Chapter 4. Troubleshooting logging
4.1. Viewing Logging status
You can view the status of the Red Hat OpenShift Logging Operator and other logging components.
4.1.1. Viewing the status of the Red Hat OpenShift Logging Operator
You can view the status of the Red Hat OpenShift Logging Operator.
Prerequisites
- The Red Hat OpenShift Logging Operator and OpenShift Elasticsearch Operator are installed.
Procedure
Change to the
openshift-logging
project by running the following command:$ oc project openshift-logging
Get the
ClusterLogging
instance status by running the following command:$ oc get clusterlogging instance -o yaml
Example output
apiVersion: logging.openshift.io/v1 kind: ClusterLogging # ... status: 1 collection: logs: fluentdStatus: daemonSet: fluentd 2 nodes: collector-2rhqp: ip-10-0-169-13.ec2.internal collector-6fgjh: ip-10-0-165-244.ec2.internal collector-6l2ff: ip-10-0-128-218.ec2.internal collector-54nx5: ip-10-0-139-30.ec2.internal collector-flpnn: ip-10-0-147-228.ec2.internal collector-n2frh: ip-10-0-157-45.ec2.internal pods: failed: [] notReady: [] ready: - collector-2rhqp - collector-54nx5 - collector-6fgjh - collector-6l2ff - collector-flpnn - collector-n2frh logstore: 3 elasticsearchStatus: - ShardAllocationEnabled: all cluster: activePrimaryShards: 5 activeShards: 5 initializingShards: 0 numDataNodes: 1 numNodes: 1 pendingTasks: 0 relocatingShards: 0 status: green unassignedShards: 0 clusterName: elasticsearch nodeConditions: elasticsearch-cdm-mkkdys93-1: nodeCount: 1 pods: client: failed: notReady: ready: - elasticsearch-cdm-mkkdys93-1-7f7c6-mjm7c data: failed: notReady: ready: - elasticsearch-cdm-mkkdys93-1-7f7c6-mjm7c master: failed: notReady: ready: - elasticsearch-cdm-mkkdys93-1-7f7c6-mjm7c visualization: 4 kibanaStatus: - deployment: kibana pods: failed: [] notReady: [] ready: - kibana-7fb4fd4cc9-f2nls replicaSets: - kibana-7fb4fd4cc9 replicas: 1
4.1.1.1. Example condition messages
The following are examples of some condition messages from the Status.Nodes
section of the ClusterLogging
instance.
A status message similar to the following indicates a node has exceeded the configured low watermark and no shard will be allocated to this node:
Example output
nodes: - conditions: - lastTransitionTime: 2019-03-15T15:57:22Z message: Disk storage usage for node is 27.5gb (36.74%). Shards will be not be allocated on this node. reason: Disk Watermark Low status: "True" type: NodeStorage deploymentName: example-elasticsearch-clientdatamaster-0-1 upgradeStatus: {}
A status message similar to the following indicates a node has exceeded the configured high watermark and shards will be relocated to other nodes:
Example output
nodes: - conditions: - lastTransitionTime: 2019-03-15T16:04:45Z message: Disk storage usage for node is 27.5gb (36.74%). Shards will be relocated from this node. reason: Disk Watermark High status: "True" type: NodeStorage deploymentName: cluster-logging-operator upgradeStatus: {}
A status message similar to the following indicates the Elasticsearch node selector in the CR does not match any nodes in the cluster:
Example output
Elasticsearch Status: Shard Allocation Enabled: shard allocation unknown Cluster: Active Primary Shards: 0 Active Shards: 0 Initializing Shards: 0 Num Data Nodes: 0 Num Nodes: 0 Pending Tasks: 0 Relocating Shards: 0 Status: cluster health unknown Unassigned Shards: 0 Cluster Name: elasticsearch Node Conditions: elasticsearch-cdm-mkkdys93-1: Last Transition Time: 2019-06-26T03:37:32Z Message: 0/5 nodes are available: 5 node(s) didn't match node selector. Reason: Unschedulable Status: True Type: Unschedulable elasticsearch-cdm-mkkdys93-2: Node Count: 2 Pods: Client: Failed: Not Ready: elasticsearch-cdm-mkkdys93-1-75dd69dccd-f7f49 elasticsearch-cdm-mkkdys93-2-67c64f5f4c-n58vl Ready: Data: Failed: Not Ready: elasticsearch-cdm-mkkdys93-1-75dd69dccd-f7f49 elasticsearch-cdm-mkkdys93-2-67c64f5f4c-n58vl Ready: Master: Failed: Not Ready: elasticsearch-cdm-mkkdys93-1-75dd69dccd-f7f49 elasticsearch-cdm-mkkdys93-2-67c64f5f4c-n58vl Ready:
A status message similar to the following indicates that the requested PVC could not bind to PV:
Example output
Node Conditions: elasticsearch-cdm-mkkdys93-1: Last Transition Time: 2019-06-26T03:37:32Z Message: pod has unbound immediate PersistentVolumeClaims (repeated 5 times) Reason: Unschedulable Status: True Type: Unschedulable
A status message similar to the following indicates that the Fluentd pods cannot be scheduled because the node selector did not match any nodes:
Example output
Status: Collection: Logs: Fluentd Status: Daemon Set: fluentd Nodes: Pods: Failed: Not Ready: Ready:
4.1.2. Viewing the status of logging components
You can view the status for a number of logging components.
