adding support for aioredis (#534)

[yoav-orca]

An initial PR for adding support aioredis, ref #534 I have encountered an unfortunate limitation.
When using:

# view code

async def redis_pool():
    # Redis client bound to pool of connections (auto-reconnecting).
    redis = await aioredis.create_redis_pool(
        'redis://localhost')
    await redis.set('my-key', 'value')
    val = await redis.get('my-key')
    print(val)

    # gracefully closing underlying connection
    redis.close()
    await redis.wait_closed()

def index(request):
    loop = get_event_loop()
    loop.run_until_complete(redis_pool())

Looking at the trace it seems that scout doesn't recognize that the task is coming from the same thread (the trace is missing the aioredis) segment.

This has already an issue #469

When using async_to_sync it works

[yoav-orca]

@adamchainz what do you think?

[adamchainz]

Hi @yoav-orca

Sorry I didn't respond until now - I went on holiday and your PR was one of many things to respond to.

Thanks for making this. It has certainly exposed the places in aioredis to instrument.

Yes there's still the problem from #469. This needs more research to overcome before we can merge anything.

One thing about your PR - our instruments are per library rather than per "technology", so this should be an "aioredis" instrument. Rather than push to your master branch, I've done this in #562 (maintaining your orignal authorship). As such I'm going to close this PR and continue working on the other PR.

We have some other higher priority work around making the launching the core agent more stable, which I'll be addressing first, but I should find time in the next few weeks to revisit aioredis.

Thanks,

Adam