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- Introduction
- Usage
- Requirements
- Locks
- Conflict Strategy
- Debugging
- Testing
- Configuration
- Communication
- Contributing
- Contributors
This gem adds unique constraints to sidekiq jobs. The uniqueness is achieved by creating a set of keys in redis based off of queue
, class
, args
(in the sidekiq job hash).
By default, only one lock for a given hash can be acquired. What happens when a lock can't be acquired is governed by a chosen Conflict Strategy strategy. Unless a conflict strategy is chosen (?)
This is the documentation for the main
branch. You can find the documentation for each release by navigating to its tag.
Here are links to some of the old versions
Add this line to your application's Gemfile:
gem 'sidekiq-unique-jobs'
And then execute:
bundle
Before v7, the middleware was configured automatically. Since some people reported issues with other gems (see Other Sidekiq Gems) it was decided to give full control over to the user.
NOTE if you want to use the reaper you also need to configure the server middleware.
The following shows how to modify your config/initializers/sidekiq.rb
file to use the middleware. Here is a full example.
require "sidekiq-unique-jobs"
Sidekiq.configure_server do |config|
config.redis = { url: ENV["REDIS_URL"], driver: :hiredis }
config.client_middleware do |chain|
chain.add SidekiqUniqueJobs::Middleware::Client
end
config.server_middleware do |chain|
chain.add SidekiqUniqueJobs::Middleware::Server
end
SidekiqUniqueJobs::Server.configure(config)
end
Sidekiq.configure_client do |config|
config.redis = { url: ENV["REDIS_URL"], driver: :hiredis }
config.client_middleware do |chain|
chain.add SidekiqUniqueJobs::Middleware::Client
end
end
The lock type most likely to be is :until_executed
. This type of lock creates a lock from when UntilExecutedWorker.perform_async
is called until right after UntilExecutedWorker.new.perform
has been called.
# frozen_string_literal: true
class UntilExecutedWorker
include Sidekiq::Worker
sidekiq_options lock: :until_executed
def perform
logger.info("cowboy")
sleep(1) # hardcore processing
logger.info("beebop")
end
end
You can read more about the worker configuration in Worker Configuration below.
- Sidekiq
>= 5.0
(>= 5.2
recommended) - Ruby:
- MRI
>= 2.5
(>= 2.6
recommended) - JRuby
>= 9.0
(>= 9.2
recommended) - Truffleruby
- MRI
- Redis Server
>= 3.2
(>= 5.0
recommended) - [ActiveJob officially not supported][48]
- [redis-namespace officially not supported][49]
See [Sidekiq requirements][24] for detailed requirements of Sidekiq itself (be sure to check the right sidekiq version).
A lock is created when UntilExecuting.perform_async
is called. Then it is either unlocked when lock_ttl
is hit or before Sidekiq calls the perform
method on your worker.
class UntilExecuting
include Sidekiq::Workers
sidekiq_options lock: :until_executing
def perform(id)
# Do work
end
end
NOTE this is probably not so good for jobs that shouldn't be running simultaneously (aka slow jobs).
The reason this type of lock exists is to fix the following problem: sidekiq/issues/3471
A lock is created when UntilExecuted.perform_async
is called. Then it is either unlocked when lock_ttl
is hit or when Sidekiq has called the perform
method on your worker.
class UntilExecuted
include Sidekiq::Workers
sidekiq_options lock: :until_executed
def perform(id)
# Do work
end
end
This lock behaves identically to the Until Executed except for one thing. This job won't be unlocked until the expiration is hit. For jobs that need to run only once per day, this would be the perfect lock. This way, we can't create more jobs until one day after this job was first pushed.
class UntilExpired
include Sidekiq::Workers
sidekiq_options lock: :until_expired, lock_ttl: 1.day
def perform
# Do work
end
end
This lock is a combination of two locks (:until_executing
and :while_executing
). Please see the configuration for Until Executing and While Executing
class UntilAndWhileExecutingWorker
include Sidekiq::Workers
sidekiq_options lock: :until_and_while_executing,
lock_timeout: 2,
on_conflict: {
client: :log,
server: :raise
}
def perform(id)
# Do work
end
end
These locks are put on a queue without any type of locking mechanism, the locking doesn't happen until Sidekiq pops the job from the queue and starts processing it.
