Detect changes during bulk indexing - elasticsearch

Question

We are using Elasticsearch v5.6.12 for our database. We update this frequently using the bulk REST api. Some of the time the individual requests won't change anything (i.e. the value of the document that Elasticsearch is already up to date). How can I detect these instances?
I saw this (https://www.elastic.co/guide/en/elasticsearch/reference/current/docs-update.html) but I'm not sure it's applicable in our situation.

Answer 1

You can use the noop detection when checking the result of your bulk queries.
When the bulk query returns, you can iterate over each update result and check if the result field has a value of noop (vs updated)
# Say the document is indexed
PUT test/doc/1
{
"test": "123"
}
# Now you want to bulk update it
POST test/doc/_bulk
{"update":{"_id": "1"}}
{"doc":{"test":"123"}} <-- this will yield `result: noop`
{"update":{"_id": "1"}}
{"doc":{"test":"1234"}} <-- this will yield `result: updated`
{"update":{"_id": "2"}}
{"doc":{"test":"3456"}, "doc_as_upsert": true} <-- this will yield `result: created`
Result:
{
"took" : 6,
"errors" : false,
"items" : [
{
"update" : {
"_index" : "test",
"_type" : "doc",
"_id" : "1",
"_version" : 2,
"result" : "noop", <-- see "noop"
"_shards" : {
"total" : 2,
"successful" : 1,
"failed" : 0
},
"status" : 200
}
},
{
"update" : {
"_index" : "test",
"_type" : "doc",
"_id" : "1",
"_version" : 3,
"result" : "updated", <-- see "updated"
"_shards" : {
"total" : 2,
"successful" : 1,
"failed" : 0
},
"_seq_no" : 2,
"_primary_term" : 1,
"status" : 200
}
},
{
"_index" : "test",
"_type" : "doc",
"_id" : "2",
"_version" : 1,
"result" : "created", <-- see "created"
"_shards" : {
"total" : 2,
"successful" : 1,
"failed" : 0
},
"_seq_no" : 0,
"_primary_term" : 1
}
]
}
As you can see, when specifying doc_as_upsert: true for document with id 2, the document will be created and the result field value will be created