com.google.gerrit.server.index.change.ReindexAfterRefUpdate : Failed to reindex changes after Event[xxx,refs/heads/m/xxx ....

[Makson Lee]

i got the following error in log file, my gerrit version is 2.15-rc2, and i have manifest-subscription plugin [1] installed, it will create some refs/heads/m/xxx references in specific repositories, what i don't understand is, why gerrit try to reindex them?

[1] https://gerrit.googlesource.com/plugins/manifest-subscription/

[2017-11-09 09:51:41,086] [Index-Batch-1] ERROR com.google.gerrit.server.index.change.ReindexAfterRefUpdate : Failed to reindex changes after Event[xxx,refs/heads/m/xxx: 0000000000000000000000000000000000000000 -> 6535ae6cccd4dc23a0ce5feac3a7fae30055c38d]

java.lang.NullPointerException

        at com.google.gerrit.server.index.change.ChangeIndexRewriter.isIndexPredicate(ChangeIndexRewriter.java:245)

        at com.google.gerrit.server.index.change.ChangeIndexRewriter.rewriteImpl(ChangeIndexRewriter.java:183)

        at com.google.gerrit.server.index.change.ChangeIndexRewriter.rewriteImpl(ChangeIndexRewriter.java:208)

        at com.google.gerrit.server.index.change.ChangeIndexRewriter.rewriteImpl(ChangeIndexRewriter.java:156)

        at com.google.gerrit.server.index.change.ChangeIndexRewriter.rewrite(ChangeIndexRewriter.java:140)

        at com.google.gerrit.index.query.QueryProcessor.query(QueryProcessor.java:224)

        at com.google.gerrit.index.query.QueryProcessor.query(QueryProcessor.java:174)

        at com.google.gerrit.index.query.QueryProcessor.query(QueryProcessor.java:157)

        at com.google.gerrit.index.query.InternalQuery.query(InternalQuery.java:74)

        at com.google.gerrit.server.query.change.InternalChangeQuery.byBranchNew(InternalChangeQuery.java:148)

        at com.google.gerrit.server.index.change.ReindexAfterRefUpdate$GetChanges.impl(ReindexAfterRefUpdate.java:158)

        at com.google.gerrit.server.index.change.ReindexAfterRefUpdate$GetChanges.impl(ReindexAfterRefUpdate.java:146)

        at com.google.gerrit.server.index.change.ReindexAfterRefUpdate$Task.call(ReindexAfterRefUpdate.java:136)

        at com.google.common.util.concurrent.TrustedListenableFutureTask$TrustedFutureInterruptibleTask.runInterruptibly(TrustedListenableFutureTask.java:111)

        at com.google.common.util.concurrent.InterruptibleTask.run(InterruptibleTask.java:58)

        at com.google.common.util.concurrent.TrustedListenableFutureTask.run(TrustedListenableFutureTask.java:75)

        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)

        at java.util.concurrent.FutureTask.run(FutureTask.java:266)

        at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180)

        at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)

        at com.google.gerrit.server.git.WorkQueue$Task.run(WorkQueue.java:435)

        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)

        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)

        at java.lang.Thread.run(Thread.java:748)

[Makson Lee]

the plugin tries to create references when loading, and the index [1] is not ready yet, so how can we wait for index to be ready in a plugin?

[1] https://gerrit.googlesource.com/gerrit/+/stable-2.15/gerrit-server/src/main/java/com/google/gerrit/server/index/change/ChangeIndexRewriter.java#153