Prerequisites
- The Red Hat OpenShift Logging Operator and OpenShift Elasticsearch Operator are installed.
Procedure
Change to the
openshift-logging
project.$ oc project openshift-logging
View the status of logging environment:
$ oc describe deployment cluster-logging-operator
Example output
Name: cluster-logging-operator .... Conditions: Type Status Reason ---- ------ ------ Available True MinimumReplicasAvailable Progressing True NewReplicaSetAvailable .... Events: Type Reason Age From Message ---- ------ ---- ---- ------- Normal ScalingReplicaSet 62m deployment-controller Scaled up replica set cluster-logging-operator-574b8987df to 1----
View the status of the logging replica set:
Get the name of a replica set:
Example output
$ oc get replicaset
Example output
NAME DESIRED CURRENT READY AGE cluster-logging-operator-574b8987df 1 1 1 159m elasticsearch-cdm-uhr537yu-1-6869694fb 1 1 1 157m elasticsearch-cdm-uhr537yu-2-857b6d676f 1 1 1 156m elasticsearch-cdm-uhr537yu-3-5b6fdd8cfd 1 1 1 155m kibana-5bd5544f87 1 1 1 157m
Get the status of the replica set:
$ oc describe replicaset cluster-logging-operator-574b8987df
Example output
Name: cluster-logging-operator-574b8987df .... Replicas: 1 current / 1 desired Pods Status: 1 Running / 0 Waiting / 0 Succeeded / 0 Failed .... Events: Type Reason Age From Message ---- ------ ---- ---- ------- Normal SuccessfulCreate 66m replicaset-controller Created pod: cluster-logging-operator-574b8987df-qjhqv----
4.2. Troubleshooting log forwarding
4.2.1. Redeploying Fluentd pods
When you create a ClusterLogForwarder
custom resource (CR), if the Red Hat OpenShift Logging Operator does not redeploy the Fluentd pods automatically, you can delete the Fluentd pods to force them to redeploy.
Prerequisites
-
You have created a
ClusterLogForwarder
custom resource (CR) object.
Procedure
Delete the Fluentd pods to force them to redeploy by running the following command:
$ oc delete pod --selector logging-infra=collector
4.2.2. Troubleshooting Loki rate limit errors
If the Log Forwarder API forwards a large block of messages that exceeds the rate limit to Loki, Loki generates rate limit (429
) errors.
These errors can occur during normal operation. For example, when adding the logging to a cluster that already has some logs, rate limit errors might occur while the logging tries to ingest all of the existing log entries. In this case, if the rate of addition of new logs is less than the total rate limit, the historical data is eventually ingested, and the rate limit errors are resolved without requiring user intervention.
In cases where the rate limit errors continue to occur, you can fix the issue by modifying the LokiStack
custom resource (CR).
The LokiStack
CR is not available on Grafana-hosted Loki. This topic does not apply to Grafana-hosted Loki servers.
Conditions
- The Log Forwarder API is configured to forward logs to Loki.
Your system sends a block of messages that is larger than 2 MB to Loki. For example:
"values":[["1630410392689800468","{\"kind\":\"Event\",\"apiVersion\":\ ....... ...... ...... ...... \"received_at\":\"2021-08-31T11:46:32.800278+00:00\",\"version\":\"1.7.4 1.6.0\"}},\"@timestamp\":\"2021-08-31T11:46:32.799692+00:00\",\"viaq_index_name\":\"audit-write\",\"viaq_msg_id\":\"MzFjYjJkZjItNjY0MC00YWU4LWIwMTEtNGNmM2E5ZmViMGU4\",\"log_type\":\"audit\"}"]]}]}
After you enter
oc logs -n openshift-logging -l component=collector
, the collector logs in your cluster show a line containing one of the following error messages:429 Too Many Requests Ingestion rate limit exceeded
Example Vector error message
2023-08-25T16:08:49.301780Z WARN sink{component_kind="sink" component_id=default_loki_infra component_type=loki component_name=default_loki_infra}: vector::sinks::util::retries: Retrying after error. error=Server responded with an error: 429 Too Many Requests internal_log_rate_limit=true
Example Fluentd error message
2023-08-30 14:52:15 +0000 [warn]: [default_loki_infra] failed to flush the buffer. retry_times=2 next_retry_time=2023-08-30 14:52:19 +0000 chunk="604251225bf5378ed1567231a1c03b8b" error_class=Fluent::Plugin::LokiOutput::LogPostError error="429 Too Many Requests Ingestion rate limit exceeded for user infrastructure (limit: 4194304 bytes/sec) while attempting to ingest '4082' lines totaling '7820025' bytes, reduce log volume or contact your Loki administrator to see if the limit can be increased\n"
The error is also visible on the receiving end. For example, in the LokiStack ingester pod:
Example Loki ingester error message
level=warn ts=2023-08-30T14:57:34.155592243Z caller=grpc_logging.go:43 duration=1.434942ms method=/logproto.Pusher/Push err="rpc error: code = Code(429) desc = entry with timestamp 2023-08-30 14:57:32.012778399 +0000 UTC ignored, reason: 'Per stream rate limit exceeded (limit: 3MB/sec) while attempting to ingest for stream
Procedure
Update the
ingestionBurstSize
andingestionRate
fields in theLokiStack
CR:apiVersion: loki.grafana.com/v1 kind: LokiStack metadata: name: logging-loki namespace: openshift-logging spec: limits: global: ingestion: ingestionBurstSize: 16 1 ingestionRate: 8 2 # ...