class WhileExecutingWorker
include Sidekiq::Workers
sidekiq_options lock: :while_executing,
lock_timeout: 2,
on_conflict: {
server: :raise
}
def perform(id)
# Do work
end
end
NOTE Unless a conflict strategy of :raise
is specified, if lock fails, the job will be dropped without notice. When told to raise, the job will be put back and retried. It would also be possible to use :reschedule
with this lock.
NOTE Unless this job is configured with a lock_timeout: nil
or lock_timeout: > 0
then all jobs that are attempted to be executed will just be dropped without waiting.
There is an example of this to try it out in the myapp
application. Run foreman start
in the root of the directory and open the url: localhost:5000/work/duplicate_while_executing
.
In the console you should see something like:
0:32:24 worker.1 | 2017-04-23T08:32:24.955Z 84404 TID-ougq4thko WhileExecutingWorker JID-400ec51c9523f41cd4a35058 INFO: start
10:32:24 worker.1 | 2017-04-23T08:32:24.956Z 84404 TID-ougq8csew WhileExecutingWorker JID-8d6d9168368eedaed7f75763 INFO: start
10:32:24 worker.1 | 2017-04-23T08:32:24.957Z 84404 TID-ougq8crt8 WhileExecutingWorker JID-affcd079094c9b26e8b9ba60 INFO: start
10:32:24 worker.1 | 2017-04-23T08:32:24.959Z 84404 TID-ougq8cs8s WhileExecutingWorker JID-9e197460c067b22eb1b5d07f INFO: start
10:32:24 worker.1 | 2017-04-23T08:32:24.959Z 84404 TID-ougq4thko WhileExecutingWorker JID-400ec51c9523f41cd4a35058 WhileExecutingWorker INFO: perform(1, 2)
10:32:34 worker.1 | 2017-04-23T08:32:34.964Z 84404 TID-ougq4thko WhileExecutingWorker JID-400ec51c9523f41cd4a35058 INFO: done: 10.009 sec
10:32:34 worker.1 | 2017-04-23T08:32:34.965Z 84404 TID-ougq8csew WhileExecutingWorker JID-8d6d9168368eedaed7f75763 WhileExecutingWorker INFO: perform(1, 2)
10:32:44 worker.1 | 2017-04-23T08:32:44.965Z 84404 TID-ougq8crt8 WhileExecutingWorker JID-affcd079094c9b26e8b9ba60 WhileExecutingWorker INFO: perform(1, 2)
10:32:44 worker.1 | 2017-04-23T08:32:44.965Z 84404 TID-ougq8csew WhileExecutingWorker JID-8d6d9168368eedaed7f75763 INFO: done: 20.009 sec
10:32:54 worker.1 | 2017-04-23T08:32:54.970Z 84404 TID-ougq8cs8s WhileExecutingWorker JID-9e197460c067b22eb1b5d07f WhileExecutingWorker INFO: perform(1, 2)
10:32:54 worker.1 | 2017-04-23T08:32:54.969Z 84404 TID-ougq8crt8 WhileExecutingWorker JID-affcd079094c9b26e8b9ba60 INFO: done: 30.012 sec
10:33:04 worker.1 | 2017-04-23T08:33:04.973Z 84404 TID-ougq8cs8s WhileExecutingWorker JID-9e197460c067b22eb1b5d07f INFO: done: 40.014 sec
You may need to define some custom lock. You can define it in one project folder:
# lib/locks/my_custom_lock.rb
module Locks
class MyCustomLock < SidekiqUniqueJobs::Lock::BaseLock
def execute
# Do something ...
end
end
end
You can refer on all the locks defined in lib/sidekiq_unique_jobs/lock/*.rb
.
