As part of bug 1268484 and deps, an experimental fuzzy matcher was added to auto-classify (alongside the other matcher types) that uses Elasticsearch for word-only matching. Since the feature was experimental, it was made to be optional - and only enabled if the ELASTICSEARCH_URL environment variable is set (which points at an Elasticsearch server instance).

Status of the feature across environments:

• Vagrant: Feature enabled (ie: Elasticsearch server installed and environment variable set)
• Travis: Feature enabled
• treeherder-prototype: Has been enabled on and off, most recently disabled in bug 1340552 comment 4
• treeherder-stage: Never enabled
• treeherder-prod: Never enabled

This means that our CI and local development environment currently isn't running the same feature-set as prototype/stage/prod, which isn't ideal.

I think we should disable it everywhere for now to increase parity between environments.
(It also will be one less thing to worry about for bug 1169263.)

https://github.com/mozilla/treeherder/commit/681cc6d54f04526d507318404adcc876840d9e62
https://github.com/mozilla/treeherder/commit/86b7b32fd1889dbc7d3b350515ed7a5f1549bb0e