- 1
- The
ingestionBurstSize
field defines the maximum local rate-limited sample size per distributor replica in MB. This value is a hard limit. Set this value to at least the maximum logs size expected in a single push request. Single requests that are larger than theingestionBurstSize
value are not permitted. - 2
- The
ingestionRate
field is a soft limit on the maximum amount of ingested samples per second in MB. Rate limit errors occur if the rate of logs exceeds the limit, but the collector retries sending the logs. As long as the total average is lower than the limit, the system recovers and errors are resolved without user intervention.
4.3. Troubleshooting logging alerts
You can use the following procedures to troubleshoot logging alerts on your cluster.
4.3.1. Elasticsearch cluster health status is red
At least one primary shard and its replicas are not allocated to a node. Use the following procedure to troubleshoot this alert.
Some commands in this documentation reference an Elasticsearch pod by using a $ES_POD_NAME
shell variable. If you want to copy and paste the commands directly from this documentation, you must set this variable to a value that is valid for your Elasticsearch cluster.
You can list the available Elasticsearch pods by running the following command:
$ oc -n openshift-logging get pods -l component=elasticsearch
Choose one of the pods listed and set the $ES_POD_NAME
variable, by running the following command:
$ export ES_POD_NAME=<elasticsearch_pod_name>
You can now use the $ES_POD_NAME
variable in commands.
Procedure
Check the Elasticsearch cluster health and verify that the cluster
status
is red by running the following command:$ oc exec -n openshift-logging -c elasticsearch $ES_POD_NAME -- health
List the nodes that have joined the cluster by running the following command:
$ oc exec -n openshift-logging -c elasticsearch $ES_POD_NAME \ -- es_util --query=_cat/nodes?v
List the Elasticsearch pods and compare them with the nodes in the command output from the previous step, by running the following command:
$ oc -n openshift-logging get pods -l component=elasticsearch
If some of the Elasticsearch nodes have not joined the cluster, perform the following steps.
Confirm that Elasticsearch has an elected master node by running the following command and observing the output:
$ oc exec -n openshift-logging -c elasticsearch $ES_POD_NAME \ -- es_util --query=_cat/master?v
Review the pod logs of the elected master node for issues by running the following command and observing the output:
$ oc logs <elasticsearch_master_pod_name> -c elasticsearch -n openshift-logging
Review the logs of nodes that have not joined the cluster for issues by running the following command and observing the output:
$ oc logs <elasticsearch_node_name> -c elasticsearch -n openshift-logging
If all the nodes have joined the cluster, check if the cluster is in the process of recovering by running the following command and observing the output:
$ oc exec -n openshift-logging -c elasticsearch $ES_POD_NAME \ -- es_util --query=_cat/recovery?active_only=true
If there is no command output, the recovery process might be delayed or stalled by pending tasks.
Check if there are pending tasks by running the following command and observing the output:
$ oc exec -n openshift-logging -c elasticsearch $ES_POD_NAME \ -- health | grep number_of_pending_tasks
- If there are pending tasks, monitor their status. If their status changes and indicates that the cluster is recovering, continue waiting. The recovery time varies according to the size of the cluster and other factors. Otherwise, if the status of the pending tasks does not change, this indicates that the recovery has stalled.
If it seems like the recovery has stalled, check if the
cluster.routing.allocation.enable
value is set tonone
, by running the following command and observing the output:$ oc exec -n openshift-logging -c elasticsearch $ES_POD_NAME \ -- es_util --query=_cluster/settings?pretty
If the
cluster.routing.allocation.enable
value is set tonone
, set it toall
, by running the following command:$ oc exec -n openshift-logging -c elasticsearch $ES_POD_NAME \ -- es_util --query=_cluster/settings?pretty \ -X PUT -d '{"persistent": {"cluster.routing.allocation.enable":"all"}}'
Check if any indices are still red by running the following command and observing the output:
$ oc exec -n openshift-logging -c elasticsearch $ES_POD_NAME \ -- es_util --query=_cat/indices?v
If any indices are still red, try to clear them by performing the following steps.
Clear the cache by running the following command:
$ oc exec -n openshift-logging -c elasticsearch $ES_POD_NAME \ -- es_util --query=<elasticsearch_index_name>/_cache/clear?pretty
Increase the max allocation retries by running the following command:
$ oc exec -n openshift-logging -c elasticsearch $ES_POD_NAME \ -- es_util --query=<elasticsearch_index_name>/_settings?pretty \ -X PUT -d '{"index.allocation.max_retries":10}'
Delete all the scroll items by running the following command:
$ oc exec -n openshift-logging -c elasticsearch $ES_POD_NAME \ -- es_util --query=_search/scroll/_all -X DELETE
Increase the timeout by running the following command:
$ oc exec -n openshift-logging -c elasticsearch $ES_POD_NAME \ -- es_util --query=<elasticsearch_index_name>/_settings?pretty \ -X PUT -d '{"index.unassigned.node_left.delayed_timeout":"10m"}'
If the preceding steps do not clear the red indices, delete the indices individually.
