Access token mongodb service creates index excessively

[kroepke]

Expected Behavior

The database index should only be created once, to ensure there's a unique index on the collection.

Current Behavior

Every time a token is a saved, including when its access time is updated, the index gets recreated.
This leads to at least an additional table lock, and extra work on index creation in the background. On systems with lots of sidecars this creates performance problems.

Possible Solution

In https://github.com/Graylog2/graylog2-server/blob/master/graylog2-server/src/main/java/org/graylog2/security/AccessTokenServiceImpl.java#L142 move the createIndex call to the constructor.

Steps to Reproduce (for bugs)

Code pointer above.

Context

Each access token use will save it to the database, leading to excessive queries.

Your Environment

• Graylog Version: reported in 4.3 but applicable to all versions