Apache Cassandra

The Apache Cassandra integration collects request, task, and storage metrics that highlight the load on an instance. Optionally, the integration can also collect general JVM metrics related to memory and garbage collection. The integration also collects system, debug, and garbage-collection logs. These logs are parsed into a JSON payload, which includes fields for the message, Java class, and line number.

For more information about Cassandra, see the Apache Cassandra documentation.

Prerequisites

To collect Cassandra telemetry, you must install the Ops Agent:

  • For metrics, install version 2.6.0 or higher.
  • For logs, install version 2.5.0 or higher.

This integration supports Cassandra versions 3.11 and 4.0.

Configure your Cassandra instance

To expose a JMX endpoint, you must set the com.sun.management.jmxremote.port system property when starting the JVM. We also recommend setting the com.sun.management.jmxremote.rmi.port system property to the same port. To expose a JMX endpoint remotely, you must also set the java.rmi.server.hostname system property.

By default, these properties are set in a Cassandra deployment's cassandra-env.sh file.

To set system properties by using command-line arguments, prepend the property name with -D when starting the JVM. For example, to set com.sun.management.jmxremote.port to port 7199, specify the following when starting the JVM:

-Dcom.sun.management.jmxremote.port=7199

Configure the Ops Agent for Cassandra

Following the guide to Configure the Ops Agent, add the required elements to collect telemetry from Cassandra instances, and restart the agent.

Example configuration

The following commands create the configuration to collect and ingest telemetry for Cassandra:

# Configures Ops Agent to collect telemetry from the app. You must restart the agent for the configuration to take effect.

set -e

# Check if the file exists
if [ ! -f /etc/google-cloud-ops-agent/config.yaml ]; then
  # Create the file if it doesn't exist.
  sudo mkdir -p /etc/google-cloud-ops-agent
  sudo touch /etc/google-cloud-ops-agent/config.yaml
fi

# Create a back up of the existing file so existing configurations are not lost.
sudo cp /etc/google-cloud-ops-agent/config.yaml /etc/google-cloud-ops-agent/config.yaml.bak

# Configure the Ops Agent.
sudo tee /etc/google-cloud-ops-agent/config.yaml > /dev/null << EOF
metrics:
  receivers:
    cassandra:
      type: cassandra
      endpoint: service:jmx:rmi:///jndi/rmi://127.0.0.1:7199/jmxrmi
  service:
    pipelines:
      cassandra:
        receivers:
          - cassandra
logging:
  receivers:
    cassandra_system:
      type: cassandra_system
    cassandra_debug:
      type: cassandra_debug
    cassandra_gc:
      type: cassandra_gc
  service:
    pipelines:
      cassandra:
        receivers:
          - cassandra_system
          - cassandra_debug
          - cassandra_gc
EOF

For these changes to take effect, you must restart the Ops Agent:

Linux

  1. To restart the agent, run the following command on your instance: 
    sudo systemctl restart google-cloud-ops-agent
  2. To confirm that the agent restarted, run the following command and verify that the components "Metrics Agent" and "Logging Agent" started: 
    sudo systemctl status "google-cloud-ops-agent*"

Windows

  1. Connect to your instance using RDP or a similar tool and login to Windows.
  2. Open a PowerShell terminal with administrator privileges by right-clicking the PowerShell icon and selecting Run as Administrator
  3. To restart the agent, run the following PowerShell command: 
    Restart-Service google-cloud-ops-agent -Force
  4. To confirm that the agent restarted, run the following command and verify that the components "Metrics Agent" and "Logging Agent" started: 
    Get-Service google-cloud-ops-agent*

Configure logs collection

To ingest logs from Cassandra, you must create a receiver for the logs that Cassandra produces and then create a pipeline for the new receiver.

To configure a receiver for your cassandra_system logs, specify the following fields:

Field Default Description
exclude_paths A list of filesystem path patterns to exclude from the set matched by include_paths.
include_paths [/var/log/cassandra/system*.log] A list of filesystem paths to read by tailing each file. A wild card (*) can be used in the paths; for example, /var/log/cassandra/system*.log.
record_log_file_path false If set to true, then the path to the specific file from which the log record was obtained appears in the output log entry as the value of the agent.googleapis.com/log_file_path label. When using a wildcard, only the path of the file from which the record was obtained is recorded.
type This value must be cassandra_system.
wildcard_refresh_interval 60s The interval at which wildcard file paths in include_paths are refreshed. Given as a time duration, for example 30s or 2m. This property might be useful under high logging throughputs where log files are rotated faster than the default interval.

