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The "StorageConfiguration" page has been changed by JonHermes. http://wiki.apache.org/cassandra/StorageConfiguration?action=diff&rev1=26&rev2=27 -------------------------------------------------- == per-Cluster (Global) Settings == === authenticator === + Allows for pluggable authentication of users, which defines whether it is necessary to call the Thrift 'login' method, and which parameters are required to login. The default '!AllowAllAuthenticator' does not require users to call 'login': any user can perform any operation. The other built in option is '!SimpleAuthenticator', which requires users and passwords to be defined in property files, and for users to call login with a valid combo. + - org.apache.cassandra.auth.AllowAllAuthenticator + Default is: 'org.apache.cassandra.auth.AllowAllAuthenticator', a no-op. === auto_bootstrap === - false + Set to 'true' to make new [non-seed] nodes automatically migrate the right data to themselves. (If no InitialToken is specified, they will pick one such that they will get half the range of the most-loaded node.) If a node starts up without bootstrapping, it will mark itself bootstrapped so that you can't subsequently accidently bootstrap a node with data on it. (You can reset this by wiping your data and commitlog directories.) + + Off by default so that new clusters don't bootstrap immediately. You should turn this on when you start adding new nodes to a cluster that already has data on it. === cluster_name === - Cluster + The name of this cluster. This is mainly used to prevent machines in one logical cluster from joining another. === commitlog_directory === /var/lib/cassandra/commitlog @@ -51, +55 @@ false === endpoint_snitch === - org.apache.cassandra.locator.RackInferringSnitch + !EndPointSnitch: Setting this to the class that implements {{{IEndPointSnitch}}} which will see if two endpoints are in the same data center or on the same rack. Out of the box, Cassandra provides {{{org.apache.cassandra.locator.RackInferringSnitch}}} - === hinted_handoff_enabled === - true + Note: this class will work on hosts' IPs only. There is no configuration parameter to tell Cassandra that a node is in rack ''R'' and in datacenter ''D''. The current rules are based on the two methods: + + * isOnSameRack: Look at the IP Address of the two hosts. Compare the 3rd octet. If they are the same then the hosts are in the same rack else different racks. + + * 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. === memtable_flush_after_mins === === memtable_operations_in_millions === @@ -68, +75 @@ 10000 === seeds === - LIST {"127.0.0.1",} + Never use a node's own address as a seed if you are bootstrapping it by setting autobootstrap to true! === thrift_framed_transport_size_in_mb === 15 by default. Setting this to 0 is how to denote using unframed transport. @@ -76, +83 @@ == per-Keyspace Settings == == per-ColumnFamily Settings == == per-Column Settings == - == AutoBootstrap == - ''[New in 0.5:'' - Turn on to make new [non-seed] nodes automatically migrate the right data to themselves. (If no InitialToken is specified, they will pick one such that they will get half the range of the most-loaded node.) If a node starts up without bootstrapping, it will mark itself bootstrapped so that you can't subsequently accidently bootstrap a node with data on it. (You can reset this by wiping your data and commitlog directories.) - Off by default so that new clusters and upgraders from 0.4 don't bootstrap immediately. You should turn this on when you start adding new nodes to a cluster that already has data on it. (If you are upgrading from 0.4, start your cluster with it off once before changing it to true. Otherwise, no data will be lost but you will incur a lot of unnecessary I/O before your cluster starts up.) - {{{ - <AutoBootstrap>false</AutoBootstrap> - }}} - '']'' - - == Cluster Name == - The name of this cluster. This is mainly used to prevent machines in one logical cluster from joining another. - - Example: - - {{{ - <ClusterName>Test Cluster</ClusterName> - }}} - == Authenticator == - ''[New in 0.6:'' - - Allows for pluggable authentication of users, which defines whether it is necessary to call the Thrift 'login' method, and which parameters are required to login. The default '!AllowAllAuthenticator' does not require users to call 'login': any user can perform any operation. The other built in option is '!SimpleAuthenticator', which requires users and passwords to be defined in property files, and for users to call login with a valid combo. - - Example: - - {{{ - <Authenticator>org.apache.cassandra.auth.SimpleAuthenticator</Authenticator> - }}} - '']'' == Keyspaces and ColumnFamilies == Keyspaces and {{{ColumnFamilies}}}: A {{{ColumnFamily}}} is the Cassandra concept closest to a relational table. {{{Keyspaces}}} are separate groups of {{{ColumnFamilies}}}. Except in very unusual circumstances you will have one Keyspace per application. @@ -127, +106 @@ '']'' ''[New in 0.6: !EndPointSnitch, !ReplicaPlacementStrategy and !ReplicationFactor became configurable per keyspace. Prior to that they were global settings.]'' - - === EndPointSnitch === - !EndPointSnitch: Setting this to the class that implements {{{IEndPointSnitch}}} which will see if two endpoints are in the same data center or on the same rack. Out of the box, Cassandra provides {{{org.apache.cassandra.locator.EndPointSnitch}}} - - {{{ - <EndPointSnitch>org.apache.cassandra.locator.EndPointSnitch</EndPointSnitch> - }}} - Note: this class will work on hosts' IPs only. There is no configuration parameter to tell Cassandra that a node is in rack ''R'' and in datacenter ''D''. The current rules are based on the two methods: (see [[http://svn.apache.org/viewvc/incubator/cassandra/trunk/src/java/org/apache/cassandra/locator/EndPointSnitch.java?view=markup|EndPointSnitch.java]]): - - * isOnSameRack: Look at the IP Address of the two hosts. Compare the 3rd octet. If they are the same then the hosts are in the same rack else different racks. - - * 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. === ReplicaPlacementStrategy and ReplicationFactor === Strategy: Setting this to the class that implements {{{IReplicaPlacementStrategy}}} will change the way the node picker works. Out of the box, Cassandra provides {{{org.apache.cassandra.locator.RackUnawareStrategy}}} and {{{org.apache.cassandra.locator.RackAwareStrategy}}} (place one replica in a different datacenter, and the others on different racks in the same one.) @@ -205, +172 @@ With {{{OrderPreservingPartitioner}}} the keys themselves are used to place on the ring. One of the potential drawback of this approach is that if rows are inserted with sequential keys, all the write load will go to the same node. - == Directories == - Directories: Specify where Cassandra should store different data on disk. Keep the data disks and the {{{CommitLog}}} disks separate for best performance. See also [[FAQ#what_kind_of_hardware_should_i_use|what kind of hardware should I use?]] - - {{{ - <CommitLogDirectory>/var/lib/cassandra/commitlog</CommitLogDirectory> - <DataFileDirectories> - <DataFileDirectory>/var/lib/cassandra/data</DataFileDirectory> - </DataFileDirectories> - }}} - == Seeds == - Addresses of hosts that are deemed contact points. Cassandra nodes use this list of hosts to find each other and learn the topology of the ring. You must change this if you are running multiple nodes! - - {{{ - <Seeds> - <Seed>127.0.0.1</Seed> - </Seeds> - }}} - Never use a node's own address as a seed if you are bootstrapping it by setting AutoBootstrap to true. == Miscellaneous == Time to wait for a reply from other nodes before failing the command
