cassandra-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Vadim Tsesko (JIRA)" <>
Subject [jira] [Commented] (CASSANDRA-11117) ColUpdateTimeDeltaHistogram histogram overflow
Date Tue, 27 Sep 2016 08:54:20 GMT


Vadim Tsesko commented on CASSANDRA-11117:

I tried to trace the problem using Cassandra 3.7.
The problematic value overflowing the histogram is added in the following stack trace:
	at org.apache.cassandra.utils.EstimatedHistogram.add( [apache-cassandra-3.7.jar:3.7]
	at org.apache.cassandra.metrics.EstimatedHistogramReservoir.update(
	at com.codahale.metrics.Histogram.update( [metrics-core-3.1.0.jar:3.1.0]
	at org.apache.cassandra.metrics.TableMetrics$TableHistogram.update(
	at org.apache.cassandra.db.ColumnFamilyStore.apply( [apache-cassandra-3.7.jar:3.7]
	at org.apache.cassandra.db.Keyspace.apply( [apache-cassandra-3.7.jar:3.7]
	at org.apache.cassandra.db.Keyspace.apply( [apache-cassandra-3.7.jar:3.7]
	at org.apache.cassandra.db.Mutation.applyFuture( [apache-cassandra-3.7.jar:3.7]
	at org.apache.cassandra.db.Mutation.apply( [apache-cassandra-3.7.jar:3.7]
	at org.apache.cassandra.db.Mutation.apply( [apache-cassandra-3.7.jar:3.7]
	at org.apache.cassandra.service.StorageProxy$8.runMayThrow( ~[apache-cassandra-3.7.jar:3.7]
	at org.apache.cassandra.service.StorageProxy$
	at java.util.concurrent.Executors$ ~[na:1.8.0_102]
	at org.apache.cassandra.concurrent.AbstractLocalAwareExecutorService$
	at org.apache.cassandra.concurrent.AbstractLocalAwareExecutorService$
	at ~[apache-cassandra-3.7.jar:3.7]
	at ~[na:1.8.0_102]
The problem is caused by using time interval in {{ColumnFamilyStore.apply()}} returned by
{{Memtable.put()}} which is calculated by {{Rows.merge()}} method. It seems that in case of
an update for a nonexisting row an *absolute* time value is returned, not time delta. That
leads to very large values being sent to the histogram (as large as {{Long.MAX_VALUE / 10}}
judging by debugging on real data).
We decided to patch Cassandra and to ignore the overflowed histogram values temporarily.

> ColUpdateTimeDeltaHistogram histogram overflow
> ----------------------------------------------
>                 Key: CASSANDRA-11117
>                 URL:
>             Project: Cassandra
>          Issue Type: Bug
>            Reporter: Chris Lohfink
>            Assignee: Joel Knighton
>            Priority: Minor
>             Fix For: 2.2.x, 3.0.x, 3.x
> {code}
> getting attribute Mean of org.apache.cassandra.metrics:type=ColumnFamily,name=ColUpdateTimeDeltaHistogram
threw an java.lang.IllegalStateException:
Unable to compute ceiling for max when histogram overflowed
> {code}
> Although the fact that this histogram has 164 buckets already, I wonder if there is something
weird with the computation thats causing this to be so large? It appears to be coming from
updates to system.local
> {code}
> org.apache.cassandra.metrics:type=Table,keyspace=system,scope=local,name=ColUpdateTimeDeltaHistogram
> {code}

This message was sent by Atlassian JIRA

View raw message