Cassandra is a scalable and fault-tolerant NoSQL database system. For more information visit http://cassandra.apache.org/.
Even if the Cassandra plugin is not configured, Stackdriver Monitoring discovers Cassandra services running in your Cloud Platform project by:
- searching instance names for cassandra
- checking for ports opened to 9160 via firewall rules
The services discovered are displayed on the Cassandra Services page in the Resources menu. After you install the Monitoring agent and configure the Cassandra plugin on your instances, Monitoring populates the Cassandra Services page with inventory and metrics.
Configuring Monitoring to monitor Cassandra
After you install the Monitoring agent,
use the following instructions to configure the Cassandra plugin on your
instances. For instructions on upgrading from the legacy
go to Upgrading from jmxtrans.
The Cassandra plugin requires version 5.5.0-257 or later of the Monitoring agent. To update the agent, go to Upgrading the agent.
Enabling the Cassandra monitoring plugin
Cassandra is monitored via JMX. Monitoring has separate configurations for monitoring Cassandra versions 2.1.x and below, and versions 2.2.x and above.
On your VM instance, download the appropriate configuration file from the
GitHub configuration repository
based on your Cassandra version
and place it in the directory
(cd /opt/stackdriver/collectd/etc/collectd.d/ && curl -O https://raw.githubusercontent.com/Stackdriver/stackdriver-agent-service-configs/master/etc/collectd.d/cassandra-22.conf)
(cd /opt/stackdriver/collectd/etc/collectd.d/ && curl -O https://raw.githubusercontent.com/Stackdriver/stackdriver-agent-service-configs/master/etc/collectd.d/cassandra.conf)
The downloaded plugin configuration file assumes that your Cassandra instance is configured to accept JMX connections on port 7199. If you have configured Cassandra with a different JMX port, edit the file and follow the instructions to change the JMX port settings.
After adding the configuration file, restart the monitoring agent by running the following command:
sudo service stackdriver-agent restart
Information on other plugin configuration options can be found at collectd.org.
What is monitored
The Cassandra plugin monitors the following metrics:
- Storage Load: The amount of data stored on each Cassandra node.
- Pending Tasks: The number of basic task stages waiting to run.
- Active Tasks: The number of basic task stages currently running.
- Blocked Tasks: The number of basic task stages blocked from running.
- Pending Internal Tasks: The number of internal task stages waiting to run.
- Active Internal Tasks: The number of internal task stages currently running.
Monitoring also monitors the following basic JVM metrics:
- Active JVM Threads
- JVM Heap memory usage
- JVM Non-Heap memory usage
- JVM Open File Descriptors
- JVM Garbage Collection Count
Upgrading from jmxtrans
If you are currently running a VM with the legacy
you need to upgrade all of the Java-based plugins, namely
Tomcat. After you've upgraded those plugins
and restarted the
stackdriver-agent service, you can shut down the
process. You can then uninstall
jmxtrans by removing the
tree and the
/etc/init.d/jmxtrans script (if the script is present).