Undefined Description
GitHub issue:
https://github.com/openshift/openshift-docs/issues/44965
Which section(s) is the issue in?
https://docs.openshift.com/container-platform/4.10/logging/cluster-logging-release-notes.html#cluster-logging-supported-versions
https://docs.openshift.com/container-platform/4.8/logging/cluster-logging-release-notes.html#openshift-logging-supported-versions
What needs fixing?
In OCP 4.8 documents, RHOL version matrix says that RHOL 5.3 is supported for OCP 4.8. But the same matrix for OCP 4.10 it says that RHOL 5.3 is not supported for OCP 4.8. We made RHOL operator upgrades to version 5.3 from 4.6 for our OCP 4.8 clusters relying on this document and Fluentd ignored .pos files and started to read all logs, caused high load on elasticsearch.
As we investigated this issue, there was an "outstanding work" on Fluentd below. According to this work, .pos file paths have changed and old files would be copied to new paths. But it didn't happened on our upgrades and Fluentd started to read all logs from beginings.
https://issues.redhat.com/browse/LOG-1311
Command outputs for RHOL 4.6:
{{[root@localhost ~]# oc get csv
NAME DISPLAY VERSION REPLACES PHASE
clusterlogging.4.6.0-202112031823 Cluster Logging 4.6.0-202112031823 clusterlogging.4.6.0-202111191944 Succeeded
elasticsearch-operator.5.3.6-46 OpenShift Elasticsearch Operator 5.3.6-46 elasticsearch-operator.4.6.0-202112140939 Succeeded
[root@localhost ~]# oc exec fluentd-49vlx – wc -l /var/log/es-containers.log.pos ; echo ; wc -l /var/lib/fluentd/pos ; echo
103 /var/log/es-containers.log.pos
wc: /var/lib/fluentd/pos: No such file or directory}}
Command outputs for RHOL 5.3:
{{[root@localhost ~]# oc get csv
NAME DISPLAY VERSION REPLACES PHASE
cluster-logging.5.3.6-46 Red Hat OpenShift Logging 5.3.6-46 cluster-logging.5.2.9-42 Succeeded
elasticsearch-operator.5.3.6-46 OpenShift Elasticsearch Operator 5.3.6-46 elasticsearch-operator.4.6.0-202112140939 Succeeded
sh-4.4# wc -l /var/log/es-containers.log.pos ; echo ; wc -l /var/lib/fluentd/pos/*
256 /var/log/es-containers.log.pos
1 /var/lib/fluentd/pos/audit.log.pos
11 /var/lib/fluentd/pos/es-containers.log.pos
0 /var/lib/fluentd/pos/journal_pos.json
1 /var/lib/fluentd/pos/kube-apiserver.audit.log.pos
13 total}}