In order to make it available, you should call in your project startup:
(For rails application config/initializers/sidekiq_unique_jobs.rb or other projects, wherever you prefer)
SidekiqUniqueJobs.configure do |config|
config.add_lock :my_custom_lock, Locks::MyCustomLock
end
And then you can use it in the jobs definition:
sidekiq_options lock: :my_custom_lock, on_conflict: :log
Please not that if you try to override a default lock, an ArgumentError
will be raised.
Decides how we handle conflict. We can either reject
the job to the dead queue or reschedule
it. Both are useful for jobs that absolutely need to run and have been configured to use the lock WhileExecuting
that is used only by the sidekiq server process.
Furthermore, log
can be be used with the lock UntilExecuted
and UntilExpired
. Now we write a log entry saying the job could not be pushed because it is a duplicate of another job with the same arguments.
It is possible for locks to have different conflict strategy for the client and server. This is useful for :until_and_while_executing
.
sidekiq_options lock: :until_and_while_executing,
on_conflict: { client: :log, server: :reject }
sidekiq_options on_conflict: :log
This strategy is intended to be used with UntilExecuted
and UntilExpired
. It will log a line that this job is a duplicate of another.
sidekiq_options on_conflict: :raise
This strategy is intended to be used with WhileExecuting
. Basically it will allow us to let the server process crash with a specific error message and be retried without messing up the Sidekiq stats.
sidekiq_options on_conflict: :reject
This strategy is intended to be used with WhileExecuting
and will push the job to the dead queue on conflict.
sidekiq_options on_conflict: :replace
This strategy is intended to be used with client locks like UntilExecuted
.
It will delete any existing job for these arguments from retry, schedule and
queue and retry the lock again.
This is slightly dangerous and should probably only be used for jobs that are always scheduled in the future. Currently only attempting to retry one time.
sidekiq_options on_conflict: :reschedule
This strategy is intended to be used with WhileExecuting
and will delay the job to be tried again in 5 seconds (this delay can be configured via sidekiq_options schedule_in: {seconds}
). This will mess up the sidekiq stats but will prevent exceptions from being logged and confuse your sysadmins.
You may need to define some custom strategy. You can define it in one project folder:
# lib/strategies/my_custom_strategy.rb
module Strategies
class MyCustomStrategy < SidekiqUniqueJobs::OnConflict::Strategy
def call
# Do something ...
end
end
end
You can refer to all the strategies defined in lib/sidekiq_unique_jobs/on_conflict
.
In order to make it available, you should call in your project startup:
(For rails application config/initializers/sidekiq_unique_jobs.rb for other projects, wherever you prefer)
SidekiqUniqueJobs.configure do |config|
config.add_strategy :my_custom_strategy, Strategies::MyCustomStrategy
end
And then you can use it in the jobs definition:
sidekiq_options lock: :while_executing, on_conflict: :my_custom_strategy
Please not that if you try to override a default lock, an ArgumentError
will be raised.
For sidekiq versions < 5.1 a sidekiq_retries_exhausted
block is required per worker class. This is deprecated in Sidekiq 6.0
class MyWorker
sidekiq_retries_exhausted do |msg, _ex|
digest = msg['lock_digest']
SidekiqUniqueJobs::Digests.new.delete_by_digest(digest) if digest
end
end
Starting in v5.1, Sidekiq can also fire a global callback when a job dies: In version 7, this is handled automatically for you. You don't need to add a death handler, if you configure v7 like in Add the middleware you don't have to worry about the below.
Sidekiq.configure_server do |config|
config.death_handlers << ->(job, _ex) do
digest = job['lock_digest']
SidekiqUniqueJobs::Digests.new.delete_by_digest(digest) if digest
end
end
There are several ways of removing keys that are stuck. The prefered way is by using the unique extension to Sidekiq::Web
. The old console and command line versions still work but might be deprecated in the future. It is better to search for the digest itself and delete the keys matching that digest.
To use the web extension you need to require it in your routes.
#app/config/routes.rb
require 'sidekiq_unique_jobs/web'
mount Sidekiq::Web, at: '/sidekiq'
There is no need to require 'sidekiq/web'
since sidekiq_unique_jobs/web
already does this.
