Elasticsearch index last update time

Question

Is there a way to retrieve from ElasticSearch information on when a specific index was last updated? My goal is to be able to tell when it was the last time that any documents were inserted/updated/deleted in the index. If this is not possible, is there something I can add in my index modification requests that will provide this information later on?

Answer 1

You can get the modification time from the _timestamp

To make it easier to return the timestamp you can set up Elasticsearch to store it:

curl -XPUT "http://localhost:9200/myindex/mytype/_mapping" -d'
{
  "mytype": {
      "_timestamp": {
          "enabled": "true",
          "store": "yes"
      }
  }
}'

If I insert a document and then query on it I get the timestamp:

 curl -XGET 'http://localhost:9200/myindex/mytype/_search?pretty' -d '{
>  fields : ["_timestamp"],
>    "query": {
>     "query_string": { "query":"*"}
>    }
> }'
{
   "took" : 7,
  "timed_out" : false,
  "_shards" : {
    "total" : 5,
    "successful" : 5,
    "failed" : 0
  },
  "hits" : {
     "total" : 1,
     "max_score" : 1.0,
     "hits" : [ {
       "_index" : "myindex",
       "_type" : "mytype",
       "_id" : "1",
       "_score" : 1.0,
       "fields" : {
        "_timestamp" : 1417599223918
      }
    } ]
  }
}

updating the existing document:

curl -XPOST "http://localhost:9200/myindex/mytype/1/_update" -d'
{
  "doc" : {
      "field1": "data",
      "field2": "more data"
  },
  "doc_as_upsert" : true
}'

Re-running the previous query shows me an updated timestamp:

  "fields" : {
    "_timestamp" : 1417599620167
  }