Lagom: first-time-bucket default value slows down tests.

[ignasi35]

Lagom sets the default value of

cassandra-query-journal {
  first-time-bucket = "20160225T00:00"
}

An integration test running over a clean database takes quite some time to converge from that value to now(). We should document how to hack your unit tests to take that setting to a value that speed up test.

For example, I've set first-time-bucket = "20190903T00:00" on a test today shaving around 20 seconds (from 50sec to 30sec)!

[marcospereira]

For example, I've set first-time-bucket = "20190903T00:00" on a test today shaving around 20 seconds (from 50sec to 30sec)!

shaving around 20 seconds (from 50sec to 30sec)!

20 seconds

I will have two of these, please.

[TimMoore]

It probably should be documented for more than just tests, too. I think we've seen slow-downs in production caused by not customizing this. AFAIK the Lagom docs don't say anywhere that you should.

[octonato]

For our tests, we can simply override this property with now().

Of course, documenting for users this is very important as well.

[marcospereira]

AFAIK the Lagom docs don't say anywhere that you should.

It could be a good idea to make our seeds to set this to the current time when creating a new project as well (with the generated config pointing to the docs).

[dwijnand]

Could akka-persistence-cassandra do the now() if first-time-bucket is unset and the database is clean, and then that seed value be obtainable later? Seems silly to have a database at hand and have to record this in a file while generating a project (seeing as it's not a secret password-like thing).

[patriknw]

maybe this was more than our own tests