archive: Increase the number of backend workers

gunicorn-swh-webapp service has currently 32 workers. Cranking up from 4 to 16 will likely decrease the socket timeout occurrences [1] when a storage worker is taking longer than anticipated to give back its computation result.

• [1]

10:22 <swhbot> icinga RECOVERY: service swh-storage api (localhost) on moma.softwareheritage.org is OK: HTTP OK: HTTP/1.1 200 OK - 482 bytes in 0.001 second response time
10:23 <swhbot> icinga RECOVERY: service swh webapp content known on moma.softwareheritage.org is OK: HTTP OK: HTTP/1.1 200 OK - 530 bytes in 0.025 second response time
10:23 <swhbot> icinga RECOVERY: service swh webapp revision log end to end on moma.softwareheritage.org is OK: HTTP OK: HTTP/1.1 200 OK - 110006 bytes in 0.200 second response time

Test Plan

octocatalog-diff

diff origin/production/moma.softwareheritage.org current/moma.softwareheritage.org
*******************************************
  File[/etc/gunicorn/instances/swh-storage.cfg] =>
   parameters =>
     content =>
      @@ -41,5 +41,5 @@
       # custom settings
       bind = "unix:/run/gunicorn/swh-storage/gunicorn.sock"
      -workers = 4
      +workers = 16
       worker_class = "sync"
       timeout = 3600
*******************************************
  Gunicorn::Instance[swh-storage] =>
   parameters =>
     settings =>
       workers =>
        - 4
        + 16
*******************************************
*** End octocatalog-diff on moma.softwareheritage.org

---

Migrated from D4725 (view on Phabricator)