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README.textile fixes.

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1 parent 8df6837 commit e8a31c8743247ddf8469ff0ba6bf2e774fdde75d @elia elia committed Nov 13, 2009
Showing with 16 additions and 10 deletions.
  1. +16 −10 README.textile
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@@ -11,11 +11,12 @@ It is a direct extraction from Shopify where the job table is responsible for a
* updating solr, our search server, after product changes
* batch imports
* spam checks
-
+
h2. Setup
-
+
The library evolves around a delayed_jobs table which looks as follows:
+<pre><code>
create_table :delayed_jobs, :force => true do |table|
table.integer :priority, :default => 0 # Allows some jobs to jump to the front of the queue
table.integer :attempts, :default => 0 # Provides for retries, but still fail eventually.
@@ -27,26 +28,29 @@ The library evolves around a delayed_jobs table which looks as follows:
table.string :locked_by # Who is working on this object (if locked)
table.timestamps
end
+</code></pre>
On failure, the job is scheduled again in 5 seconds + N ** 4, where N is the number of retries.
-The default MAX_ATTEMPTS is 25. After this, the job either deleted (default), or left in the database with "failed_at" set.
+The default @MAX_ATTEMPTS@ is @25@. After this, the job either deleted (default), or left in the database with "failed_at" set.
With the default of 25 attempts, the last retry will be 20 days later, with the last interval being almost 100 hours.
-The default MAX_RUN_TIME is 4.hours. If your job takes longer than that, another computer could pick it up. It's up to you to
+The default @MAX_RUN_TIME@ is @4.hours@. If your job takes longer than that, another computer could pick it up. It's up to you to
make sure your job doesn't exceed this time. You should set this to the longest time you think the job could take.
By default, it will delete failed jobs (and it always deletes successful jobs). If you want to keep failed jobs, set
-Delayed::Job.destroy_failed_jobs = false. The failed jobs will be marked with non-null failed_at.
+@Delayed::Job.destroy_failed_jobs = false@. The failed jobs will be marked with non-null failed_at.
Here is an example of changing job parameters in Rails:
+<pre><code>
# config/initializers/delayed_job_config.rb
Delayed::Job.destroy_failed_jobs = false
silence_warnings do
Delayed::Job.const_set("MAX_ATTEMPTS", 3)
Delayed::Job.const_set("MAX_RUN_TIME", 5.minutes)
end
+</code></pre>
Note: If your error messages are long, consider changing last_error field to a :text instead of a :string (255 character limit).
@@ -56,21 +60,23 @@ h2. Usage
Jobs are simple ruby objects with a method called perform. Any object which responds to perform can be stuffed into the jobs table.
Job objects are serialized to yaml so that they can later be resurrected by the job runner.
+<pre><code>
class NewsletterJob < Struct.new(:text, :emails)
def perform
emails.each { |e| NewsletterMailer.deliver_text_to_email(text, e) }
end
end
Delayed::Job.enqueue NewsletterJob.new('lorem ipsum...', Customers.find(:all).collect(&:email))
-
+</code></pre>
+
There is also a second way to get jobs in the queue: send_later.
-
- BatchImporter.new(Shop.find(1)).send_later(:import_massive_csv, massive_csv)
-
+<pre><code>
+ BatchImporter.new(Shop.find(1)).send_later(:import_massive_csv, massive_csv)
+</code></pre>
-This will simply create a Delayed::PerformableMethod job in the jobs table which serializes all the parameters you pass to it. There are some special smarts for active record objects
+This will simply create a @Delayed::PerformableMethod@ job in the jobs table which serializes all the parameters you pass to it. There are some special smarts for active record objects
which are stored as their text representation and loaded from the database fresh when the job is actually run later.

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