Identify the red index name by running the following command:
$ oc exec -n openshift-logging -c elasticsearch $ES_POD_NAME \ -- es_util --query=_cat/indices?v
Delete the red index by running the following command:
$ oc exec -n openshift-logging -c elasticsearch $ES_POD_NAME \ -- es_util --query=<elasticsearch_red_index_name> -X DELETE
If there are no red indices and the cluster status is red, check for a continuous heavy processing load on a data node.
Check if the Elasticsearch JVM Heap usage is high by running the following command:
$ oc exec -n openshift-logging -c elasticsearch $ES_POD_NAME \ -- es_util --query=_nodes/stats?pretty
In the command output, review the
node_name.jvm.mem.heap_used_percent
field to determine the JVM Heap usage.- Check for high CPU utilization. For more information about CPU utilitzation, see the OpenShift Container Platform "Reviewing monitoring dashboards" documentation.
Additional resources
4.3.2. Elasticsearch cluster health status is yellow
Replica shards for at least one primary shard are not allocated to nodes. Increase the node count by adjusting the nodeCount
value in the ClusterLogging
custom resource (CR).
Additional resources
4.3.3. Elasticsearch node disk low watermark reached
Elasticsearch does not allocate shards to nodes that reach the low watermark.
Some commands in this documentation reference an Elasticsearch pod by using a $ES_POD_NAME
shell variable. If you want to copy and paste the commands directly from this documentation, you must set this variable to a value that is valid for your Elasticsearch cluster.
You can list the available Elasticsearch pods by running the following command:
$ oc -n openshift-logging get pods -l component=elasticsearch
Choose one of the pods listed and set the $ES_POD_NAME
variable, by running the following command:
$ export ES_POD_NAME=<elasticsearch_pod_name>
You can now use the $ES_POD_NAME
variable in commands.
Procedure
Identify the node on which Elasticsearch is deployed by running the following command:
$ oc -n openshift-logging get po -o wide
Check if there are unassigned shards by running the following command:
$ oc exec -n openshift-logging -c elasticsearch $ES_POD_NAME \ -- es_util --query=_cluster/health?pretty | grep unassigned_shards
If there are unassigned shards, check the disk space on each node, by running the following command:
$ for pod in `oc -n openshift-logging get po -l component=elasticsearch -o jsonpath='{.items[*].metadata.name}'`; \ do echo $pod; oc -n openshift-logging exec -c elasticsearch $pod \ -- df -h /elasticsearch/persistent; done
In the command output, check the
Use
column to determine the used disk percentage on that node.Example output
elasticsearch-cdm-kcrsda6l-1-586cc95d4f-h8zq8 Filesystem Size Used Avail Use% Mounted on /dev/nvme1n1 19G 522M 19G 3% /elasticsearch/persistent elasticsearch-cdm-kcrsda6l-2-5b548fc7b-cwwk7 Filesystem Size Used Avail Use% Mounted on /dev/nvme2n1 19G 522M 19G 3% /elasticsearch/persistent elasticsearch-cdm-kcrsda6l-3-5dfc884d99-59tjw Filesystem Size Used Avail Use% Mounted on /dev/nvme3n1 19G 528M 19G 3% /elasticsearch/persistent
If the used disk percentage is above 85%, the node has exceeded the low watermark, and shards can no longer be allocated to this node.
To check the current
redundancyPolicy
, run the following command:$ oc -n openshift-logging get es elasticsearch \ -o jsonpath='{.spec.redundancyPolicy}'
If you are using a
ClusterLogging
resource on your cluster, run the following command:$ oc -n openshift-logging get cl \ -o jsonpath='{.items[*].spec.logStore.elasticsearch.redundancyPolicy}'
If the cluster
redundancyPolicy
value is higher than theSingleRedundancy
value, set it to theSingleRedundancy
value and save this change.If the preceding steps do not fix the issue, delete the old indices.
Check the status of all indices on Elasticsearch by running the following command:
$ oc exec -n openshift-logging -c elasticsearch $ES_POD_NAME -- indices
- Identify an old index that can be deleted.
Delete the index by running the following command:
$ oc exec -n openshift-logging -c elasticsearch $ES_POD_NAME \ -- es_util --query=<elasticsearch_index_name> -X DELETE
4.3.4. Elasticsearch node disk high watermark reached
Elasticsearch attempts to relocate shards away from a node that has reached the high watermark to a node with low disk usage that has not crossed any watermark threshold limits.
To allocate shards to a particular node, you must free up some space on that node. If increasing the disk space is not possible, try adding a new data node to the cluster, or decrease the total cluster redundancy policy.
Some commands in this documentation reference an Elasticsearch pod by using a $ES_POD_NAME
shell variable. If you want to copy and paste the commands directly from this documentation, you must set this variable to a value that is valid for your Elasticsearch cluster.
You can list the available Elasticsearch pods by running the following command:
$ oc -n openshift-logging get pods -l component=elasticsearch
Choose one of the pods listed and set the $ES_POD_NAME
variable, by running the following command:
$ export ES_POD_NAME=<elasticsearch_pod_name>
You can now use the $ES_POD_NAME
variable in commands.
