[CASSANDRA-5529] thrift_max_message_length_in_mb makes long-lived connections error out

• Type: Bug
• Status: Resolved
• Priority: Normal
• Resolution: Fixed
• Fix Version/s: 1.1.12, 1.2.6
• Component/s: Legacy/CQL
• Severity: Normal
• Assignee: Jonathan Ellis
• Reporter: Rob Timpe

Authors

Jonathan Ellis

Reviewers

T Jake Luciani

• Created: 01/May/13 00:54
• Updated: 16/Apr/19 09:32
• Resolved: 21/May/13 18:55

Description

When running mapreduce jobs that read directly from cassandra, the job will sometimes fail with an exception like this:

java.lang.RuntimeException: com.rockmelt.org.apache.thrift.TException: Message length exceeded: 40
at org.apache.cassandra.hadoop.ColumnFamilyRecordReader$StaticRowIterator.maybeInit(ColumnFamilyRecordReader.java:400)
at org.apache.cassandra.hadoop.ColumnFamilyRecordReader$StaticRowIterator.computeNext(ColumnFamilyRecordReader.java:406)
at org.apache.cassandra.hadoop.ColumnFamilyRecordReader$StaticRowIterator.computeNext(ColumnFamilyRecordReader.java:329)
at com.google.common.collect.AbstractIterator.tryToComputeNext(AbstractIterator.java:143)
at com.google.common.collect.AbstractIterator.hasNext(AbstractIterator.java:138)
at org.apache.cassandra.hadoop.ColumnFamilyRecordReader.getProgress(ColumnFamilyRecordReader.java:109)
at org.apache.hadoop.mapred.MapTask$NewTrackingRecordReader.getProgress(MapTask.java:522)
at org.apache.hadoop.mapred.MapTask$NewTrackingRecordReader.nextKeyValue(MapTask.java:547)
at org.apache.hadoop.mapreduce.MapContext.nextKeyValue(MapContext.java:67)
at org.apache.hadoop.mapreduce.Mapper.run(Mapper.java:143)
at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:771)
at org.apache.hadoop.mapred.MapTask.run(MapTask.java:375)
at org.apache.hadoop.mapred.Child$4.run(Child.java:255)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:396)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1132)
at org.apache.hadoop.mapred.Child.main(Child.java:249)
Caused by: com.rockmelt.org.apache.thrift.TException: Message length exceeded: 40
at com.rockmelt.org.apache.thrift.protocol.TBinaryProtocol.checkReadLength(TBinaryProtocol.java:393)
at com.rockmelt.org.apache.thrift.protocol.TBinaryProtocol.readBinary(TBinaryProtocol.java:363)
at org.apache.cassandra.thrift.Column.read(Column.java:528)
at org.apache.cassandra.thrift.ColumnOrSuperColumn.read(ColumnOrSuperColumn.java:507)
at org.apache.cassandra.thrift.KeySlice.read(KeySlice.java:408)
at org.apache.cassandra.thrift.Cassandra$get_range_slices_result.read(Cassandra.java:12422)
at com.rockmelt.org.apache.thrift.TServiceClient.receiveBase(TServiceClient.java:78)
at org.apache.cassandra.thrift.Cassandra$Client.recv_get_range_slices(Cassandra.java:696)
at org.apache.cassandra.thrift.Cassandra$Client.get_range_slices(Cassandra.java:680)
at org.apache.cassandra.hadoop.ColumnFamilyRecordReader$StaticRowIterator.maybeInit(ColumnFamilyRecordReader.java:362)
... 16 more

In ColumnFamilyRecordReader#initialize, a TBinaryProtocol is created as follows:

TTransport transport = ConfigHelper.getInputTransportFactory(conf).openTransport(socket, conf);
TBinaryProtocol binaryProtocol = new TBinaryProtocol(transport, ConfigHelper.getThriftMaxMessageLength(conf));
client = new Cassandra.Client(binaryProtocol);

But each time a call to cassandra is made, checkReadLength(int length) is called in TBinaryProtocol, which includes this:

readLength_ -= length;
if (readLength_ < 0) {
throw new TException("Message length exceeded: " + length);
}

The result is that readLength_ is decreased each time, until it goes negative and exception is thrown. This will only happen if you're reading a lot of data and your split size is large (which is maybe why people haven't noticed it earlier). This happens regardless of whether you use wide row support.

I'm not sure what the right fix is. It seems like you could either reset the length of TBinaryProtocol after each call or just use a new TBinaryProtocol each time.