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The "StorageConfiguration" page has been changed by JonHermes. http://wiki.apache.org/cassandra/StorageConfiguration?action=diff&rev1=37&rev2=38 -------------------------------------------------- ||''-Dcassandra.config=file:///home/me/external-local-cassandra.yaml'' ||loads a local configuration file that is not located in the cassandra classpath. || - - == "Where are my keyspaces?" == LiveSchemaUpdates. You can load the schema once by using: {{{ bin/schematool HOST PORT import }}} + = Config Overview = Not going to cover every value, just the interesting ones. When in doubt, check out the comments on the default cassandra.yaml as they're well documented there. @@ -76, +75 @@ a. isInSameDataCenter: Look at the IP Address of the two hosts. Compare the 2nd octet. If they are the same then the hosts are in the same datacenter else different datacenter. - Dynamic Snitch is a boolean that controls the above snitch is wrapped with a dynamic snitch, which will monitor read latencies and avoid reading from hosts that have slowed. + Dynamic Snitch is a boolean that controls if the above snitch is wrapped with a dynamic snitch, which will monitor read latencies and avoid reading from hosts that have slowed. Defaults are: 'org.apache.cassandra.locator.SimpleSnitch' and 'false'. @@ -118, +117 @@ * '''thrift_framed_transport_size_in_mb''' - Setting this to '0' is how to denote using unframed (Buffered) transport. + Setting this to '0' is how to denote using unframed (Buffered) transport, and a nonzero value for framed transport. Default is: '15' mb. @@ -161, +160 @@ Default is: '864000' seconds, or 10 days. * '''keys_cached''' and '''rows_cached''' + Determines how many keys and rows to cache. The values can either be an absolute ('200000') or a double 0 <= d <= 1 ('0.52' for 52% cached). + + Each key cache hit saves 1 seek and each row cache hit saves 2 seeks at the minimum, sometimes more. The key cache is fairly tiny for the amount of time it saves, so it's worthwhile to use it at large numbers all the way up to 1.0 (all keys cached). The row cache saves even more time, but must store the whole values of its rows, so it is extremely space-intensive. It's best to only use the row cache if you have hot rows or static rows. Defaults are: '200000' keys cached, and '0', disabled row cache. * '''preload_row_cache''' + Attempts to populate the row cache on start up with sequential reads. Despite the improvement over random seeks during runtime, this can still take a fairly long time if the row cache to fill is massive. + + Default is: 'false'. * '''read_repair_chance''' + Before 0.7, read_repair was either invoked on every read request or on none of them. This is now tunable as a double 0 <= d <= 1 for the chance of invoking the repair. + + Default is: '1.0', read repair on every read request. * '''default_validation_class''' - Used in conjunction with the validation_class property in the per-column settings to guarantee the + Used in conjunction with the validation_class property in the per-column settings to guarantee the type of a column value. Default is: 'BytesType', a no-op. == per-Column Settings == + * '''index_name''' and '''index_type''' + * '''validation_class''' - * '''index_type''' -