Procedure
Identify the node on which Elasticsearch is deployed by running the following command:
$ oc -n openshift-logging get po -o wide
Check the disk space on each node:
$ for pod in `oc -n openshift-logging get po -l component=elasticsearch -o jsonpath='{.items[*].metadata.name}'`; \ do echo $pod; oc -n openshift-logging exec -c elasticsearch $pod \ -- df -h /elasticsearch/persistent; done
Check if the cluster is rebalancing:
$ oc exec -n openshift-logging -c elasticsearch $ES_POD_NAME \ -- es_util --query=_cluster/health?pretty | grep relocating_shards
If the command output shows relocating shards, the high watermark has been exceeded. The default value of the high watermark is 90%.
- Increase the disk space on all nodes. If increasing the disk space is not possible, try adding a new data node to the cluster, or decrease the total cluster redundancy policy.
To check the current
redundancyPolicy
, run the following command:$ oc -n openshift-logging get es elasticsearch \ -o jsonpath='{.spec.redundancyPolicy}'
If you are using a
ClusterLogging
resource on your cluster, run the following command:$ oc -n openshift-logging get cl \ -o jsonpath='{.items[*].spec.logStore.elasticsearch.redundancyPolicy}'
If the cluster
redundancyPolicy
value is higher than theSingleRedundancy
value, set it to theSingleRedundancy
value and save this change.If the preceding steps do not fix the issue, delete the old indices.
Check the status of all indices on Elasticsearch by running the following command:
$ oc exec -n openshift-logging -c elasticsearch $ES_POD_NAME -- indices
- Identify an old index that can be deleted.
Delete the index by running the following command:
$ oc exec -n openshift-logging -c elasticsearch $ES_POD_NAME \ -- es_util --query=<elasticsearch_index_name> -X DELETE
4.3.5. Elasticsearch node disk flood watermark reached
Elasticsearch enforces a read-only index block on every index that has both of these conditions:
- One or more shards are allocated to the node.
- One or more disks exceed the flood stage.
Use the following procedure to troubleshoot this alert.
Some commands in this documentation reference an Elasticsearch pod by using a $ES_POD_NAME
shell variable. If you want to copy and paste the commands directly from this documentation, you must set this variable to a value that is valid for your Elasticsearch cluster.
You can list the available Elasticsearch pods by running the following command:
$ oc -n openshift-logging get pods -l component=elasticsearch
Choose one of the pods listed and set the $ES_POD_NAME
variable, by running the following command:
$ export ES_POD_NAME=<elasticsearch_pod_name>
You can now use the $ES_POD_NAME
variable in commands.
Procedure
Get the disk space of the Elasticsearch node:
$ for pod in `oc -n openshift-logging get po -l component=elasticsearch -o jsonpath='{.items[*].metadata.name}'`; \ do echo $pod; oc -n openshift-logging exec -c elasticsearch $pod \ -- df -h /elasticsearch/persistent; done
In the command output, check the
Avail
column to determine the free disk space on that node.Example output
elasticsearch-cdm-kcrsda6l-1-586cc95d4f-h8zq8 Filesystem Size Used Avail Use% Mounted on /dev/nvme1n1 19G 522M 19G 3% /elasticsearch/persistent elasticsearch-cdm-kcrsda6l-2-5b548fc7b-cwwk7 Filesystem Size Used Avail Use% Mounted on /dev/nvme2n1 19G 522M 19G 3% /elasticsearch/persistent elasticsearch-cdm-kcrsda6l-3-5dfc884d99-59tjw Filesystem Size Used Avail Use% Mounted on /dev/nvme3n1 19G 528M 19G 3% /elasticsearch/persistent
- Increase the disk space on all nodes. If increasing the disk space is not possible, try adding a new data node to the cluster, or decrease the total cluster redundancy policy.
To check the current
redundancyPolicy
, run the following command:$ oc -n openshift-logging get es elasticsearch \ -o jsonpath='{.spec.redundancyPolicy}'
If you are using a
ClusterLogging
resource on your cluster, run the following command:$ oc -n openshift-logging get cl \ -o jsonpath='{.items[*].spec.logStore.elasticsearch.redundancyPolicy}'
If the cluster
redundancyPolicy
value is higher than theSingleRedundancy
value, set it to theSingleRedundancy
value and save this change.If the preceding steps do not fix the issue, delete the old indices.
Check the status of all indices on Elasticsearch by running the following command:
$ oc exec -n openshift-logging -c elasticsearch $ES_POD_NAME -- indices
- Identify an old index that can be deleted.
Delete the index by running the following command:
$ oc exec -n openshift-logging -c elasticsearch $ES_POD_NAME \ -- es_util --query=<elasticsearch_index_name> -X DELETE
Continue freeing up and monitoring the disk space. After the used disk space drops below 90%, unblock writing to this node by running the following command:
$ oc exec -n openshift-logging -c elasticsearch $ES_POD_NAME \ -- es_util --query=_all/_settings?pretty \ -X PUT -d '{"index.blocks.read_only_allow_delete": null}'
4.3.6. Elasticsearch JVM heap usage is high
The Elasticsearch node Java virtual machine (JVM) heap memory used is above 75%. Consider increasing the heap size.
4.3.7. Aggregated logging system CPU is high
System CPU usage on the node is high. Check the CPU of the cluster node. Consider allocating more CPU resources to the node.
4.3.8. Elasticsearch process CPU is high
Elasticsearch process CPU usage on the node is high. Check the CPU of the cluster node. Consider allocating more CPU resources to the node.
