Users and Pages are not Visible

Issue

The components User, UserGroup, and Layout have been re-indexed. However, Users and Pages are still not visible.

The possible cause of this is due to the cluster health as the red or yellow cluster status indicates one or more shards are missing or un-allocated. These unassigned shards increase the risk of data loss and can degrade cluster performance.
If cluster health is red, as a first step, user may try restarting the Elasticsearch server and check the cluster status then verify the Liferay behavior. Additionally, check these official Elasticsearch documents as it is more specific to the search server.
diagnose-cluster-status
fix-red-yellow-cluster-status
Now, check the elastic search logs:
```
Failed to execute phase [query], all shards failed
Failed to execute phase [query], all shards failed
```
```
high disk watermark [90%] exceeded […] shards will be relocated away from this node
```
The cluster health status is red, all shards failed and for high disk watermark, the disk size need to be increased where the elastic search server is installed.
- Post changes, restart the server and check for high disk watermark WARN and shard fail messages.

For the longer run, users need to discuss with their infra and architect team to stabilize the elastic search server.