Pin.override not working for pymemcached when using HashClient

[damjankuznar]

Summary of problem

Pin.override not working for pymemcached lib when using HashClient. This is further complicated when setting use_pooling=True which then dynamically creates client connections. Being able to only override service name for Client instances is not really useful since any kind of serious use of pymemcached will involve a Memcached cluster and use of HashClient.

Which version of dd-trace-py are you using?

1.12.0

Which version of pip are you using?

22.3.1

Which libraries and their versions are you using?

`pip freeze`

ddtrace==1.12.0 pymemcache==4.0.0

How can we reproduce your problem?

Minimal example to demonstrate the issue:

from ddtrace import Pin
from pymemcache import HashClient

servers = ["localhost:11211"]

client = HashClient(servers=servers, use_pooling=True)

Pin.override(client, service="memcached-hashclient-pooling")

# still reports as `memcached` service in DataDog
client.set("test", "value")

Only Client class is patched and that doesn't work well with overriding since client connections are created dynamically in HashClient and PooledClient class.

What is the result that you get?

After using Pin.override on HashClient instance ddtrace still reports traces as memcached service in DataDog.

What is the result that you expected?

I would expect that I could override service name for HashClient.

[emmettbutler]

@damjankuznar thank you for reporting this issue. We'll take a look and see if we can implement a fix.

[emmettbutler]

@damjankuznar After looking into this more closely, I discovered that there is an undocumented way to override the service name on HashClient instances. Instead of overriding the pin on the HashClient itself, you should do so on each of its held Client instances:

for _c in client.clients.values():
    Pin.override(_c, service="my-service")

I'm going to close this ticket to indicate that the issue has been addressed. Please reopen if you disagree, and thanks again!

[damjankuznar]

I tried that but it doesn't work with use_pooling=True argument since it's using PooledClient in that case, which also doesn't have support for Pin.override.

Note: I can't reopen the issue myself.

[emmettbutler]

@damjankuznar My mistake, sorry about that.

Does this test accurately replicate the use case you're looking for?