworkMethod.java:45)
        at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
        at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
        at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
        at org.hibernate.testing.junit4.FailureExpectedHandler.evaluate(FailureExpectedHandler.java:41)
        at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
        at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
        at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
        at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
        at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
        at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
        at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
        at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
        at org.hibernate.testing.junit4.BeforeClassCallbackHandler.evaluate(BeforeClassCallbackHandler.java:26)
        at org.hibernate.testing.junit4.AfterClassCallbackHandler.evaluate(AfterClassCallbackHandler.java:25)
        at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
        at org.junit.runners.Suite.runChild(Suite.java:128)
        at org.junit.runners.Suite.runChild(Suite.java:27)
        at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
        at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
        at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
        at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
        at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
        at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
        at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
        at org.junit.runner.JUnitCore.run(JUnitCore.java:115)
        at org.apache.maven.surefire.junitcore.JUnitCoreWrapper.createRequestAndRun(JUnitCoreWrapper.java:108)
        at org.apache.maven.surefire.junitcore.JUnitCoreWrapper.executeEager(JUnitCoreWrapper.java:78)
        at org.apache.maven.surefire.junitcore.JUnitCoreWrapper.execute(JUnitCoreWrapper.java:54)
        at org.apache.maven.surefire.junitcore.JUnitCoreProvider.invoke(JUnitCoreProvider.java:144)
        at org.apache.maven.surefire.booter.ForkedBooter.invokeProviderInSameClassLoader(ForkedBooter.java:203)
        at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:155)
        at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:103)
I suspect it's a pre-existing bug, but we only see it now because of https://github.com/hibernate/hibernate-search/pull/1432, which had the effect of not executing subsequent works in a changeset when one work fails (while previously we considered each work independent from the others). (Note that this was still the right choice, since it aligned the behavior on embedded Lucene).