ERROR Message Example
ERROR 10:26:07 Fatal error parsing partition: aye org.codehaus.jackson.JsonGenerationException: Can not start an object, expecting field name
TYPICALLY WOULD PRODUCE A STACK TRACE SIMILAR TO THE FOLLOWING:
org.codehaus.jackson.JsonGenerationException: Can not start an object, expecting field name at org.codehaus.jackson.impl.JsonGeneratorBase._reportError(JsonGeneratorBase.java:480) ~[jackson-core-asl-1.9.2.jar:1.9.2] at org.codehaus.jackson.impl.WriterBasedGenerator._verifyValueWrite(WriterBasedGenerator.java:836) ~[jackson-core-asl-1.9.2.jar:1.9.2] at org.codehaus.jackson.impl.WriterBasedGenerator.writeStartObject(WriterBasedGenerator.java:273) ~[jackson-core-asl-1.9.2.jar:1.9.2] at org.apache.cassandra.tools.JsonTransformer.serializePartition(JsonTransformer.java:181) ~[main/:na] at java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:184) ~[na:1.8.0_77] at java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:175) ~[na:1.8.0_77] at java.util.Iterator.forEachRemaining(Iterator.java:116) ~[na:1.8.0_77] at java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801) ~[na:1.8.0_77] at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481) ~[na:1.8.0_77] at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471) ~[na:1.8.0_77] at java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:151) ~[na:1.8.0_77] at java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:174) ~[na:1.8.0_77] at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) ~[na:1.8.0_77] at java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:418) ~[na:1.8.0_77] at org.apache.cassandra.tools.JsonTransformer.toJson(JsonTransformer.java:99) ~[main/:na] at org.apache.cassandra.tools.SSTableExport.main(SSTableExport.java:237) ~[main/:na]
What does this ERROR message mean?
This error means when serializing a partition from a sstable, Cassandra has encountered an IOException, this error message would print out the partition key that has encountered the exception, and the IOException itself.
Why does this ERROR occur
This issue is caused by a bug in old versions of Cassandra when serializing a partition and encounters a partition level deletion. The reported Jira is https://issues.apache.org/jira/browse/CASSANDRA-12418 , where function serializePartition(UnfilteredRowIterator partition) has a misplaced call of function json.writeEndObject()
In problematic code:
private void serializePartition(UnfilteredRowIterator partition)
{
...
try
{
json.writeStartObject();
...
json.writeStartObject();
...
if (!partition.partitionLevelDeletion().isLive())
{
serializeDeletion(partition.partitionLevelDeletion());
}
else
{
json.writeEndObject();
...
}
json.writeEndObject();
...
}
so there are 2 calls of function json.writeStartObject(), thus there should be 2 calls of function json.writeEndObject(). However, the first call of json.writeEndObject() is placed in the else condition, so when the if condition !partition.partitionLevelDeletion().isLive() is satisfied, it will skip this first call of function json.writeEndObject() and thus lead to this error.
In the code fix, the else condition has been removed, and the first call of json.writeEndObject() has been placed right after the if condition, so 2 calls of json.writeEndObject() would be executed.
private void serializePartition(UnfilteredRowIterator partition)
{
try
{
json.writeStartObject();
...
json.writeStartObject();
...
if (!partition.partitionLevelDeletion().isLive())
serializeDeletion(partition.partitionLevelDeletion());
json.writeEndObject();
...
json.writeEndObject();
}
...
}
How to fix it?
This issue is fixed in cassandra version 3.0.9 and 3.11.1 and later versions, so you would need to upgrade to these and later versions to overcome this issue.