What happens when I insert 2 documents with same id in ElasticSearch?-CodePudding

I would like to know what happens when I add a document with an existing id in the same index.

I know that it won't be repeated, what I don't know is if Elasticsearch will ignore the latter or if it will update the first one.

Thank you very much.

CodePudding user response：

The latest document will simply override the previous one having the same ID and the version count will be bumped by 1.

It's easy to test:

# 1. create the document
PUT test/_doc/1
{
  "test": "me"
}

# 2. response from the creation
{
  "_index" : "test",
  "_type" : "_doc",
  "_id" : "1",
  "_version" : 1,               <---- check this
  "result" : "created",         <---- check this
  "_shards" : {
    "total" : 2,
    "successful" : 2,
    "failed" : 0
  },
  "_seq_no" : 0,
  "_primary_term" : 1
}

# 3. update the document
PUT test/_doc/1
{
  "test": "me2"
}

# 4. response from the update
{
  "_index" : "test",
  "_type" : "_doc",
  "_id" : "1",
  "_version" : 2,               <---- check this
  "result" : "updated",         <---- check this
  "_shards" : {
    "total" : 2,
    "successful" : 2,
    "failed" : 0
  },
  "_seq_no" : 1,
  "_primary_term" : 1
}