remove objects from array elastic search - node.js

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"}
}

Answer 2

For people that need this working in elasticsearch 2.0 and up, the nil and foreach don't get recognized by groovy.
So here's a updated version, including a option to replace a item with the same id by a new object.
and also passing it the upsert will make sure the item gets added even if the document doesn't exist yet
{
"script": "item_to_remove = null; ctx._source.delivery.each { elem -> if (elem.id == item_to_add.id) { item_to_remove=elem; } }; if (item_to_remove != null) ctx._source.delivery.remove(item_to_remove); if (item_to_add.size() > 1) ctx._source.delivery += item_to_add;",
"params": {"item_to_add": {"id": "5", "title": "New item"}},
"upsert": [{"id": "5", "title": "New item"}]
}