How to stop reindexing in Elasticsearch?

Question

I've started reindexing some of my data from one index to another using the Reindex API. The problem is that now I want to stop the reindexing process, even though it has not finished. I'm able to see the process running with this command:

GET _tasks?detailed=true&actions=*reindex

But, how can I stop it?

EDIT: Stopping the whole cluster is not a possibility because it is being used for other purposes at the same time.

Answer 1

You can use the Cancel Task API if the Task is cancellable

Quoting from documentation

Any Reindex can be canceled using the Task Cancel API:

POST _tasks/node_id:task_id/_cancel

The task_id can be found using the Tasks API.

Cancelation should happen quickly but might take a few seconds. The Tasks API will continue to list the task until it wakes to cancel itself.

---

Using the command below, get the task ID and follow

GET _tasks?detailed=true&actions=*reindex

Use the id given out from the command and cancel using the Task API

 "tasks" : {
    "r1A2WoRbTwKZ516z6NEs5A:36619" : {
      "node" : "r1A2WoRbTwKZ516z6NEs5A",
      "id" : 36619,
      "type" : "transport",
      "action" : "indices:data/write/reindex",
      .....
}

Answer 2

This is the one that worked for me.

POST _tasks/_cancel?nodes=node_id&actions=*reindex