ElasticSearch scribe for the Katip logging framework.

LTS Haskell 8.24:
Stackage Nightly 2017-02-11:
LTS Haskell 8.24:
Stackage Nightly 2017-02-11:
Latest on Hackage:
BSD3 licensed by Ozgun Ataman, Michael Xavier
Maintained by michael.xavier@soostone.com

Module documentation for

Katip Elasticsearch Build Status

katip-elasticsearch is a scribe for the Katip logging framework that sends structured logs to ElasticSearch.


  • Built in bounded buffering.

  • Configurable pool of logging workers to help with high write volume.

  • Optional field type annotation to avoid mistyping values.

  • Optional automatic date sharding, so logs can be filed into monthly, weekly, daily, hourly, every minute indices. You can even specify your own index routing logic. This pattern can be seen in the ELK stack as a way of keeping indexes reasonably sized and easy to optimize, rotate, and manage.

  • Customizable retry policy for temporary outages and errors.

  • Automatic index and mapping setup.


  • Update to bloodhound >= This version adds support for both ElasticSearch versions 1 and 5. Previously, we implicitly supported one and maybe would work on 5. The types in EsScribeCfg had to change to be able to specify which version was being targeted.
  • Improved documentation.

  • Widen dependency on katip

  • Loosen deps on aeson to allow

  • Loosen deps on bloodhound, aeson, and http-client.

  • Added zero padding to date-based indices. This shouldn't negatively impact most users but to be safe, this was put behind a breaking version number. Previously, you may see indices log-index-prefix-2016-1-2. That index will now be log-index-prefix-2016-01-02, so at worst when you deploy, the day of the change will have 2 indices: one zero-padded and one not. If you are using custom index sharding, you will not be affected by this. The reasoning here is that most existing elasticsearch tools such as curator expects date indices to be zero padded. By switching to the standard, users can easily get log rotation and other features from curator rather than having to roll their own or add them to Katip.

  • Drop direct dependency on random, upgrade uuid to >= 1.3.12 for safer id generation. Previously, UUID was using randomIO, which uses the system clock as a seed. So if multiple nodes happened to start at the same time, they would produce conflicting UUID sequences.

  • Default index sharding policy to daily. Previously it was no sharding. The reasoning here is that no sharding creates very large indices which become very difficult to manage in production. Rotating data out on a time basis is very slow compared to deleting date-based indices.

    Upgrade note: if you were using the defaults before and switch to daily, rather than having the index name of my-index, you'll start seeing my-index-2016-3-14. The good news is that whatever you're using to use to search against your logs (such as kibana) will support index patterns, so just use the pattern of my-index* to get everything. Eventually if you have a retention period, you can manually delete the my-index index without disruption.

  • Set upper bounds for a few dependencies.

  • Initial release
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