To filter/search for keys we can use the wildcard *
. If we have a unique digest 'uniquejobs:9e9b5ce5d423d3ea470977004b50ff84
we can search for it by enter *ff84
and it should return all digests that end with ff84
.
To be able to gather some insights on what is going on inside this gem. I provide a reflection API that can be used.
To setup reflections for logging or metrics, use the following API:
def extract_log_from_job(message, job_hash)
worker = job_hash['class']
args = job_hash['args']
lock_args = job_hash['lock_args']
queue = job_hash['queue']
{
message: message,
worker: worker,
args: args,
lock_args: lock_args,
queue: queue
}
end
SidekiqUniqueJobs.reflect do |on|
on.lock_failed do |job_hash|
message = extract_log_from_job('Lock Failed', job_hash)
Sidekiq.logger.warn(message)
end
end
This is called when you have configured a custom callback for when a lock has been released.
Not in use yet but will be used deep into the stack to provide a means to catch and report errors inside the gem.
When the sidekiq processor picks the job of the queue for certain jobs but your job raised an error to the middleware. This will be the reflection. It is probably nothing to worry about. When your worker raises an error, we need to handle some edge cases for until and while executing.
If we can't achieve a lock, this will be the reflection. It most likely is nothing to worry about. We just couldn't retrieve a lock in a timely fashion.
The biggest reason for this reflection would be to gather metrics on which workers fail the most at the locking step for example.
For when a lock has been successful. Again, mostly useful for metrics I suppose.
For when the reschedule strategy failed to reschedule the job.
For when a job was successfully rescheduled
This is also mostly useful for reporting/metrics purposes. What this reflection does is signal that the job was configured to wait (lock_timeout
was configured), but we couldn't retrieve a lock even though we waited for some time.
This means that the server middleware could not unlock your job and the lock is kept (potentially preventing subsequent jobs from being pushed or processed).
Also mostly useful for reporting purposes. The job was successfully unlocked.
The reason this happens is that the server couldn't find a valid sidekiq worker class. Most likely, that worker isn't intended to be processed by this sidekiq server instance.
Since v7 it is possible to perform some simple validation against your workers sidekiq_options
. What it does is scan for some issues that are known to cause problems in production.
Let's take a bad worker:
#app/workers/bad_worker.rb
class BadWorker
sidekiq_options lock: :while_executing, on_conflict: :replace
end
#spec/workers/bad_worker_spec.rb
require "sidekiq_unique_jobs/testing"
RSpec.describe BadWorker do
specify { expect(described_class).to have_valid_sidekiq_options }
end
This gives us a helpful error message for a wrongly configured worker:
Expected BadWorker to have valid sidekiq options but found the following problems:
on_server_conflict: :replace is incompatible with the server process
If you are not using RSpec (a lot of people prefer minitest or test unit) you can do something like:
assert_raise(InvalidWorker){ SidekiqUniqueJobs.validate_worker!(BadWorker.get_sidekiq_options) }
This has been probably the most confusing part of this gem. People get really confused with how unreliable the unique jobs have been. I there for decided to do what Mike is doing for sidekiq enterprise. Read the section about unique jobs: Enterprise unique jobs(?)
SidekiqUniqueJobs.configure do |config|
config.enabled = !Rails.env.test?
config.logger_enabled = !Rails.env.test?
end
If you truly wanted to test the sidekiq client push you could do something like below. Note that it will only work for the jobs that lock when the client pushes the job to redis (UntilExecuted, UntilAndWhileExecuting and UntilExpired).
require "sidekiq_unique_jobs/testing"
RSpec.describe Workers::CoolOne do
before do
SidekiqUniqueJobs.config.enabled = false
end
# ... your tests that don't test uniqueness
context 'when Sidekiq::Testing.disabled?' do
before do
Sidekiq::Testing.disable!
