[CASSANDRA-15949] NPE thrown while updating speculative execution time if table is removed during task execution

• Type: Bug
• Status: Resolved
• Priority: Normal
• Resolution: Fixed
• Fix Version/s: 4.0-beta3, 4.0
• Component/s: Local/Other
• Bug Category: Degradation
• Severity: Normal
• Complexity: Normal
• Discovered By: User Report
• Platform: All
• Since Version: 4.0-alpha

Source Control Link

https://github.com/apache/cassandra/commit/ca027c3c2262f5a6789dbf41a5656a7bcf02a5f2

Test and Documentation Plan

• clean Circle run
• an additional test that provides guardrails around the Keyspace opening process (at least as it's used by the speculative retry threshold update task)

• Assignee: Caleb Rackliffe
• Reporter: Jon Meredith

Authors

Caleb Rackliffe

Reviewers

Aleksey Yeschenko, David Capwell

• Created: 15/Jul/20 20:06
• Updated: 16/Mar/22 14:14
• Resolved: 16/Sep/20 20:44

Description

CASSANDRA-14338 fixed the scheduling the speculation retry threshold calculation, but if the task happens to be scheduled while a table is being dropped, it triggers an NPE.

ERROR 2020-07-14T11:34:55,762 [OptionalTasks:1] org.apache.cassandra.service.CassandraDaemon:446 - Exception in thread Thread[OptionalTasks:1,5,main]
java.lang.NullPointerException: null
       at org.apache.cassandra.db.Keyspace.initCf(Keyspace.java:444) ~[cassandra-4.0.0.jar:4.0.0]
       at org.apache.cassandra.db.Keyspace.<init>(Keyspace.java:346) ~[cassandra-4.0.0.jar:4.0.0]
       at org.apache.cassandra.db.Keyspace.open(Keyspace.java:139) ~[cassandra-4.0.0.jar:4.0.0]
       at org.apache.cassandra.db.Keyspace.open(Keyspace.java:116) ~[cassandra-4.0.0.jar:4.0.0]
       at org.apache.cassandra.db.Keyspace$1.apply(Keyspace.java:102) ~[cassandra-4.0.0.jar:4.0.0]
       at org.apache.cassandra.db.Keyspace$1.apply(Keyspace.java:99) ~[cassandra-4.0.0.jar:4.0.0]
       at com.google.common.collect.Iterables$5.lambda$forEach$0(Iterables.java:704) ~[guava-27.0-jre.jar:?]
       at com.google.common.collect.IndexedImmutableSet.forEach(IndexedImmutableSet.java:45) ~[guava-27.0-jre.jar:?]
       at com.google.common.collect.Iterables$5.forEach(Iterables.java:704) ~[guava-27.0-jre.jar:?]
       at org.apache.cassandra.service.CassandraDaemon.lambda$setup$2(CassandraDaemon.java:412) ~[cassandra-4.0.0.jar:4.0.0]
       at org.apache.cassandra.concurrent.DebuggableScheduledThreadPoolExecutor$UncomplainingRunnable.run(DebuggableScheduledThreadPoolExecutor.java:118) [cassandra-4.0.0.jar:4.0.0]
       at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515) [?:?]
       at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:305) [?:?]
       at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:305) [?:?]
       at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) [?:?]
       at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) [?:?]
       at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30) [netty-all-4.1.37.Final.jar:4.1.37.Final]
       at java.lang.Thread.run(Thread.java:834) [?:?]