fix(log): set info log level by default for the entire application

[bnjjj]

By default the log level of the application if RUST_LOG is not set is info and if you provide --log or APOLLO_RUST_LOG value then it overrides the default info log level with apollo_router=... because it only impacts the apollo_router crate, not external custom plugin and so one.

By doing this fix, by default if you have a custom plugin with info logs or metrics you won't have to enforce RUST_LOG=info everytime, it will work as expected.

Note: it doesn't impact the behavior of RUST_LOG if you set it.

Checklist

Complete the checklist (and note appropriate exceptions) before the PR is marked ready-for-review.

• Changes are compatible¹
• Documentation² completed
• Performance impact assessed and acceptable
• Tests added and passing³
  • Unit Tests
  • Integration Tests
  • Manual Tests

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Notes

Footnotes

1. It may be appropriate to bring upcoming changes to the attention of other (impacted) groups. Please endeavour to do this before seeking PR approval. The mechanism for doing this will vary considerably, so use your judgement as to how and when to do this. ↩

2. Configuration is an important part of many changes. Where applicable please try to document configuration examples. ↩

3. Tick whichever testing boxes are applicable. If you are adding Manual Tests, please document the manual testing (extensively) in the Exceptions. ↩

[router-perf]

CI performance tests

• events_big_cap_high_rate - Stress test for events with a lot of users, deduplication enabled and high rate event with a big queue capacity
• events_without_dedup - Stress test for events with a lot of users and deduplication DISABLED
• events - Stress test for events with a lot of users and deduplication ENABLED
• large-request - Stress test with a 1 MB request payload
• step - Basic stress test that steps up the number of users over time
• xlarge-request - Stress test with 10 MB request payload
• reload - Reload test over a long period of time at a constant rate of users
• no-graphos - Basic stress test, no GraphOS.
• events_callback - Stress test for events with a lot of users and deduplication ENABLED in callback mode
• xxlarge-request - Stress test with 100 MB request payload
• step-jemalloc-tuning - Clone of the basic stress test for jemalloc tuning
• events_without_dedup_callback - Stress test for events with a lot of users and deduplication DISABLED using callback mode
• const - Basic stress test that runs with a constant number of users
• events_big_cap_high_rate_callback - Stress test for events with a lot of users, deduplication enabled and high rate event with a big queue capacity using callback mode

[BrynCooke]

The docs need to updated:
https://www.apollographql.com/docs/router/configuration/telemetry/exporters/logging/overview/#log-level

Also @garypen do you agree with the overall change?

[bnjjj]

@BrynCooke I think the documentation is still accurate, I didn't change the behavior. I just fixed it

[garypen]

The docs need to updated: https://www.apollographql.com/docs/router/configuration/telemetry/exporters/logging/overview/#log-level

Also @garypen do you agree with the overall change?

The motivation of the last adjustment to APOLLO_ROUTER_LOG was to limit its scope to "just router stuff". We restored RUST_LOG functionality to what a rust developer would expect (i.e.: you can do whatever is supported by the RUST_LOG filtering). I think there was an oversight in that fix which mean that APOLLO_ROUTER_LOG didn't apply to plugins, so if you wanted to see logs from plugins you had to use RUST_LOG.

If this fix is addressing that shortcoming, i.e.: plugins observe the same logging behaviour as the main router, then that is correct.

It looks to me like it might also change the value for non-plugin crates, e.g.: hyper, and, if it does, then I don't think that would be desirable.

[bnjjj]

@garypen

If this fix is addressing that shortcoming, i.e.: plugins observe the same logging behaviour as the main router, then that is correct.

That's the goal yes.

It looks to me like it might also change the value for non-plugin crates, e.g.: hyper, and, if it does, then I don't think that would be desirable.

I don't think it will change the value for non plugin crate like hyper because by default it's set to info. That's what I'm doing basically, making sure the default is still info even if we set a specific log level for apollo router and plugins.