Kibana Error: "Failed to poll for work: [cluster_block_exception] blocked by: [FORBIDDEN/12/index read-only

"Failed to poll for work: [cluster_block_exception] blocked by: [FORBIDDEN/12/index read-only

While checking the logs, one more error noticed in that.

[INFO ][o.e.c.r.a.DiskThresholdMonitor] [PMvMDFd] low disk watermark [85%] exceeded on [PMvMDFdBQ4ue5IuuRXcVSw][PMvMDFd][/var/lib/elasticsearch/nodes/0] free: 5.9gb[12.3%], replicas will not be assigned to this node

This happens when Elasticsearch thinks the disk is running low on space so it puts itself into read-only mode. It is because of the default watermark disk usage of Elastic Search and usually it is 95% of disk size.

Immediate temporary solution is to disable the read-only mode manually.

#curl -XPUT -H "Content-Type: application/json" http://localhost:9200/_all/_settings -d '{"index.blocks.read_only_allow_delete": null}'

Please note that this solution is temporary and the proper way to resolve this issue is to increase the disk space.

That's all…