Sidekiq.redis(&:flushdb)
end
after do
Sidekiq.redis(&:flushdb)
end
it 'prevents duplicate jobs from being scheduled' do
SidekiqUniqueJobs.use_config(enabled: true) do
expect(described_class.perform_in(3600, 1)).not_to eq(nil)
expect(described_class.perform_async(1)).to eq(nil)
end
end
end
end
It is recommended to leave the uniqueness testing to the gem maintainers. If you care about how the gem is integration tested have a look at the following specs:
- spec/sidekiq_unique_jobs/lock/until_and_while_executing_spec.rb
- spec/sidekiq_unique_jobs/lock/until_executed_spec.rb
- spec/sidekiq_unique_jobs/lock/until_expired_spec.rb
- spec/sidekiq_unique_jobs/lock/while_executing_reject_spec.rb
- spec/sidekiq_unique_jobs/lock/while_executing_spec.rb
It was reported in #536 that the order of the Sidekiq middleware needs to be as follows.
Sidekiq.client_middleware do |chain|
chain.add Apartment::Sidekiq::Middleware::Client
chain.add SidekiqUniqueJobs::Middleware::Client
end
Sidekiq.server_middleware do |chain|
chain.add Apartment::Sidekiq::Middleware::Server
chain.add SidekiqUniqueJobs::Middleware::Server
end
The reason being that this gem needs to be configured AFTER the apartment gem or the apartment will not be able to be considered for uniqueness
It was reported in #235 that the order of the Sidekiq middleware needs to be as follows.
For a working setup check the following file.
Sidekiq.client_middleware do |chain|
chain.add Sidekiq::GlobalId::ClientMiddleware
chain.add SidekiqUniqueJobs::Middleware::Client
end
Sidekiq.server_middleware do |chain|
chain.add Sidekiq::GlobalId::ServerMiddleware
chain.add SidekiqUniqueJobs::Middleware::Server
end
The reason for this is that the global id needs to be set before the unique jobs middleware runs. Otherwise that won't be available for uniqueness.
It was reported in #564 that the order of the middleware needs to be as follows.
# Thanks to @ArturT for the correction
Sidekiq.configure_server do |config|
config.client_middleware do |chain|
chain.add SidekiqUniqueJobs::Middleware::Client
chain.add Sidekiq::Status::ClientMiddleware, expiration: 30.minutes
end
config.server_middleware do |chain|
chain.add Sidekiq::Status::ServerMiddleware, expiration: 30.minutes
chain.add SidekiqUniqueJobs::Middleware::Server
end
SidekiqUniqueJobs::Server.configure(config)
end
Sidekiq.configure_client do |config|
config.client_middleware do |chain|
chain.add SidekiqUniqueJobs::Middleware::Client
chain.add Sidekiq::Status::ClientMiddleware, expiration: 30.minutes
end
end
The reason for this is that if a job is duplicated it shouldn't end up with the status middleware at all. Status is just a monitor so to prevent clashes, leftovers and ensure cleanup. The status middleware should run after uniqueness on client and before on server. This will lead to less surprises.
The gem supports a few different configuration options that might be of interest if you run into some weird issues.
Configure SidekiqUniqueJobs in an initializer or the sidekiq initializer on application startup.
SidekiqUniqueJobs.configure do |config|
config.logger = Sidekiq.logger # default, change at your own discretion
config.logger_enabled = true # default, disable for test environments
config.debug_lua = false # Turn on when debugging
config.lock_info = false # Turn on when debugging
config.lock_ttl = 600 # Expire locks after 10 minutes
config.lock_timeout = nil # turn off lock timeout
config.max_history = 0 # Turn on when debugging
config.reaper = :ruby # :ruby, :lua or :none/nil
config.reaper_count = 1000 # Stop reaping after this many keys
config.reaper_interval = 600 # Reap orphans every 10 minutes
config.reaper_timeout = 150 # Timeout reaper after 2.5 minutes
config.digest_algorithm = :modern # Timeout reaper after 2.5 minutes
end
For backwards compatibility this one is set to :legacy
by the default. If you happen to run into issues with FIPS being enabled on your redis server you might want to set this to :modern
.
