Information request about scalability and concurrency settings

[vvayngart1]

ruby-2.7.6
rails 6.1.7.6
Sidekiq (6.5.12)
redis_version:4.0.9
Sidekiq-pro (5.5.5)

Good afternoon

I'm looking for information on the following topics:

• How can I configure a particular number of Sidekiq processes to run?
• Is the :concurrency: setting referring to a number of threads/processes or a number of processes?
• If :concurrency: setting refers to a number of threads per process, is it correct that they can use the Singleton object's instance? To clarify, if I want to establish and reuse only 1 TCP/IP connection without opening 1/thread, can I do this?
• Any information or links to credible sources on general guidelines for below items is greatly appreciated:
  • General principles for setting up in concert with each other:
    • Sidekiq concurrency (processes/threads)
    • Rails concurrency
    • CPU settings

Thanks in advance

[mperham]

How can I configure a particular number of Sidekiq processes to run?

With Sidekiq Enterprise you'd use sidekiqswarm and the SIDEKIQ_COUNT variable. You can use other tools to run multiple processes but we don't provide documentation for any particular tool.

Concurrency is the thread count within each Sidekiq process. Yes, they can use Singleton.

You can use RAILS_MAX_THREADS to control all the knobs for Sidekiq and Rails concurrency in one setting.

RAILS_MAX_THREADS=5 SIDEKIQ_COUNT=8 bundle exec sidekiqswarm

will get you 8 processes with 5 threads or a total job concurrency of 40.