Chapter 3. Configure LokiStack resource limits

Procedure

1. In the OpenShift Container Platform web console, navigate to Observe Metrics.
2. Set the time range to 1w (1 week) to view historical usage patterns.

3. Query CPU usage for all LokiStack components:

   Note

   These queries assume that your LokiStack custom resource is named logging-loki. If you used a different name, replace logging-loki.* with <your-lokistack-name>.* in the queries.

   pod:container_cpu_usage:sum{pod=~"logging-loki.*",namespace="openshift-logging"}

   Review the peak CPU usage for each component over the past week.

4. Query memory usage for all LokiStack components:

   sum(container_memory_working_set_bytes{pod=~"logging-loki.*",namespace="openshift-logging",container=""}) BY (pod, namespace)

   Review the peak memory usage for each component over the past week.

5. Compare the peak usage values (not current values) against the resource requests for your LokiStack size in the sizing tables:

   • For CPU: Peak usage should be below the CPU request per pod for each component.
   • For memory: Peak memory (in bytes) should be below the memory request per pod for each component.

   For per-component resource tables for your size, see the additional resources at the end of this topic.

   If the current usage of any component exceeds its resource request, do not enable useRequestsAsLimits until you complete one of the following actions:

   • Increase the LokiStack size to one with higher resource allocations.
   • Reduce log ingestion volume to decrease resource consumption.
   • Investigate why components are consuming more resources than expected.

Procedure

1. Set resource limits equal to requests for all LokiStack components by setting spec.template.useRequestsAsLimits to true:

   apiVersion: loki.grafana.com/v1
   kind: LokiStack
   metadata:
     name: logging-loki
     namespace: openshift-logging
   spec:
     size: 1x.small
     template:
       useRequestsAsLimits: true

   spec.template.useRequestsAsLimits

   Sets resource limits equal to resource requests for all LokiStack components (distributor, ingester, querier, query front-end, compactor, index-gateway, ruler, and gateway). This setting applies to all components. You cannot set limits for individual components.

Procedure

1. Check a LokiStack pod’s resource configuration:

   $ oc get pod -n openshift-logging -l app.kubernetes.io/component=ingester -o jsonpath='{.items[0].spec.containers[0].resources}' | jq

   Example output

   {
     "limits": {
       "cpu": "1",
       "memory": "2Gi"
     },
     "requests": {
       "cpu": "1",
       "memory": "2Gi"
     }
   }

2. Verify that the values for requests and limits are the same for both CPU and memory.