Chapter 50. Control Center
PPEM supports the control center that you can use for monitoring the state of clusters and instances, as well as troubleshooting them if required.
To view the state of clusters or instances using control center:
In the navigation panel, go to Monitoring → Operation control center.
Depending on what you want to view, switch to the Clusters or Instances tab.
The control center page will be displayed. It contains cluster or instance tiles at the top, and the metrics graph at the bottom. The graph is not shown if no cluster or instance tile is selected.
Using Tiles #
Clusters and instances are displayed as tiles.
Each tile displays the following information:
For a cluster:
Name.
The cluster type: regular, BiHA, or Patroni.
Total number of nodes in the cluster.
The number of healthy nodes in the cluster.
The minimum number of healthy nodes in the cluster for it to be considered healthy.
For an instance:
Uptime.
Name of the instance.
Name of the server where the instance is located.
The color of a tile allows you to quickly determine the health status of the related cluster or instance:
: healthy, normal operation
: warning, pay attention
: unhealthy, disrupted operation
: unknown
You can perform the following actions using tiles:
To view the detailed information, hover over a tile.
To view the metrics graph, click a tile.
To go to the page of a cluster or instance, click → Go to cluster or Go to instance, respectively.
To open the psql terminal for a cluster or instance, click → Open PSQL terminal or Open PSQL-console, respectively.
For a cluster, the name of the leader/primary node to be connected to is displayed.
To switch over a cluster to a new leader/primary node, click → Switch over to a new leader or Switch over to a new primary node, respectively.
To start a stopped instance, click → Start instance.
Using the Metrics Graph #
The metrics graph is based on metrics collected by pgpro-otel-collector and allows monitoring key instance performance indicators.
For the graph to work properly, you must first install and configure logging and monitoring tools.
To display the metrics graph for a cluster or instance, click the related tile. Optionally, select another graph from the drop-down list in top-right corner of a graph.
The following metrics graphs are available:
For a cluster:
Streaming Replication: Lag, bytes: The data lag between the primary/leader and the standby/follower node, in bytes.
Streaming Replication: Lag, time: The time lag between the primary/leader and the standby/follower node, in seconds.
For an instance:
Instance: Connections: Connections established with the DBMS instance and their state.
Instance: Blocks rate: The number of cache hits and misses that resulted in the need to read data from disk.
Instance: Transactions rate: Transactional activity in the DBMS instance.
Instance: Events: Deadlocks, replication conflicts, and checksum validation errors in the DBMS instance.
Instance: Tuples: The number of rows read, inserted, updated, and deleted.
Instance: Cache hit ratio: The proportion of cache hits relative to all shared cache accesses.
Instance: Temp Bytes Written: The amount of data written to temporary files.
Instance: Temp Files: The number of temporary files written by the DBMS instance.
Instance: Locks: Lock dynamics.
Instance: Wait Events Types: The count of wait events, grouped by type.
The
ClientReadandExtensionwait events, as well as the wait events ofActivityandTimeouttypes, are not displayed in this graph.Instance: Wait Events: The count of wait events.
The
ClientReadandExtensionwait events, as well as the wait events ofActivityandTimeouttypes, are not displayed in this graph.
You can perform the following actions using the graph:
Select a different metrics graph from the drop-down list in the top-right corner of the graph.
Select or specify a time period of interest by performing one of the following actions:
In the top-right corner of the graph, specify a time period or select it from the drop-down list.
In the top-right corner of the graph, click . Then, inside the graph, press the left mouse button and drag the cursor to select a horizontal area that represents a time period of interest.
The graph is scaled in accordance with the selected time interval. To reset the graph scale factor to the one listed in the drop-down list, in the top-right corner of the graph, click .
Download the graph in the PNG or CSV format by clicking or , respectively, in the top-right corner of the graph.