Sidekiq strategy to support a granular queue control – limiting, pausing, blocking, querying.
Add this line to your application's Gemfile:
Important note: At this moment,
sidekiq-limit_fetch is incompatible with
- sidekiq pro's
- any other plugin that rewrites fetch strategy of sidekiq.
require 'sidekiq-limit_fetch' if it isn't already. It will not work until then.
Specify limits which you want to place on queues inside sidekiq.yml:
:limits: queue_name1: 5 queue_name2: 10
Or set it dynamically in your code:
Sidekiq::Queue['queue_name1'].limit = 5 Sidekiq::Queue['queue_name2'].limit = 10
In these examples, tasks for the
queue_name1 will be run by at most 5
workers at the same time and the
queue_name2 will have no more than 10
Ability to set limits dynamically allows you to resize worker distribution among queues any time you want.
Limits per process
If you use multiple sidekiq processes then you can specify limits per process:
:process_limits: queue_name: 2
Or set it in your code:
Sidekiq::Queue['queue_name'].process_limit = 2
Busy workers by queue
You can see how many workers currently handling a queue:
Sidekiq::Queue['name'].busy # number of busy workers
You can also pause your queues temporarily. Upon continuing their limits will be preserved.
Sidekiq::Queue['name'].pause # prevents workers from running tasks from this queue Sidekiq::Queue['name'].paused? # => true Sidekiq::Queue['name'].unpause # allows workers to use the queue Sidekiq::Queue['name'].pause_for_ms(1000) # will pause for a second
Blocking queue mode
If you use strict queue ordering (it will be used if you don't specify queue weights) then you can set blocking status for queues. It means if a blocking queue task is executing then no new task from lesser priority queues will be ran. Eg,
:queues: - a - b - c :blocking: - b
In this case when a task for
b queue is ran no new task from
will be started.
You can also enable and disable blocking mode for queues on the fly:
Sidekiq::Queue['name'].block Sidekiq::Queue['name'].blocking? # => true Sidekiq::Queue['name'].unblock
Advanced blocking queues
You can also block on array of queues. It means when any of them is running only queues higher and queues from their blocking group can run. It will be easier to understand with an example:
:queues: - a - b - c - d :blocking: - [b, c]
In this case tasks from
d will be blocked when a task from queue
c is executed.
You can dynamically set exceptions for queue blocking:
You can support dynamic queues (that are not listed in sidekiq.yml but
that have tasks pushed to them (usually with
To use this mode you need to specify a following line in sidekiq.yml:
Dynamic queues will be ran at the lowest priority.
If you use
flushdb, restart the sidekiq process to re-populate the dynamic configuration.