See: #848 for explanation
SidekiqUniqueJobs.configure do |config|
config.digest_algorithm = :modern # Timeout reaper after 2.5 minutes
end
SidekiqUniqueJobs.config.debug_lua #=> false
Turning on debug_lua will allow the lua scripts to output debug information about what the lua scripts do. It will log all redis commands that are executed and also some helpful messages about what is going on inside the lua script.
SidekiqUniqueJobs.config.lock_timeout #=> 0
Set a global lock_timeout (in seconds) to use for all jobs that don't otherwise specify a lock_timeout.
Lock timeout decides how long to wait for acquiring the lock. A value of nil means to wait indefinitely for a lock resource to become available.
SidekiqUniqueJobs.config.lock_ttl #=> nil
Set a global lock_ttl (in seconds) to use for all jobs that don't otherwise specify a lock_ttl.
Lock TTL decides how long to wait at most before considering a lock to be expired and making it possible to reuse that lock.
SidekiqUniqueJobs.config.enabled #=> true
Globally turn the locking mechanism on or off.
SidekiqUniqueJobs.config.logger #=> #<Sidekiq::Logger:0x00007fdc1f96d180>
By default this gem piggybacks on the Sidekiq logger. It is not recommended to change this as the gem uses some features in the Sidekiq logger and you might run into problems. If you need a different logger and you do run into problems then get in touch and we'll see what we can do about it.
SidekiqUniqueJobs.config.max_history #=> 1_000
The max_history setting can be used to tweak the number of changelogs generated. It can also be completely turned off if performance suffers or if you are just not interested in using the changelog.
This is a log that can be accessed by a lock to see what happened for that lock. Any items after the configured max_history
will be automatically deleted as new items are added.
SidekiqUniqueJobs.config.reaper #=> :ruby
If using the orphans cleanup process it is critical to be aware of the following. The :ruby
job is much slower but the :lua
job locks redis while executing. While doing intense processing it is best to avoid locking redis with a lua script. There for the batch size (controlled by the reaper_count
setting) needs to be reduced.
In my benchmarks deleting 1000 orphaned locks with lua performs around 65% faster than deleting 1000 keys in ruby.
On the other hand if I increase it to 10 000 orphaned locks per cleanup (reaper_count: 10_0000
) then redis starts throwing:
BUSY Redis is busy running a script. You can only call SCRIPT KILL or SHUTDOWN NOSAVE. (RedisClient::CommandError)
If you want to disable the reaper set it to :none
, nil
or false
. Actually, any value that isn't :ruby
or :lua
will disable the reaping.
SidekiqUniqueJobs.config.reaper = :none
SidekiqUniqueJobs.config.reaper = nil
SidekiqUniqueJobs.config.reaper = false
SidekiqUniqueJobs.config.reaper_count #=> 1_000
The reaper_count setting configures how many orphans at a time will be cleaned up by the orphan cleanup job. This might have to be tweaked depending on which orphan job is running.
SidekiqUniqueJobs.config.reaper_interval #=> 600
The number of seconds between reaping.
SidekiqUniqueJobs.config.reaper_timeout #=> 10
The number of seconds to wait for the reaper to finish before raising a TimeoutError. This is done to ensure that the next time we reap isn't getting stuck due to the previous process already running.
SidekiqUniqueJobs.config.lock_prefix #=> "uniquejobs"
Use if you want a different key prefix for the keys in redis.
SidekiqUniqueJobs.config.lock_info #=> false
Using lock info will create an additional key for the lock with a json object containing information about the lock. This will be presented in the web interface and might help track down why some jobs are getting stuck.
Lock info gathers information about a specific lock. It collects things like which lock_args
where used to compute the lock_digest
that is used for maintaining uniqueness.
sidekiq_options lock_info: false # this is the default, set to true to turn on
Use if you want a different key prefix for the keys in redis.
sidekiq_options lock_prefix: "uniquejobs" # this is the default value
Lock TTL decides how long to wait at most before considering a lock to be expired and making it possible to reuse that lock.
