Cloudera Docs

Creating triggers and monitoring replication-related metrics in Cloudera Manager

After you create an HBase replication policy between two Cloudera Operational Database (COD) clusters in Cloudera Replication Manager, you can set up the triggers in Cloudera Manager to monitor specific replication-related metrics for the HBase replication policy. When the condition specified in the trigger is met, Cloudera Manager triggers an alert, and you can view the metrics for the replication policy in Cloudera Replication Manager and in Cloudera Manager.

  1. Go to the source Cloudera Manager > Hosts > All Hosts page.
  2. Click a link in the Name column to open the host status page.
  3. Click Create Trigger in the Health Tests section.
    For information about creating a trigger, see Cloudera Manager Trigger Use Cases. For information about the list of supported HBase RegionServer replication peer metrics, see HBase RegionServer Replication Peer Metrics.
  4. Enter the required values and the following expression to create a trigger for a metric with a certain threshold value on the Create New Trigger page:
    IF (SELECT [***ENTER THE METRIC NAME***] WHERE serviceName=$SERVICENAME AND max([***ENTER THE METRIC NAME***]) > [***ENTER THE THRESHOLD VALUE***] AND roleType=RegionServer) DO health:concerning
    The following examples illustrate how you can use triggers to monitor the replication metrics in Cloudera Manager:
    1. The IF (SELECT log_queue_size WHERE serviceName=$SERVICENAME AND max(log_queue_size) > 10 AND roleType=RegionServer) DO health:concerning trigger statement triggers the health alert when the value of the log_queue_size is greater than 2.
      This trigger condition is met when the processing of the queue becomes slow which results in the logs being queued or the replication process being halted.
    2. The following sample image shows the chart that appears on the source Cloudera Manager > Charts page when the health alert is triggered for the following trigger expression: IF (SELECT shipped_batches_rate WHERE serviceName=$SERVICENAME AND max(shipped_batches_rate) > 0.01 AND roleType=RegionServer) DO health:concerning
      The image shows the chart that appears on the Charts page in source Cloudera Manager when the health alert is triggered for the a trigger expression.
    3. The following image shows the Chart Builder where you can configure the options as required and save it for troubleshooting purposes or for future references.
      The image shows the chart builder in Cloudera Manager where you can configure the options as required for the charts you want to view and save.

      For information about monitoring the metrics related to replication and HBase health on your COD environment, see Monitor COD metrics.

You can view and monitor the metrics in Cloudera Manager and on the Charts page in Cloudera Replication Manager.