= cassandra-env.sh file

The `cassandra-env.sh` bash script file can be used to pass additional
options to the Java virtual machine (JVM), such as maximum and minimum
heap size, rather than setting them in the environment. If the JVM
settings are static and do not need to be computed from the node
characteristics, the `cassandra-jvm-options` files should be used
instead. For example, commonly computed values are the heap sizes, using
the system values.

For example, add
`JVM_OPTS="$JVM_OPTS -Dcassandra.load_ring_state=false"` to the
`cassandra_env.sh` file and run the command-line `cassandra` to start.
The option is set from the `cassandra-env.sh` file, and is equivalent to
starting Cassandra with the command-line option
`cassandra -Dcassandra.load_ring_state=false`.

The `-D` option specifies the start-up parameters in both the command
line and `cassandra-env.sh` file. The following options are available:

== `cassandra.auto_bootstrap=false`

Facilitates setting auto_bootstrap to false on initial set-up of the
cluster. The next time you start the cluster, you do not need to change
the `cassandra.yaml` file on each node to revert to true, the default
value.

== `cassandra.available_processors=<number_of_processors>`

In a multi-instance deployment, multiple Cassandra instances will
independently assume that all CPU processors are available to it. This
setting allows you to specify a smaller set of processors.

== `cassandra.config=<directory>`

The directory location of the `cassandra.yaml file`. The default
location depends on the type of installation.

== `cassandra.ignore_dynamic_snitch_severity=true|false`

Setting this property to true causes the dynamic snitch to ignore the
severity indicator from gossip when scoring nodes. Explore failure
detection and recovery and dynamic snitching for more information.

*Default:* false

== `cassandra.initial_token=<token>`

Use when virtual nodes (vnodes) are not used. Sets the initial
partitioner token for a node the first time the node is started. Note:
Vnodes are highly recommended as they automatically select tokens.

*Default:* disabled

== `cassandra.join_ring=true|false`

Set to false to start Cassandra on a node but not have the node join the
cluster. You can use `nodetool join` and a JMX call to join the ring
afterwards.

*Default:* true

== `cassandra.load_ring_state=true|false`

Set to false to clear all gossip state for the node on restart.

*Default:* true

== `cassandra.partitioner=<partitioner>`

Set the partitioner.

*Default:* org.apache.cassandra.dht.Murmur3Partitioner

== `cassandra.prepared_statements_cache_size_in_bytes=<cache_size>`

Set the cache size for prepared statements.

== `cassandra.replace_address=<listen_address of dead node>|<broadcast_address of dead node>`

To replace a node that has died, restart a new node in its place
specifying the `listen_address` or `broadcast_address` that the new node
is assuming. The new node must not have any data in its data directory,
the same state as before bootstrapping. Note: The `broadcast_address`
defaults to the `listen_address` except when using the
`Ec2MultiRegionSnitch`.

== `cassandra.replayList=<table>`

Allow restoring specific tables from an archived commit log.

== `cassandra.ring_delay_ms=<number_of_ms>`

Defines the amount of time a node waits to hear from other nodes before
formally joining the ring.

*Default:* 1000ms

== `cassandra.native_transport_port=<port>`

Set the port on which the CQL native transport listens for clients.

*Default:* 9042

== `cassandra.rpc_port=<port>`

Set the port for the Thrift RPC service, which is used for client
connections.

*Default:* 9160

== `cassandra.storage_port=<port>`

Set the port for inter-node communication.

*Default:* 7000

== `cassandra.ssl_storage_port=<port>`

Set the SSL port for encrypted communication.

*Default:* 7001

== `cassandra.start_native_transport=true|false`

Enable or disable the native transport server. See
`start_native_transport` in `cassandra.yaml`.

*Default:* true

== `cassandra.start_rpc=true|false`

Enable or disable the Thrift RPC server.

*Default:* true

== `cassandra.triggers_dir=<directory>`

Set the default location for the trigger JARs.

*Default:* conf/triggers

== `cassandra.write_survey=true`

For testing new compaction and compression strategies. It allows you to
experiment with different strategies and benchmark write performance
differences without affecting the production workload.

== `consistent.rangemovement=true|false`

Set to true makes Cassandra perform bootstrap safely without violating
consistency. False disables this.
