Chapter 8. Virtual database monitoring
Prometheus is an open-source systems and service monitoring and alerting toolkit that you can use to monitor services deployed in your Red Hat OpenShift environment. Prometheus collects and stores metrics from configured services at given intervals, evaluates rule expressions, displays the results, and can trigger alerts if a specified condition becomes true.
Red Hat support for Prometheus is limited to the setup and configuration recommendations provided in Red Hat product documentation.
Prometheus communicates with the data virtualization service to retrieve metrics and data. Users can query the data, or use a visualization took such as Grafana to view trends in a dashboard.
To enable monitoring of an OpenShift service, the service must expose an endpoint to Prometheus. This endpoint is an HTTP interface that provides a list of metrics and the current values of the metrics. When you use the Data Virtualization Operator to create a virtual database, the data virtualization service automatically exposes an HTTP endpoint to Prometheus. Prometheus periodically scrapes each target-defined endpoint and writes the collected data to its database.
After Prometheus is deployed to an OpenShift cluster, the metrics for any virtualization that you deploy to the same cluster are exposed to the Prometheus service automatically.
The following tables list the runtime and cache metrics that the data virtualization service exposes to Prometheus:
| Name | Description | Type |
|---|---|---|
| org.teiid.TotalRequestsProcessed | Total requests processed | Counter |
| org.teiid.WaitingRequestsCount | Requests queued for processing | Gauge |
| org.teiid.ActiveEngineThreadCount | Number of current engine threads | Gauge |
| org.teiid.QueuedEngineWorkItems | Number of queued work items | Gauge |
| org.teiid.LongRunningRequestCount | Number of long-running requests | Gauge |
| org.teiid.TotalOutOfDiskErrors | Total buffer out-of-disk errors | Counter |
| org.teiid.PercentBufferDiskSpaceInUse | Percent buffer disk space in use | Gauge |
| org.teiid.SessionCount | Number of client sessions | Gauge |
| org.teiid.DiskSpaceUsedInMB | Disk space used (MB) | Gauge |
| org.teiid.ActiveRequestCount | Active requests | Gauge |
| Name | Description | Type |
|---|---|---|
| org.teiid.CacheRequestCount | Number of cache reads | Gauge |
| org.teiid.CacheTotalEntries | Number of cache entries | Gauge |
| org.teiid.CacheHitRatio | Ratio of cache hits to total attempts | Gauge |
For more information about deploying Prometheus to monitor services on OpenShift, see the OpenShift documentation.
