1291035 - Increase requests pool size in decision task

Status: RESOLVED FIXED

(Firefox Build System :: Task Configuration, task)

Description

[Gregory Szorc [:gps]]

More follow-up work from making the decision task make HTTP requests concurrently. Patch forthcoming.

Comment 1

[Gregory Szorc [:gps]]

Attachment: Bug 1291035 - Increase HTTP connection pool capacity;

I was looking at some decision task logs and noticed lines like:

  Connection pool is full, discarding connection: taskcluster

I also noticed lines like:

  Starting new HTTP connection (153): taskcluster

In this case, we had established 153 TCP connections to a server.

Looking at the requests source code, a requests.session by default
creates a connection pool with capacity of 10. There are actually 2
components to the capacity: idle connections and active connections.
What appeared to be happening was we could obtain an idle connection,
use it, and then it would be discarded when put back in the idle
pool because the idle pool was at capacity. Furthermore, it also
appears that connections were sitting around waiting for a TCP
connection.

This commit uses a custom "adapter" with an increased pool size that
matches the concurrency level of the code issuing the HTTP requests.
This should increase the number of concurrent TCP connections / requests,
decreease the number of TCP connections being used overall, and make
decision tasks complete faster.

Review commit: https://reviewboard.mozilla.org/r/68416/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/68416/

Comment 2

[Dustin J. Mitchell [:dustin] (he/him)]

Comment on attachment 8776717 [details]
Bug 1291035 - Increase HTTP connection pool capacity;

https://reviewboard.mozilla.org/r/68416/#review65486

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/1eb53cee97d3
Increase HTTP connection pool capacity; r=dustin

Comment 4

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/1eb53cee97d3