Monitoring the state of PostgreSQL clusters and hosts
Data on cluster and host states are available in the management console. You can view them on the Monitoring tab of the cluster management page.
Diagnostic information about cluster states is presented as graphs.
Chart update rate:
- Standard hosts and hosts with an increased RAM to vCPU ratio (
memory-optimized
): 15 seconds. - Hosts with a guaranteed vCPU share under 100% (
burstable
): 150 seconds.
Note
The most appropriate multiple units (MB, GB, and more) are automatically used in charts.
Monitoring cluster status
To view detailed information about the Managed Service for PostgreSQL cluster status:
-
Go to the folder page and select Managed Service for PostgreSQL.
-
Click on the name of the cluster and open the Monitoring tab.
The following charts open on the page:
- Age of oldest transaction/statement: Oldest transaction processing and operator execution time.
- Average transaction/statement time: Average transaction processing and operator execution time.
- CPU usage: Usage of processor cores.
- Disk read/write bytes: Disk read and write speed (bytes per second).
- Disk read/write IOPS: Disk read and write activity (ops per second).
- Disk usage by DB: Disk usage by database (bytes).
- Disk usage on primary: Disk usage on a master host (bytes).
- Is Primary, [boolean]: Indicates which host is the master and for how long.
- Log errors: Number of logged errors per second.
- Network received/sent bytes: Network data transfer speed (bytes per second).
- Packets received/sent: Network packet transmission activity (packets per second).
- Pooler is alive, [boolean]: Pooler health for each host either as a master or as a replica.
- PostgreSQL Alive, [boolean]: PostgreSQL health for each host either as a master or as a replica.
- Replication lag: Replication delay.
- Session CPU usage cores: Number of utilized processor cores by session type.
- Sessions per wait event: Number of waiting sessions by wait type.
- Sessions read bytes: Amount of data read by session type (bytes).
- Sessions write bytes: Amount of data written by session type (bytes).
- Statement quantiles: Operator execution time by percentile.
- TCP connections: Number of TCP connections per second.
- Total pooler connections: Number of pooler connections, both client and server.
- Total size of temporary files: Total temporary file size (bytes).
- Total size of WAL files: Total WAL file size (bytes).
- Transaction quantiles: Transaction processing time by percentile.
- Transactions/statements per second: Number of transactions and operators per second.
Monitoring the state of hosts
To view detailed information about the status of individual Managed Service for PostgreSQL hosts:
- Go to the folder page and select Managed Service for PostgreSQL.
- Click the name of the desired cluster and select Hosts → Monitoring.
- Select the host from the drop-down list.
This page displays charts showing the load on an individual host in the cluster:
- CPU usage: Usage of processor cores. As the load goes up, the Idle value goes down.
- Disk IOPS: Number of disk operations per second.
- Disk read/write bytes: Speed of disk operations, in bytes per second.
- Memory usage: Use of RAM, in bytes. At high loads, the value of the Free parameter goes down while those of other parameters go up.
- Network bytes: Speed of data exchange over the network, in bytes per second.
- Network packets: Number of packets exchanged over the network, per second.
The Disk read/write bytes and the Disk IOPS charts show that the Read property increases when active database reads are in progress, and that Write increases when database writes are in progress.
For hosts with the Replica role, it's normal that Received is greater than Sent on the Network Bytes and Network Packets charts.
Cluster state and status
The State of a cluster shows the health of its hosts, while the Status shows whether the cluster is started, stopped, or is at an intermediate stage.
To view a cluster's state and status:
- Go to the folder page and select Managed Service for PostgreSQL.
- Hover over the indicator in the Availability column in the row of the cluster you need.
Cluster states
Status | Description | Suggested actions |
---|---|---|
ALIVE | Cluster is operating normally. | No action is required. |
DEGRADED | Cluster is not running at its full capacity: the state of at least one of the hosts is other than ALIVE . |
Run the diagnostics:
|
DEAD | Cluster is out of order: all of its hosts are down. | Send a request to the support team
|
UNKNOWN | Cluster state is unknown. | Send a request to the support team
|
Cluster statuses
Status | Description | Suggested actions |
---|---|---|
CREATING | Preparing for the first launch | Wait a while and get started. The time it takes to create a cluster depends on the host class. |
RUNNING | Cluster is operating normally | No action is required. |
STOPPING | Stopping cluster | After a while, the cluster's status will change to STOPPED and it will be disabled. No action is required. |
STOPPED | Cluster stopped | For instructions on how to restart it, see Stopping and restarting a cluster. |
STARTING | Starting the cluster that was stopped earlier | After a while, the cluster's status will change to RUNNING . Wait a while and get started. |
UPDATING | Updating the cluster status | After the update is completed, the cluster's status will change to RUNNING . Wait a while and get started. |
ERROR | An error occurred that doesn't allow the cluster to continue working | Run the initial diagnostics:
|
STATUS_UNKNOWN | Cluster is unable to determine its own status | Run the initial diagnostics:
|