The Streaming Replication Analysis Dashboard

The Streaming Replication Analysis Dashboard displays statistical information about WAL activity for a monitored server. By default, replication probes are disabled; to view the Streaming Replication Analysis dashboard, you must enable probes on the master and standby nodes. To enable the probes on the master node, highlight the name of the master server in the PEM client Browser tree control, and select Manage Probes… from the Management menu. Use the Manage Probes tab to enable the following probes:

  • Streaming Replication
  • WAL Archive Status

To enable the probes on the standby node, highlight the name of the standby server in the PEM client Browser tree control, and select Manage Probes… from the Management menu. Use the Manage Probes tab to enable the following probe:

  • Streaming Replication Lag Time

Then, to open the Streaming Replication Analysis dashboard, navigate to the Monitoring tab, and:

  1. Select the name of the agent that monitors the node from the Agents drop-down menu.
  2. Select the name of the monitored server from the Servers drop-down menu.
  3. Select Streaming Replication Analysis from the Dashboards drop-down menu.

The Streaming Replication Analysis dashboard header includes the date and time that the server was last started, the date and time that the page was last updated, and a current count of triggered alerts.

When accessing the Streaming Replication Analysis dashboard for the master node of a replication scenario, the dashboard displays information about the write-ahead log activity for the server.

Streaming replication analysis dashboard for master

The WAL Archive Status graph displays WAL activity; the vertical key on the left side of the graph indicates the archive count; times are displayed across the bottom of the graph.

The WAL Segment Lag graph displays the segment lag for the standby nodes that are associated with the selected server. The vertical key on the left side of the graph indicates the archive count. Each node is displayed in a different color on the graph. The Legend provides a key to the identity (hostname and port) of each graphed standby node.

The WAL Page Lag graph displays the page lag activity for each standby node associated with the selected server. The vertical key on the left side of the graph indicates the page count. Each node is displayed in a different color on the graph. The Legend provides a key to the identity (hostname and port) of each graphed standby node.

Monitoring a Standby Node

When accessing the Streaming Replication Analysis dashboard for the standby node of a replication scenario, the dashboard displays information about the write-ahead log activity for the server.

Streaming replication analysis dashboard for standby

The WAL Archive Status graph displays WAL activity; the vertical key on the left side of the graph indicates the archive count; times are displayed across the bottom of the graph.

The WAL Segment Lag graph displays the segment lag for the standby nodes that are associated with the selected server. The vertical key on the left side of the graph indicates the archive count. Each standby node is displayed in a different color on the graph. The Legend provides a key to the identity (hostname and port) of each graphed slave node.

The WAL Page Lag graph displays the page lag activity for each standby node associated with the selected server. The vertical key on the left side of the graph indicates the page count. Each node is displayed in a different color on the graph. The Legend provides a key to the identity (hostname and port) of each graphed slave node.

The Replication Time Lag graph displays the delay between the time that an operation is performed on the master node of the replication scenario and the time that the operation is written to the standby node. The vertical key on the left side of the graph indicates the replication delay in minutes. Hover your mouse over a point on the graph to display the date and time that corresponds to that coordinate.

A label at the bottom of the dashboard confirms the status of the replication standby.

Monitoring a Failover Manager Cluster

If you have configured PEM to monitor a Failover Manager cluster, the Streaming Replication Analysis dashboard will display tables that provide an overview of the clusters status and configuration, and information about each cluster member. To display cluster information on the Streaming Replication dashboard, you must provide the following information on the Advanced tab of the server Properties dialog for each node of the cluster:

  • Use the EFM Cluster Name field to specify the name of the Failover Manager cluster. The cluster name is the prefix of the name of the cluster properties file. For example, if your cluster properties file is named efm.properties, your cluster name is efm.
  • Use the EFM Installation Path field to specify the location of the Failover Manager binary file. By default, the Failover Manager binary file is installed in /usr/edb/efm-3.1/bin.

The Failover Manager Cluster Status section of the Streaming Replication Analysis dashboard displays information about the monitored cluster:

Failover manager cluster status

The Failover Manager Cluster Information table provides information about the Failover Manager cluster:

  • The Properties column displays the name of the cluster property.
  • The Values column displays the current value of the property.

The Failover Manager Node Status table displays information about each node of the Failover Manager cluster:

  • The Agent Type column displays the type of agent that resides on the node; the possible values are Master, Standby, Witness, Idle, and Promoting.
  • The Address column displays the IP address of the node.
  • The Agent column displays the status of the agent that resides on the node.
  • The DB column displays the status of the database that resides on the node.
  • The XLog Location column displays the transaction log location of the database.
  • The Status Information column displays any error-related information about the node.
  • The XLog Information column displays any error-related information about the transaction log.
  • The VIP column displays the VIP address that is associated with the node.
  • The VIP Status column displays True if the VIP is active for the node, False if the VIP is not.