[CASSANDRA-4095] Internal error processing get_slice (NullPointerException)

• Type: Bug
• Status: Resolved
• Priority: Low
• Resolution: Fixed
• Fix Version/s: 1.0.9, 1.1.0

Environment

Java(TM) SE Runtime Environment (build 1.6.0_30-b12)

• Severity: Low
• Assignee: Jonathan Ellis
• Reporter: John Laban

Authors

Jonathan Ellis

Reviewers

Vijay

• Created: 28/Mar/12 03:09
• Updated: 16/Apr/19 09:32
• Resolved: 30/Mar/12 15:24

Description

I get this pretty regularly. It seems to happen transiently on multiple nodes in my cluster, every so often, and goes away.

ERROR [Thrift:45] 2012-03-26 19:59:12,024 Cassandra.java (line 3041) Internal error processing get_slice
java.lang.NullPointerException
at org.apache.cassandra.db.SliceFromReadCommand.maybeGenerateRetryCommand(SliceFromReadCommand.java:76)
at org.apache.cassandra.service.StorageProxy.fetchRows(StorageProxy.java:724)
at org.apache.cassandra.service.StorageProxy.read(StorageProxy.java:564)
at org.apache.cassandra.thrift.CassandraServer.readColumnFamily(CassandraServer.java:128)
at org.apache.cassandra.thrift.CassandraServer.getSlice(CassandraServer.java:283)
at org.apache.cassandra.thrift.CassandraServer.multigetSliceInternal(CassandraServer.java:365)
at org.apache.cassandra.thrift.CassandraServer.get_slice(CassandraServer.java:326)
at org.apache.cassandra.thrift.Cassandra$Processor$get_slice.process(Cassandra.java:3033)
at org.apache.cassandra.thrift.Cassandra$Processor.process(Cassandra.java:2889)
at org.apache.cassandra.thrift.CustomTThreadPoolServer$WorkerProcess.run(CustomTThreadPoolServer.java:187)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:662)

The line in question is (I think) the one below, so it looks like the column family reference for a row can sometimes be null?

int liveColumnsInRow = row != null ? row.cf.getLiveColumnCount() : 0;

Here is my column family (on 1.0.8):

ColumnFamily: WorkQueue (Super)
Key Validation Class: org.apache.cassandra.db.marshal.UTF8Type
Default column value validator: org.apache.cassandra.db.marshal.UTF8Type
Columns sorted by: org.apache.cassandra.db.marshal.UTF8Type/org.apache.cassandra.db.marshal.UTF8Type
Row cache size / save period in seconds / keys to save : 0.0/0/all
Row Cache Provider: org.apache.cassandra.cache.ConcurrentLinkedHashCacheProvider
Key cache size / save period in seconds: 0.0/0
GC grace seconds: 0
Compaction min/max thresholds: 4/32
Read repair chance: 0.0
Replicate on write: false
Bloom Filter FP chance: default
Built indexes: []
Compaction Strategy: org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy