minor compaction vs. major compaction
min compaction threshold vs. max compaction threshold
问题一、
minor compaction vs. major compaction
1.major compaction 只能手动的通过nodetool触发,对整个column family所有的sstable进行compact;minor compcation通过配置参数min compaction threshold 和max compaction threashold达到条件后触发
2.在0.7-beta2版本之后,non-major compation 在比较bloom filter确认tombstone标示的row不存在于其它sstable中也可以将其删除。
因为minor compaction会根据min compaction threshold 和max compaction threashold对文件进行合并,并不一定会对CF所有的SSTABLE合并,所以不保证会删除所有的tombstone.
<!--
(0.7-beta2 --add by wm)
* remove tombstones during non-major compactions when bloom filter //如果在其他节点还有呢???
verifies that row does not exist in other sstables (CASSANDRA-1074)
-->
问题二、
min compaction threshold vs. max compaction threshold
1.compaction threshold 有两种设置方式
一种是使用JMX和nodetool设置,这个设置方式不是持久的,下次启动后失效;并且只对当前节点生效,不会扩散到集群中的其它节点。
#nodetool -h localhost setcompactionthreshold Keyspace1 Standard1 0 0
另一种方式是使用cli,这种配置是持久的,而且会扩展到其它节点。
cli>update column family X with min_compaction_threshold=Y and max_compaction_threshold=X
2.
- min_compaction_threshold: Avoid minor compactions of less than this number of sstable files
- max_compaction_threshold: Compact no more than this number of sstable files at once[@more@]
min compaction threshold vs. max compaction threshold
问题一、
minor compaction vs. major compaction
1.major compaction 只能手动的通过nodetool触发,对整个column family所有的sstable进行compact;minor compcation通过配置参数min compaction threshold 和max compaction threashold达到条件后触发
2.在0.7-beta2版本之后,non-major compation 在比较bloom filter确认tombstone标示的row不存在于其它sstable中也可以将其删除。
因为minor compaction会根据min compaction threshold 和max compaction threashold对文件进行合并,并不一定会对CF所有的SSTABLE合并,所以不保证会删除所有的tombstone.
<!--
(0.7-beta2 --add by wm)
* remove tombstones during non-major compactions when bloom filter //如果在其他节点还有呢???
verifies that row does not exist in other sstables (CASSANDRA-1074)
-->
问题二、
min compaction threshold vs. max compaction threshold
1.compaction threshold 有两种设置方式
一种是使用JMX和nodetool设置,这个设置方式不是持久的,下次启动后失效;并且只对当前节点生效,不会扩散到集群中的其它节点。
#nodetool -h localhost setcompactionthreshold Keyspace1 Standard1 0 0
另一种方式是使用cli,这种配置是持久的,而且会扩展到其它节点。
cli>update column family X with min_compaction_threshold=Y and max_compaction_threshold=X
2.
- min_compaction_threshold: Avoid minor compactions of less than this number of sstable files
- max_compaction_threshold: Compact no more than this number of sstable files at once[@more@]
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