To configure a receiver for your cassandra_debug logs, specify the following fields:

Field Default Description
exclude_paths A list of filesystem path patterns to exclude from the set matched by include_paths.
include_paths [/var/log/cassandra/debug*.log] A list of filesystem paths to read by tailing each file. A wild card (*) can be used in the paths; for example, /var/log/cassandra/system*.log.
record_log_file_path false If set to true, then the path to the specific file from which the log record was obtained appears in the output log entry as the value of the agent.googleapis.com/log_file_path label. When using a wildcard, only the path of the file from which the record was obtained is recorded.
type This value must be cassandra_debug.
wildcard_refresh_interval 60s The interval at which wildcard file paths in include_paths are refreshed. Given as a time duration, for example 30s or 2m. This property might be useful under high logging throughputs where log files are rotated faster than the default interval.

To configure a receiver for your cassandra_gc logs, specify the following fields:

Field Default Description
exclude_paths A list of filesystem path patterns to exclude from the set matched by include_paths.
include_paths [/var/log/cassandra/gc.log.*.current] A list of filesystem paths to read by tailing each file. A wild card (*) can be used in the paths; for example, /var/log/cassandra/system*.log.
record_log_file_path false If set to true, then the path to the specific file from which the log record was obtained appears in the output log entry as the value of the agent.googleapis.com/log_file_path label. When using a wildcard, only the path of the file from which the record was obtained is recorded.
type This value must be cassandra_gc.
wildcard_refresh_interval 60s The interval at which wildcard file paths in include_paths are refreshed. Given as a time duration, for example 30s or 2m. This property might be useful under high logging throughputs where log files are rotated faster than the default interval.

What is logged

The logName is derived from the receiver IDs specified in the configuration. Detailed fields inside the LogEntry are as follows.

The cassandra_system logs contain the following fields in the LogEntry:

Field Type Description
jsonPayload.javaClass string Java class where the log originated
jsonPayload.level string Log entry level
jsonPayload.lineNumber string Line number of the source file where the log originated
jsonPayload.message string Log message, including detailed stacktrace where provided
jsonPayload.module string Module of cassandra where the log originated
severity string (LogSeverity) Log entry level (translated).

The cassandra_debug logs contain the following fields in the LogEntry:

Field Type Description
jsonPayload.javaClass string Java class where the log originated
jsonPayload.level string Log entry level
jsonPayload.lineNumber string Line number of the source file where the log originated
jsonPayload.message string Log message
jsonPayload.module string Module of cassandra where the log originated
severity string (LogSeverity) Log entry level (translated).

The cassandra_gc logs contain the following fields in the LogEntry:

Field Type Description
jsonPayload.level string Level of the log entry
jsonPayload.message string Log message
jsonPayload.pid string Process ID of the Java process logging the message
jsonPayload.tid string Thread ID of the Java process logging the message
jsonPayload.timeStopped string Seconds the JVM was stopped for garbage collection
jsonPayload.timeStopping string Seconds the JVM took to stop threads before garbage collection
jsonPayload.uptime string Seconds the JVM has been active
severity string (LogSeverity) Log entry level (translated).

Configure metrics collection

To ingest metrics from Cassandra, you must create a receiver for the metrics that Cassandra produces and then create a pipeline for the new receiver.

This receiver does not support the use of multiple instances in the configuration, for example, to monitor multiple endpoints. All such instances write to the same time series, and Cloud Monitoring has no way to distinguish among them.

To configure a receiver for your cassandra metrics, specify the following fields:

Field Default Description
collect_jvm_metrics true Configures the receiver to also collect the supported JVM metrics.
collection_interval 60s A time duration value, such as 30s or 5m.
endpoint localhost:7199 The JMX Service URL or host and port used to construct the service URL. This value must be in the form of service:jmx:<protocol>:<sap> or host:port. Values in host:port form are used to create a service URL of service:jmx:rmi:///jndi/rmi://<host>:<port>/jmxrmi.
password The configured password if JMX is configured to require authentication.
type This value must be cassandra.
username The configured username if JMX is configured to require authentication.

What is monitored

The following table provides the list of metrics that the Ops Agent collects from the Cassandra instance.

Metric type 
Kind, Type
Monitored resources		 Labels
workload.googleapis.com/cassandra.client.request.count
CUMULATIVE, INT64
gce_instance 		operation
workload.googleapis.com/cassandra.client.request.error.count
CUMULATIVE, INT64
gce_instance 		operation
status
workload.googleapis.com/cassandra.client.request.range_slice.latency.50p
GAUGE, DOUBLE
gce_instance 		 
workload.googleapis.com/cassandra.client.request.range_slice.latency.99p
GAUGE, DOUBLE
gce_instance 		 
workload.googleapis.com/cassandra.client.request.range_slice.latency.max
GAUGE, DOUBLE
gce_instance 		 
workload.googleapis.com/cassandra.client.request.read.latency.50p
GAUGE, DOUBLE
gce_instance 		 
workload.googleapis.com/cassandra.client.request.read.latency.99p
GAUGE, DOUBLE
gce_instance 		 
workload.googleapis.com/cassandra.client.request.read.latency.max
GAUGE, DOUBLE
gce_instance 		 
workload.googleapis.com/cassandra.client.request.write.latency.50p
GAUGE, DOUBLE
gce_instance 		 
workload.googleapis.com/cassandra.client.request.write.latency.99p
GAUGE, DOUBLE
gce_instance 		 
workload.googleapis.com/cassandra.client.request.write.latency.max
GAUGE, DOUBLE
gce_instance 		 
workload.googleapis.com/cassandra.compaction.tasks.completed
CUMULATIVE, INT64
gce_instance 		 
workload.googleapis.com/cassandra.compaction.tasks.pending
GAUGE, INT64
gce_instance 		 
workload.googleapis.com/cassandra.storage.load.count
GAUGE, INT64
gce_instance 		 
workload.googleapis.com/cassandra.storage.total_hints.count
CUMULATIVE, INT64
gce_instance 		 
workload.googleapis.com/cassandra.storage.total_hints.in_progress.count
GAUGE, INT64
gce_instance 		 

