Blog

At work I still run the Elasticsearch Cluster in version 5.6.4. While I’m eager to upgrade and keep up the pace, I don’t always have the chance to upgrade immediately. A customer of mine needed a small set of data in Excel. Elasticsearch 6 or moreover Kibana 6 offers the CSV export in the X-Pack extensions. To use that functionality, I needed to export a fragment of desired data from my production cluster. Since the Reindex API allows us to read data from remote and write it, I simply ramped up my private cluster in v 6.1.1 with Docker and started the reindexing.

Providing a HTTP health check service with Nginx, is straightforward. If you do ensure that Nginx closes the HTTP connection instead keeping it alive. The basic option therefore is:

Performing a reindex job in Elasticsearch gives you the time the job took.

Find ObjectId of the chat room

> db.rooms.find({slug:"elk"}).pretty()
{
        "_id" : ObjectId("59a666cfa9886c002c30b404"),
        "owner" : ObjectId("59a547c2aed276003facf84f"),
        "name" : "Elasticschrott",
        "slug" : "elk",
        "description" : "Everything about the Elasticsearch Universe, including Logstash, Beats",
        "private" : false,
        "lastActive" : ISODate("2017-08-31T08:46:33.690Z"),
        "created" : ISODate("2017-08-30T07:18:39.885Z"),
        "messages" : [ ],
        "participants" : [ ],
        "archived" : true,
        "__v" : 0
}

A chat room in letschat was archived. To revive it we can alter the document in the MongoDB instance.

I got this situation in a log file, where the JSON information is after the grep output of the file name.

Running Elasticsearch Service on AWS (Amazon Web Services)

In short: Converting a UTC timestamp to a local timestamp (in Switzerland).

Elasticsearch with its Query DSL allows powerful aggregations in order to save documents and disk space. After a certain period of time a certain level of detail is not needed anymore. For instance, I collect on a daily basis statistical data about fraud prevention services.