List all active clients

[skrystosik]

Hi guys,
I need to list and iterate through all existing clients from ruby code. Is there any hook we can use for that? I'm checking documentation and sourcecode but can't find it.

[comandeo]

Hi @skrystosik , the driver does not keep track of existing clients. However, you can use ObjectSpace module to get Mongo::Client objects:

ObjectSpace.each_object(Mongo::Client) { |client| pp client }

[skrystosik]

Great, thank you!

[skrystosik]

I have one extra question, we're not able to hook subscriber before client is created. Can we check somehow if client has active sbuscriber to be sure that we do not start more than one at the time?

[comandeo-mongo]

If the "subscriber" means SDAM monitoring subscriber, you can use sdam_proc option to hook subscriber before client is created - see the example here. Or you can use Mongo::Monitoring::Global.subscribe.

I do not think there is a "legal" option to check monitoring subscribers of a client.

[skrystosik]

I need to add COMMAND subscriber to client running in multiple instances (passenger phusion). In theory should work there but I see subscriber added to Mongo::Monitoring::Global (in our logs) but I don't see execution of subscriber. On our environment works fine :) I need to think about it little bit