remove objects from array elastic search

Question

I have required to remove object from array that satisfies the condition, I am able to update the object of array on the basis of condition, which is as follow:

PUT twitter/twit/1
{"list": 
     [
        {
            "tweet_id": "1",
            "a": "b"
        },
        {
            "tweet_id": "123",
            "a": "f"
        }
    ]
}

POST /twitter/twit/1/_update
{"script":"foreach (item :ctx._source.list) {
                if item['tweet_id'] == tweet_id) {
                      item['new_field'] = 'ghi';
                }
           }",
 "params": {tweet_id": 123"}
}

this is working

for remove i am doing this

POST /twitter/twit/1/_update
{ "script": "foreach (item : ctx._source.list) {
                    if item['tweet_id'] == tweet_id) {
                          ctx._source.list.remove(item); 
                    }
            }",
  "params": { tweet_id": "123" }
}

but this is not working and giving this error,

ElasticsearchIllegalArgumentException[failed to execute script]; nested: ConcurrentModificationException; Error: ElasticsearchIllegalArgumentException[failed to execute script]; nested: ConcurrentModificationException

I am able to remove whole array or whole field using

"script": "ctx._source.remove('list')"

I am also able to remove object from array by specifying all the keys of an object using

"script":"ctx._source.list.remove(tag)",
     "params" : {
        "tag" : {"tweet_id": "123","a": "f"}

my node module elastic search version is 2.4.2 elastic search server is 1.3.2

Answer 1

You get that because you are trying to modify a list while iterating through it, meaning you want to change a list of object and, at the same time, listing those objects.

You instead need to do this:

POST /twitter/twit/1/_update
{
  "script": "item_to_remove = nil; foreach (item : ctx._source.list) { if (item['tweet_id'] == tweet_id) { item_to_remove=item; } } if (item_to_remove != nil) ctx._source.list.remove(item_to_remove);",
  "params": {"tweet_id": "123"}
}

If you have more than one item that matches the criteria, use a list instead:

POST /twitter/twit/1/_update
{
  "script": "items_to_remove = []; foreach (item : ctx._source.list) { if (item['tweet_id'] == tweet_id) { items_to_remove.add(item); } } foreach (item : items_to_remove) {ctx._source.list.remove(item);}",
  "params": {"tweet_id": "123"}
}