Starting from v7
the expiration will take place when the job is pushed to the queue.
sidekiq_options lock_ttl: nil # default - don't expire keys
sidekiq_options lock_ttl: 20.days.to_i # expire this lock in 20 days
This is the timeout (how long to wait) when creating the lock. By default we don't use a timeout so we won't wait for the lock to be created. If you want it is possible to set this like below.
sidekiq_options lock_timeout: 0 # default - don't wait at all
sidekiq_options lock_timeout: 5 # wait 5 seconds
sidekiq_options lock_timeout: nil # lock indefinitely, this process won't continue until it gets a lock. VERY DANGEROUS!!
This configuration option is slightly misleading. It doesn't disregard the queue on other jobs. Just on itself, this means that a worker that might schedule jobs into multiple queues will be able to have uniqueness enforced on all queues it is pushed to.
This is mainly intended for Worker.set(queue: :another).perform_async
.
class Worker
include Sidekiq::Worker
sidekiq_options unique_across_queues: true, queue: 'default'
def perform(args); end
end
Now if you push override the queue with Worker.set(queue: 'another').perform_async(1)
it will still be considered unique when compared to Worker.perform_async(1)
(that was actually pushed to the queue default
).
This configuration option is slightly misleading. It doesn't disregard the worker class on other jobs. Just on itself, this means that the worker class won't be used for generating the unique digest. The only way this option really makes sense is when you want to have uniqueness between two different worker classes.
class WorkerOne
include Sidekiq::Worker
sidekiq_options unique_across_workers: true, queue: 'default'
def perform(args); end
end
class WorkerTwo
include Sidekiq::Worker
sidekiq_options unique_across_workers: true, queue: 'default'
def perform(args); end
end
WorkerOne.perform_async(1)
# => 'the jobs unique id'
WorkerTwo.perform_async(1)
# => nil because WorkerOne just stole the lock
Sometimes it is desired to have a finer control over which arguments are used in determining uniqueness of the job, and others may be transient. For this use-case, you need to define either a lock_args
method, or a ruby proc.
NOTE: The lock_args method need to return an array of values to use for uniqueness check.
NOTE: The arguments passed to the proc or the method is always an array. If your method takes a single array as argument the value of args will be [[...]]
.
The method or the proc can return a modified version of args without the transient arguments included, as shown below:
class UniqueJobWithFilterMethod
include Sidekiq::Worker
sidekiq_options lock: :until_and_while_executing,
lock_args_method: :lock_args # this is default and will be used if such a method is defined
def self.lock_args(args)
[ args[0], args[2][:type] ]
end
...
end
class UniqueJobWithFilterProc
include Sidekiq::Worker
sidekiq_options lock: :until_executed,
lock_args_method: ->(args) { [ args.first ] }
...
end
It is possible to ensure different types of unique args based on context. I can't vouch for the below example but see #203 for the discussion.
class UniqueJobWithFilterMethod
include Sidekiq::Worker
sidekiq_options lock: :until_and_while_executing, lock_args_method: :lock_args
def self.lock_args(args)
if Sidekiq::ProcessSet.new.size > 1
# sidekiq runtime; uniqueness for the object (first arg)
args.first
else
# queuing from the app; uniqueness for all params
args
end
end
end
If you need to perform any additional work after the lock has been released you can provide an #after_unlock
instance method. The method will be called when the lock has been unlocked. Most times this means after yield but there are two exceptions to that.
Exception 1: UntilExecuting unlocks and uses callback before yielding. Exception 2: UntilExpired expires eventually, no after_unlock hook is called.
NOTE: It is also possible to write this code as a class method.
class UniqueJobWithFilterMethod
include Sidekiq::Worker
sidekiq_options lock: :while_executing,
def self.after_unlock
# block has yielded and lock is released
end
def after_unlock
# block has yielded and lock is released
end
...
end.
There is a for praise or scorn. This would be a good place to have lengthy discuss or brilliant suggestions or simply just nudge me if I forget about anything.
- Fork it
- Create your feature branch (
git checkout -b my-new-feature
) - Commit your changes (
git commit -am 'Add some feature'
) - Push to the branch (
git push origin my-new-feature
) - Create new Pull Request
You can find a list of contributors over on Contributors