ElasticSearch entered "read only" mode, node cannot be altered
The correct command is:
PUT /_cluster/settings{ "persistent" : { "cluster.blocks.read_only" : false }}
It turns out ES has some thresholds for available disk space, and when the "flood" one is hit, it puts the indeces into read only mode.
In order to set it back (tested with ES6), you will need to do the following:
PUT /[index_name]/_settings{ "index.blocks.read_only_allow_delete": null}More information can be found on the following page of the documentation:https://www.elastic.co/guide/en/elasticsearch/reference/current/disk-allocator.html