Rails Sidekiq: Job executes on the wrong service
2 min readDec 13, 2021
It might be relates to our Sidekiq config, Redis URL.
We shouldn’t use duplicate URLs if we are running multiple Sidekiq services on the same Redis service. We need to configure Redis URL with a different number for each service
Solution
Let’s say we have Rails Service A and Rails Service B.
Rails Service A, we set 0 to the url
# config/initializers/sidekiq.rbSidekiq.configure_server do |config|
config.redis = { url: 'redis://localhost:6379/0' }
end
Sidekiq.configure_client do |config|
config.redis = { url: 'redis://localhost:6379/0' }
end
Rails Service B, we set 1 to the url
# config/initializers/sidekiq.rbSidekiq.configure_server do |config|
config.redis = { url: 'redis://localhost:6379/1' }
end
Sidekiq.configure_client do |config|
config.redis = { url: 'redis://localhost:6379/1' }
end
Which number we should use?
The default range of numbers is 0–15 depending on the database’s index setting in redis.conf
To check range of numbers
$ cat /etc/redis/redis.conf | grep databases -C 5 Result:
# Set the number of databases. The default database is DB 0, you can select
# a different one on a per-connection basis using SELECT <dbid> where
# dbid is a number between 0 and 'databases'-1databases 16
databases 16 means we can set redis url to 0–15
- redis://localhost:6379/0
- redis://localhost:6379/1
- redis://localhost:6379/2
- redis://localhost:6379/3
- …
- redis://localhost:6379/15
So, pick one and make sure it isn’t used by another Rails service 😉
