Non-durable postgres for e2e tests

08/01/2020

During e2e testing we can sacrifice postgres durability in favour of performance. Durability guarantees the saving of data even if the server crashes or loses power, which is not usually needed during e2e tests. It’s arguable that e2e tests should test a system as close to production as possible, but I think if you need to speed up your tests this is a worthy trade-off.

Simply add the following to the /var/lib/postgresql/data/postgresql.conf file:

fsync = off
synchronous_commit = off
full_page_writes = off

Note that fsync can only be set in the postgresql.conf or on the server command line.

Using these settings we were able to decrease our test running time by ~20%. Given that our e2e tests are not all db focused, I think this is a good result.

A non durable postgres docker image can be found here: https://hub.docker.com/repository/docker/shusson/nd-postgres