4.3.9. Elasticsearch disk space is running low
Elasticsearch is predicted to run out of disk space within the next 6 hours based on current disk usage. Use the following procedure to troubleshoot this alert.
Procedure
Get the disk space of the Elasticsearch node:
$ for pod in `oc -n openshift-logging get po -l component=elasticsearch -o jsonpath='{.items[*].metadata.name}'`; \ do echo $pod; oc -n openshift-logging exec -c elasticsearch $pod \ -- df -h /elasticsearch/persistent; done
In the command output, check the
Avail
column to determine the free disk space on that node.Example output
elasticsearch-cdm-kcrsda6l-1-586cc95d4f-h8zq8 Filesystem Size Used Avail Use% Mounted on /dev/nvme1n1 19G 522M 19G 3% /elasticsearch/persistent elasticsearch-cdm-kcrsda6l-2-5b548fc7b-cwwk7 Filesystem Size Used Avail Use% Mounted on /dev/nvme2n1 19G 522M 19G 3% /elasticsearch/persistent elasticsearch-cdm-kcrsda6l-3-5dfc884d99-59tjw Filesystem Size Used Avail Use% Mounted on /dev/nvme3n1 19G 528M 19G 3% /elasticsearch/persistent
- Increase the disk space on all nodes. If increasing the disk space is not possible, try adding a new data node to the cluster, or decrease the total cluster redundancy policy.
To check the current
redundancyPolicy
, run the following command:$ oc -n openshift-logging get es elasticsearch -o jsonpath='{.spec.redundancyPolicy}'
If you are using a
ClusterLogging
resource on your cluster, run the following command:$ oc -n openshift-logging get cl \ -o jsonpath='{.items[*].spec.logStore.elasticsearch.redundancyPolicy}'
If the cluster
redundancyPolicy
value is higher than theSingleRedundancy
value, set it to theSingleRedundancy
value and save this change.If the preceding steps do not fix the issue, delete the old indices.
Check the status of all indices on Elasticsearch by running the following command:
$ oc exec -n openshift-logging -c elasticsearch $ES_POD_NAME -- indices
- Identify an old index that can be deleted.
Delete the index by running the following command:
$ oc exec -n openshift-logging -c elasticsearch $ES_POD_NAME \ -- es_util --query=<elasticsearch_index_name> -X DELETE
Additional resources
4.3.10. Elasticsearch FileDescriptor usage is high
Based on current usage trends, the predicted number of file descriptors on the node is insufficient. Check the value of max_file_descriptors
for each node as described in the Elasticsearch File Descriptors documentation.
4.4. Viewing the status of the Elasticsearch log store
You can view the status of the OpenShift Elasticsearch Operator and for a number of Elasticsearch components.
4.4.1. Viewing the status of the Elasticsearch log store
You can view the status of the Elasticsearch log store.
Prerequisites
- The Red Hat OpenShift Logging Operator and OpenShift Elasticsearch Operator are installed.
Procedure
Change to the
openshift-logging
project by running the following command:$ oc project openshift-logging
To view the status:
Get the name of the Elasticsearch log store instance by running the following command:
$ oc get Elasticsearch
Example output
NAME AGE elasticsearch 5h9m
Get the Elasticsearch log store status by running the following command:
$ oc get Elasticsearch <Elasticsearch-instance> -o yaml
For example:
$ oc get Elasticsearch elasticsearch -n openshift-logging -o yaml
The output includes information similar to the following:
Example output
status: 1 cluster: 2 activePrimaryShards: 30 activeShards: 60 initializingShards: 0 numDataNodes: 3 numNodes: 3 pendingTasks: 0 relocatingShards: 0 status: green unassignedShards: 0 clusterHealth: "" conditions: [] 3 nodes: 4 - deploymentName: elasticsearch-cdm-zjf34ved-1 upgradeStatus: {} - deploymentName: elasticsearch-cdm-zjf34ved-2 upgradeStatus: {} - deploymentName: elasticsearch-cdm-zjf34ved-3 upgradeStatus: {} pods: 5 client: failed: [] notReady: [] ready: - elasticsearch-cdm-zjf34ved-1-6d7fbf844f-sn422 - elasticsearch-cdm-zjf34ved-2-dfbd988bc-qkzjz - elasticsearch-cdm-zjf34ved-3-c8f566f7c-t7zkt data: failed: [] notReady: [] ready: - elasticsearch-cdm-zjf34ved-1-6d7fbf844f-sn422 - elasticsearch-cdm-zjf34ved-2-dfbd988bc-qkzjz - elasticsearch-cdm-zjf34ved-3-c8f566f7c-t7zkt master: failed: [] notReady: [] ready: - elasticsearch-cdm-zjf34ved-1-6d7fbf844f-sn422 - elasticsearch-cdm-zjf34ved-2-dfbd988bc-qkzjz - elasticsearch-cdm-zjf34ved-3-c8f566f7c-t7zkt shardAllocationEnabled: all
- 1
- In the output, the cluster status fields appear in the
status
stanza. - 2
- The status of the Elasticsearch log store:
- The number of active primary shards.
- The number of active shards.
- The number of shards that are initializing.
- The number of Elasticsearch log store data nodes.
- The total number of Elasticsearch log store nodes.
- The number of pending tasks.
