The docs for the CLI say: - min_compaction_threshold: The minimum number of SSTables needed to start a minor compaction. Default is 4, setting to 0 disables minor compactions.
If you are getting an error using 0 can you please raise a ticket on https://issues.apache.org/jira/browse/CASSANDRA (Also you can also set the compaction threshold on a single node via nodetool. ) Thanks ----------------- Aaron Morton Freelance Developer @aaronmorton http://www.thelastpickle.com On 18/05/2012, at 3:09 PM, Vijay wrote: > I would rather set the Keyspace setting min_compaction_threshold and > max_compaction_threshold to be a higher number and once i am ready i will put > the value back... This way i dont need to restart. > Having said that why not set the compaction throughput to 1 (low enough to > not have contention) and complete the stream? > > Regards, > </VJ> > > > > On Wed, May 16, 2012 at 2:43 PM, sj.climber <sj.clim...@gmail.com> wrote: > Hi, > > In an effort to minimize IO contention, I'd like to disable compactions > while I'm streaming SSTables to the cluster. When done streaming, I intend > on forcing a major compaction through nodetool. > > Elsewhere in the forums, various folks suggest setting > max_compaction_threshold = 0 to disable compaction. While this works > sometimes (via 'update column family <family> with > max_compaction_threshold=0'), I've observed a number of serious issues with > this approach: > > 1) You can't create a column family with max_compaction_threshold = 0. The > CLI reports that min_compaction_threshold must have a value >= 2, and > max_compaction_threshold can't be lower than it. Worse yet, trying to > create a column family with max_compaction_threshold = 0 gets the cluster > into a Schema Disagreement Exception (since the node on which you issue the > migration command fails with a fatal error). > > 2) Cassandra will allow me to update an existing column family with > max_compaction_threshold = 0. But if I restart the node, it will crash on > startup. > java.lang.reflect.InvocationTargetException > at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) > at > sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) > at > sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) > at java.lang.reflect.Method.invoke(Method.java:597) > at > org.apache.commons.daemon.support.DaemonLoader.load(DaemonLoader.java:160) > Caused by: java.lang.RuntimeException: > java.lang.reflect.InvocationTargetException > ... > org.apache.cassandra.config.CFMetaData.createCompactionStrategyInstance(CFMetaData.java:839) > ... 14 more > Caused by: java.lang.RuntimeException: The max_compaction_threshold cannot > be smaller than the min. > at > org.apache.cassandra.db.ColumnFamilyStore.setMaximumCompactionThreshold(ColumnFamilyStore.java:1740) > at org.apache. > > > Is there another solution for more safely enabling/disabling compaction? > > Thanks! > > -- > View this message in context: > http://cassandra-user-incubator-apache-org.3065146.n2.nabble.com/Safely-Disabling-Compaction-tp7562777.html > Sent from the cassandra-u...@incubator.apache.org mailing list archive at > Nabble.com. >
