Merge pull request #8059 from openshift-cherrypick-robot/cherry-pick-7778-to-enterprise-3.9

[enterprise-3.9] Bug 1314564 Add Instructions to Scale EFK Pods When Changes are Made

Author: bmcelvee

install_config/aggregate_logging.adoc

@@ -1178,6 +1178,51 @@ test-project:
   read_lines_limit: 100
 ----
 ====
+
+When you make changes to any part of the EFK stack, specifically Elasticsearch
+or Fluentd, you should first scale Elasicsearch down to zero and scale Fluentd
+so it does not match any other nodes. Then, make the changes and scale
+Elasicsearch and Fluentd back.
+
+To scale Elasicsearch to zero:
+----
+$ oc scale --replicas=0 dc/<ELASTICSEARCH_DC>
+----
+
+Change nodeSelector in the daemonset configuration to match zero:
+
+.Get the fluentd node selector:
+----
+$ oc get ds logging-fluentd -o yaml |grep -A 1 Selector
+     nodeSelector:
+       logging-infra-fluentd: "true"
+----
+
+.Use the `oc patch` command to modify the daemonset nodeSelector:
+----
+$ oc patch ds logging-fluentd -p '{"spec":{"template":{"spec":{"nodeSelector":{"nonexistlabel":"true"}}}}}'
+----
+
+.Get the fluentd node selector:
+----
+$ oc get ds logging-fluentd -o yaml |grep -A 1 Selector
+     nodeSelector:
+       "nonexistlabel: "true"
+----
+
+Scale Elastcsearch back up from zero:
+----
+$ oc scale --replicas=# dc/<ELASTICSEARCH_DC>
+----
+
+Change nodeSelector in the daemonset configuration back to
+logging-infra-fluentd: "true".
+
+Use the `oc patch` command to modify the daemonset nodeSelector:
+----
+oc patch ds logging-fluentd -p '{"spec":{"template":{"spec":{"nodeSelector":{"logging-infra-fluentd":"true"}}}}}'
+----
+
 [[aggregate-logging-kibana]]
 === Kibana