-
The Elasticsearch log store status:
green
,red
,yellow
. - The number of unassigned shards.
- 3
- Any status conditions, if present. The Elasticsearch log store status indicates the reasons from the scheduler if a pod could not be placed. Any events related to the following conditions are shown:
- Container Waiting for both the Elasticsearch log store and proxy containers.
- Container Terminated for both the Elasticsearch log store and proxy containers.
- Pod unschedulable. Also, a condition is shown for a number of issues; see Example condition messages.
- 4
- The Elasticsearch log store nodes in the cluster, with
upgradeStatus
. - 5
- The Elasticsearch log store client, data, and master pods in the cluster, listed under
failed
,notReady
, orready
state.
4.4.1.1. Example condition messages
The following are examples of some condition messages from the Status
section of the Elasticsearch instance.
The following status message indicates that a node has exceeded the configured low watermark, and no shard will be allocated to this node.
status: nodes: - conditions: - lastTransitionTime: 2019-03-15T15:57:22Z message: Disk storage usage for node is 27.5gb (36.74%). Shards will be not be allocated on this node. reason: Disk Watermark Low status: "True" type: NodeStorage deploymentName: example-elasticsearch-cdm-0-1 upgradeStatus: {}
The following status message indicates that a node has exceeded the configured high watermark, and shards will be relocated to other nodes.
status: nodes: - conditions: - lastTransitionTime: 2019-03-15T16:04:45Z message: Disk storage usage for node is 27.5gb (36.74%). Shards will be relocated from this node. reason: Disk Watermark High status: "True" type: NodeStorage deploymentName: example-elasticsearch-cdm-0-1 upgradeStatus: {}
The following status message indicates that the Elasticsearch log store node selector in the custom resource (CR) does not match any nodes in the cluster:
status: nodes: - conditions: - lastTransitionTime: 2019-04-10T02:26:24Z message: '0/8 nodes are available: 8 node(s) didn''t match node selector.' reason: Unschedulable status: "True" type: Unschedulable
The following status message indicates that the Elasticsearch log store CR uses a non-existent persistent volume claim (PVC).
status: nodes: - conditions: - last Transition Time: 2019-04-10T05:55:51Z message: pod has unbound immediate PersistentVolumeClaims (repeated 5 times) reason: Unschedulable status: True type: Unschedulable
The following status message indicates that your Elasticsearch log store cluster does not have enough nodes to support the redundancy policy.
status: clusterHealth: "" conditions: - lastTransitionTime: 2019-04-17T20:01:31Z message: Wrong RedundancyPolicy selected. Choose different RedundancyPolicy or add more nodes with data roles reason: Invalid Settings status: "True" type: InvalidRedundancy
This status message indicates your cluster has too many control plane nodes:
status: clusterHealth: green conditions: - lastTransitionTime: '2019-04-17T20:12:34Z' message: >- Invalid master nodes count. Please ensure there are no more than 3 total nodes with master roles reason: Invalid Settings status: 'True' type: InvalidMasters
The following status message indicates that Elasticsearch storage does not support the change you tried to make.
For example:
status: clusterHealth: green conditions: - lastTransitionTime: "2021-05-07T01:05:13Z" message: Changing the storage structure for a custom resource is not supported reason: StorageStructureChangeIgnored status: 'True' type: StorageStructureChangeIgnored
The reason
and type
fields specify the type of unsupported change:
StorageClassNameChangeIgnored
- Unsupported change to the storage class name.
StorageSizeChangeIgnored
- Unsupported change the storage size.
StorageStructureChangeIgnored
Unsupported change between ephemeral and persistent storage structures.
ImportantIf you try to configure the
ClusterLogging
CR to switch from ephemeral to persistent storage, the OpenShift Elasticsearch Operator creates a persistent volume claim (PVC) but does not create a persistent volume (PV). To clear theStorageStructureChangeIgnored
status, you must revert the change to theClusterLogging
CR and delete the PVC.
4.4.2. Viewing the status of the log store components
You can view the status for a number of the log store components.
- Elasticsearch indices
You can view the status of the Elasticsearch indices.
Get the name of an Elasticsearch pod:
$ oc get pods --selector component=elasticsearch -o name
Example output
pod/elasticsearch-cdm-1godmszn-1-6f8495-vp4lw pod/elasticsearch-cdm-1godmszn-2-5769cf-9ms2n pod/elasticsearch-cdm-1godmszn-3-f66f7d-zqkz7
Get the status of the indices:
$ oc exec elasticsearch-cdm-4vjor49p-2-6d4d7db474-q2w7z -- indices
Example output
Defaulting container name to elasticsearch. Use 'oc describe pod/elasticsearch-cdm-4vjor49p-2-6d4d7db474-q2w7z -n openshift-logging' to see all of the containers in this pod. green open infra-000002 S4QANnf1QP6NgCegfnrnbQ 3 1 119926 0 157 78 green open audit-000001 8_EQx77iQCSTzFOXtxRqFw 3 1 0 0 0 0 green open .security iDjscH7aSUGhIdq0LheLBQ 1 1 5 0 0 0 green open .kibana_-377444158_kubeadmin yBywZ9GfSrKebz5gWBZbjw 3 1 1 0 0 0 green open infra-000001 z6Dpe__ORgiopEpW6Yl44A 3 1 871000 0 874 436 green open app-000001 hIrazQCeSISewG3c2VIvsQ 3 1 2453 0 3 1 green open .kibana_1 JCitcBMSQxKOvIq6iQW6wg 1 1 0 0 0 0 green open .kibana_-1595131456_user1 gIYFIEGRRe-ka0W3okS-mQ 3 1 1 0 0 0
- Log store pods
You can view the status of the pods that host the log store.