Verify the configuration

This section describes how to verify that you correctly configured the Cassandra receiver. It might take one or two minutes for the Ops Agent to begin collecting telemetry.

To verify that Cassandra logs are being sent to Cloud Logging, do the following:

  1. In the Google Cloud console, go to the Logs Explorer page:

    Go to Logs Explorer

    If you use the search bar to find this page, then select the result whose subheading is Logging.

  2. Enter the following query in the editor, and then click Run query: 
    resource.type="gce_instance"
(log_id("cassandra_system") OR log_id("cassandra_debug") OR log_id("cassandra_gc"))

To verify that Cassandra metrics are being sent to Cloud Monitoring, do the following:

  1. In the Google Cloud console, go to the  Metrics explorer page:

    Go to Metrics explorer

    If you use the search bar to find this page, then select the result whose subheading is Monitoring.

  2. In the toolbar of the query-builder pane, select the button whose name is either  MQL or  PromQL.
  3. Verify that MQL is selected in the Language toggle. The language toggle is in the same toolbar that lets you format your query.
  4. Enter the following query in the editor, and then click Run query: 
    fetch gce_instance
| metric 'workload.googleapis.com/cassandra.client.request.count'
| every 1m

View dashboard

To view your Cassandra metrics, you must have a chart or dashboard configured. The Cassandra integration includes one or more dashboards for you. Any dashboards are automatically installed after you configure the integration and the Ops Agent has begun collecting metric data.

You can also view static previews of dashboards without installing the integration.

To view an installed dashboard, do the following:

  1. In the Google Cloud console, go to the  Dashboards page:

    Go to Dashboards

    If you use the search bar to find this page, then select the result whose subheading is Monitoring.

  2. Select the Dashboard List tab, and then choose the Integrations category.
  3. Click the name of the dashboard you want to view.

If you have configured an integration but the dashboard has not been installed, then check that the Ops Agent is running. When there is no metric data for a chart in the dashboard, installation of the dashboard fails. After the Ops Agent begins collecting metrics, the dashboard is installed for you.

To view a static preview of the dashboard, do the following:

  1. In the Google Cloud console, go to the  Integrations page:

    Go to Integrations

    If you use the search bar to find this page, then select the result whose subheading is Monitoring.

  2. Click the Compute Engine deployment-platform filter.
  3. Locate the entry for Cassandra and click View Details.
  4. Select the Dashboards tab to see a static preview. If the dashboard is installed, then you can navigate to it by clicking View dashboard.

For more information about dashboards in Cloud Monitoring, see Dashboards and charts.

For more information about using the Integrations page, see Manage integrations.

Install alerting policies

Alerting policies instruct Cloud Monitoring to notify you when specified conditions occur. The Cassandra integration includes one or more alerting policies for you to use. You can view and install these alerting policies from the Integrations page in Monitoring.

To view the descriptions of available alerting policies and install them, do the following:

  1. In the Google Cloud console, go to the  Integrations page:

    Go to Integrations

    If you use the search bar to find this page, then select the result whose subheading is Monitoring.

  2. Locate the entry for Cassandra and click View Details.
  3. Select the Alerts tab. This tab provides descriptions of available alerting policies and provides an interface for installing them.
  4. Install alerting policies. Alerting policies need to know where to send notifications that the alert has been triggered, so they require information from you for installation. To install alerting policies, do the following:
    1. From the list of available alerting policies, select those that you want to install.

    2. In the Configure notifications section, select one or more notification channels. You have the option to disable the use of notification channels, but if you do, then your alerting policies fire silently. You can check their status in Monitoring, but you receive no notifications.

      For more information about notification channels, see Manage notification channels.

    3. Click Create Policies.

For more information about alerting policies in Cloud Monitoring, see Introduction to alerting.

For more information about using the Integrations page, see Manage integrations.

What's next

For a walkthrough on how to use Ansible to install the Ops Agent, configure a third-party application, and install a sample dashboard, see the Install the Ops Agent to troubleshoot third-party applications video.