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diff --git a/charms/trusty/cassandra/README.md b/charms/trusty/cassandra/README.md deleted file mode 100644 index 00784cc..0000000 --- a/charms/trusty/cassandra/README.md +++ /dev/null @@ -1,179 +0,0 @@ -# Overview - -The Apache Cassandra database is the right choice when you need scalability -and high availability without compromising performance. Linear scalability -and proven fault-tolerance on commodity hardware or cloud infrastructure -make it the perfect platform for mission-critical data. Cassandra's support -for replicating across multiple datacenters is best-in-class, providing lower -latency for your users and the peace of mind of knowing that you can survive -regional outages. - -See [cassandra.apache.org](http://cassandra.apache.org) for more information. - - -# Editions - -This charm supports Apache Cassandra 2.0, 2.1, 2.2 & 3.0, and -Datastax Enterprise 4.7 & 4.8. The default is Apache Cassandra 2.2. - -To use Apache Cassandra 2.0, specify the Apache Cassandra 2.0 archive source -in the `install_sources` config setting when deploying. - -To use Datastax Enterprise, set the `edition` config setting to `dse` -and the Datastax Enterprise archive URL in `install_sources` (including your -username and password). - - -# Deployment - -Cassandra deployments are relatively simple in that they consist of a set of -Cassandra nodes which seed from each other to create a ring of servers: - - juju deploy -n3 cs:trusty/cassandra - -The service units will deploy and will form a single ring. - -New nodes can be added to scale up: - - juju add-unit cassandra - - -/!\ Nodes must be manually decommissioned before dropping a unit. - - juju run --unit cassandra/1 "nodetool decommission" - # Wait until Mode is DECOMMISSIONED - juju run --unit cassandra/1 "nodetool netstats" - juju remove-unit cassandra/1 - -It is recommended to deploy at least 3 nodes and configure all your -keyspaces to have a replication factor of three. Using fewer nodes or -neglecting to set your keyspaces' replication settings means that your -data is at risk and availability lower, as a failed unit may take the -only copy of data with it. - -Production systems will normally want to set `max_heap_size` and -`heap_newsize` to the empty string, to enable automatic memory size -tuning. The defaults have been chosen to be suitable for development -environments but will perform poorly with real workloads. - - -## Planning - -- Do not attempt to store too much data per node. If you need more space, - add more nodes. Most workloads work best with a capacity under 1TB - per node. - -- You need to keep 50% of your disk space free for Cassandra maintenance - operations. If you expect your nodes to hold 500GB of data each, you - will need a 1TB partition. Using non-default compaction such as - LeveledCompactionStrategy can lower this waste. - -- Much more information can be found in the [Cassandra 2.2 documentation](http://docs.datastax.com/en/cassandra/2.2/cassandra/planning/planPlanningAbout.html) - - -## Network Access - -The default Cassandra packages are installed from the apache.org -archive. To avoid this download, place a copy of the packages in a local -archive and specify its location in the `install_sources` configuration -option. The signing key is automatically added. - -When using DataStax Enterprise, you need to specify the archive location -containing the DataStax Enterprise .deb packages in the -`install_sources` configuration item, and the signing key in the -`install_keys` configuration item. Place the DataStax packages in a -local archive to avoid downloading from datastax.com. - - -## Oracle Java SE - -Cassandra recommends using Oracle Java SE 8. Unfortunately, this -software is accessible only after accepting Oracle's click-through -license making deployments using it much more cumbersome. You will need -to download the Oracle Java SE 8 Server Runtime for Linux, and place the -tarball at a URL accessible to your deployed units. The config item -`private_jre_url` needs to be set to this URL. - - -# Usage - -To relate the Cassandra charm to a service that understands how to talk to -Cassandra using Thrift or the native Cassandra protocol:: - - juju deploy cs:service-that-needs-cassandra - juju add-relation service-that-needs-cassandra cassandra:database - - -Alternatively, if you require a superuser connection, use the -`database-admin` relation instead of `database`:: - - juju deploy cs:admin-service - juju add-relation admin-service cassandra:database-admin - - -Client charms need to provide nothing. The Cassandra service publishes the -following connection settings and cluster information on the client's relation: - -`username` and `password`: - - Authentication credentials. The cluster is configured to use - the standard PasswordAuthenticator authentication provider, rather - than the insecure default. You can use different credentials - if you wish, using an account created through some other mechanism. - -`host`: - - IP address to connect to. - -`native_transport_port`: - - Port for drivers and tools using the newer native protocol. - -`rpc_port`: - - Port for drivers and tools using the legacy Thrift protocol. - -`cluster_name`: - - The cluster name. A client service may be related to several - Cassandra services, and this setting may be used to tell which - services belong to which cluster. - -`datacenter` and `rack`: - - The datacenter and rack units in this service belong to. Required for - setting keyspace replication correctly. - -The cluster is configured to use the recommended 'snitch' -(GossipingPropertyFileSnitch), so you will need to configure replication of -your keyspaces using the NetworkTopologyStrategy replica placement strategy. -For example, using the default datacenter named 'juju': - - CREATE KEYSPACE IF NOT EXISTS mydata WITH REPLICATION = - { 'class': 'NetworkTopologyStrategy', 'juju': 3}; - - -Although authentication is configured using the standard -PasswordAuthentication, by default no authorization is configured -and the provided credentials will have access to all data on the cluster. -For more granular permissions, you will need to set the authorizer -in the service configuration to CassandraAuthorizer and manually grant -permissions to the users. - - -# Known Limitations and Issues - -This is the 'trusty' charm. Upgrade from the 'precise' charm is not supported. - -The `system_auth` keyspace replication factor is automatically increased -but not decreased. If you have a service with three or more units and -decommission enough nodes to drop below three, you will need to manually -update the `system_auth` keyspace replication settings. - - -# Contact Information - -## Cassandra - -- [Apache Cassandra homepage](http://cassandra.apache.org/) -- [Cassandra Getting Started](http://wiki.apache.org/cassandra/GettingStarted) |