Get the name of a pod:
$ oc get pods --selector component=elasticsearch -o name
Example output
pod/elasticsearch-cdm-1godmszn-1-6f8495-vp4lw pod/elasticsearch-cdm-1godmszn-2-5769cf-9ms2n pod/elasticsearch-cdm-1godmszn-3-f66f7d-zqkz7
Get the status of a pod:
$ oc describe pod elasticsearch-cdm-1godmszn-1-6f8495-vp4lw
The output includes the following status information:
Example output
.... Status: Running .... Containers: elasticsearch: Container ID: cri-o://b7d44e0a9ea486e27f47763f5bb4c39dfd2 State: Running Started: Mon, 08 Jun 2020 10:17:56 -0400 Ready: True Restart Count: 0 Readiness: exec [/usr/share/elasticsearch/probe/readiness.sh] delay=10s timeout=30s period=5s #success=1 #failure=3 .... proxy: Container ID: cri-o://3f77032abaddbb1652c116278652908dc01860320b8a4e741d06894b2f8f9aa1 State: Running Started: Mon, 08 Jun 2020 10:18:38 -0400 Ready: True Restart Count: 0 .... Conditions: Type Status Initialized True Ready True ContainersReady True PodScheduled True .... Events: <none>
- Log storage pod deployment configuration
You can view the status of the log store deployment configuration.
Get the name of a deployment configuration:
$ oc get deployment --selector component=elasticsearch -o name
Example output
deployment.extensions/elasticsearch-cdm-1gon-1 deployment.extensions/elasticsearch-cdm-1gon-2 deployment.extensions/elasticsearch-cdm-1gon-3
Get the deployment configuration status:
$ oc describe deployment elasticsearch-cdm-1gon-1
The output includes the following status information:
Example output
.... Containers: elasticsearch: Image: registry.redhat.io/openshift-logging/elasticsearch6-rhel8 Readiness: exec [/usr/share/elasticsearch/probe/readiness.sh] delay=10s timeout=30s period=5s #success=1 #failure=3 .... Conditions: Type Status Reason ---- ------ ------ Progressing Unknown DeploymentPaused Available True MinimumReplicasAvailable .... Events: <none>
- Log store replica set
You can view the status of the log store replica set.
Get the name of a replica set:
$ oc get replicaSet --selector component=elasticsearch -o name replicaset.extensions/elasticsearch-cdm-1gon-1-6f8495 replicaset.extensions/elasticsearch-cdm-1gon-2-5769cf replicaset.extensions/elasticsearch-cdm-1gon-3-f66f7d
Get the status of the replica set:
$ oc describe replicaSet elasticsearch-cdm-1gon-1-6f8495
The output includes the following status information:
Example output
.... Containers: elasticsearch: Image: registry.redhat.io/openshift-logging/elasticsearch6-rhel8@sha256:4265742c7cdd85359140e2d7d703e4311b6497eec7676957f455d6908e7b1c25 Readiness: exec [/usr/share/elasticsearch/probe/readiness.sh] delay=10s timeout=30s period=5s #success=1 #failure=3 .... Events: <none>
4.4.3. Elasticsearch cluster status
A dashboard in the Observe section of the OpenShift Container Platform web console displays the status of the Elasticsearch cluster.
To get the status of the OpenShift Elasticsearch cluster, visit the dashboard in the Observe section of the OpenShift Container Platform web console at <cluster_url>/monitoring/dashboards/grafana-dashboard-cluster-logging
.
Elasticsearch status fields
eo_elasticsearch_cr_cluster_management_state
Shows whether the Elasticsearch cluster is in a managed or unmanaged state. For example:
eo_elasticsearch_cr_cluster_management_state{state="managed"} 1 eo_elasticsearch_cr_cluster_management_state{state="unmanaged"} 0
eo_elasticsearch_cr_restart_total
Shows the number of times the Elasticsearch nodes have restarted for certificate restarts, rolling restarts, or scheduled restarts. For example:
eo_elasticsearch_cr_restart_total{reason="cert_restart"} 1 eo_elasticsearch_cr_restart_total{reason="rolling_restart"} 1 eo_elasticsearch_cr_restart_total{reason="scheduled_restart"} 3
es_index_namespaces_total
Shows the total number of Elasticsearch index namespaces. For example:
Total number of Namespaces. es_index_namespaces_total 5
es_index_document_count
Shows the number of records for each namespace. For example:
es_index_document_count{namespace="namespace_1"} 25 es_index_document_count{namespace="namespace_2"} 10 es_index_document_count{namespace="namespace_3"} 5
The "Secret Elasticsearch fields are either missing or empty" message
If Elasticsearch is missing the admin-cert
, admin-key
, logging-es.crt
, or logging-es.key
files, the dashboard shows a status message similar to the following example:
message": "Secret \"elasticsearch\" fields are either missing or empty: [admin-cert, admin-key, logging-es.crt, logging-es.key]", "reason": "Missing Required Secrets",