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Philip (flip) Kromer edited comment on CASSANDRA-1434 at 8/30/10 5:38 AM: -------------------------------------------------------------------------- The blocking behavior is causing 'broken pipe' errors (even with relatively small batch sizes) when cassandra latency is high. (This is afaict not network latency but response latency due to a compaction or flush, etc.) It also makes the whole cluster resonate: one slow node blocks many writers, which then all unblock at the same time, write bursts of enough size to cause a compaction or GC, etc simultaneously on every node. This means adding more writers doesn't work around the blocking write was (Author: mrflip): The blocking behavior is causing 'broken pipe' errors (even with relatively small batch sizes) when cassandra latency is high. It also makes the whole cluster resonate: one slow node blocks many writers, which then all unblock at the same time, write bursts of enough size to cause a compaction or GC, etc simultaneously on every node. This means adding more writers doesn't work around the blocking write > ColumnFamilyOutputFormat performs blocking writes for large batches > ------------------------------------------------------------------- > > Key: CASSANDRA-1434 > URL: https://issues.apache.org/jira/browse/CASSANDRA-1434 > Project: Cassandra > Issue Type: Bug > Components: Hadoop > Reporter: Stu Hood > Fix For: 0.7.0 > > > By default, ColumnFamilyOutputFormat batches > {{mapreduce.output.columnfamilyoutputformat.batch.threshold}} or > {{Long.MAX_VALUE}} mutations, and then performs a blocking write. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.