DataStax Agent configuration

Agent autoconnect

If you are using OpsCenter to provision a cluster, agent autoconnection should work with no need to alter the configuration of the agent. In this case, OpsCenter installs the agent on each node and then uses the agent to install Cassandra or DSE.

If you are adding an existing cluster to OpsCenter, and the nodes do not have the agent installed, OpsCenter will display a Fix Agents link next to the number of nodes. Clicking Fix Agents will cause OpsCenter to attempt to install and start the agent on any nodes that do not have a running agent, as described in Automatic installation of DataStax agents and Installing DataStax agents.

If clicking Fix Agents doesn't work, there are a number of things that could prevent OpsCenter from successfully installing and starting the agent on the nodes. For example, if the agent was previously installed on the node and has an incorrect configuration, OpsCenter will not be able to connect to the agent. Some simple things to check if the agent fails to connect are:

That the agent is able to start up without errors on the node. Look through the agent logs for errors.
The settings of the stomp_interface and stomp_port options for each agent, to make sure they match they are pointing at the OpsCenter host and port, respectively.
That the OpsCenter host and port are accessible from the node. For example, a firewall may block access to the OpsCenter port.
If you've configured OpsCenter to use SSL communication between OpsCenter and the agents, but the agents do not have the correct configuration settings for SSL communication.
That the SSH credentials you've entered in OpsCenter work on each node.
That JMX connectivity is enabled on the node.

The address.yaml configuration file

The address.yaml file contains configuration options for the DataStax Agent.

address.yaml

The location of the address.yaml file depends on the type of installation:

Package installations: /var/lib/datastax-agent/conf/address.yaml
Tarball installations: install_location/conf/address.yaml

opscenterd.conf

The location of the opscenterd.conf file depends on the type of installation:

Location	Package	Installer (GUI or text mode)		Tarball
Location	Package	Service	No-service	Tarball
/etc/opscenter/opscenterd.conf	X	X
`install_location`/conf/opscenterd.conf			X	X

Options

stomp_interface: Reachable IP address of the opscenterd machine. The connection made will be on stomp_port
stomp_port: The stomp_port used by opscenterd. The default setting is 61620.
local_interface: The IP used to identify the node. If broadcast_address is set in cassandra.yaml, this should be the same as that; otherwise, it is typically the same as listen_address in cassandra.yaml. A good check is to confirm that this address is the same as the address that nodetool ring outputs.
agent_rpc_interface: The IP that the agent HTTP server listens on. In a multiple region deployment, this is typically a private IP.
agent_rpc_broadcast_address: The IP that the central OpsCenter process uses to connect to the DataStax agent.
use_ssl: Whether or not to use SSL communication between the agent and opscenterd. Affects both the STOMP connection and agent HTTP server. Corresponds to [agents].use_ssl in opscenterd.conf. Setting this option to true turns on SSL connections. The default setting is 0.
cassandra_conf: The agent will attempt to auto-detect the location of the cassandra.yaml file via JMX, but if it cannot this needs to be set to the full path of cassandra.yaml. By default /etc/cassandra/cassandra.yaml on package installs or <install_location>/conf/cassandra.yaml on tarball installs.
cassandra_install_location: The location where Cassandra is installed for tarball installs if OpsCenter is unable to auto-detect the install location.
cassandra_log_location: The location of Cassandra's system.log file. This is only used for the diagnostics tarball, and should only be set if system.log is in a non-standard location.

Advanced options

metrics_enabled: Whether or not to collect and store metrics for the local node. Setting this option to false turns off metrics collection. The default setting is true.
thrift_port: Port used to connect to local thrift server. The default setting is 9160. This information will be sent by opscenterd for convenience, but can be configured locally as needed.
jmx_host: Host used to connect to local JMX server. The default setting is localhost. This information will be sent by opscenterd for convenience, but can be configured locally as needed.
jmx_port: Port used to connect to local JMX server. The default setting is 7199. This information will be sent by opscenterd for convenience, but can be configured locally as needed.
api_port: Port the local HTTP server will bind to. The default setting is 61621. This option needs to be identical across all agents, and set explicitly in opscenterd.conf if changed.

runs_sudo: Sets whether the DataStax Agent will be run using sudo or not. Setting this option to false means the agent will not use sudo, and the agent user will not run using elevated privileges. Setting this option to true means the agent will run using sudo, and elevated privileges.; The default setting is true.