Retry Policies

If an error occurs while executing a background task, Jobby can run it again. If the task is recurrent, it will be run again according to its schedule. If the task is non-recurrent, it will be run according to the configured retry policy.

Basic Configuration

A retry policy is a RetryPolicy object that contains:

• The maximum number of attempts to execute a task
• The pause values in seconds between retry attempts

var retryPolicy = new RetryPolicy
{
    // Maximum total number of task execution attempts
    // A value of 3 means that if the task fails
    // on the first attempt,
    // two additional retry attempts will be made
    MaxCount = 3,

    // Pauses between execution attempts when tasks fail
    // First retry will occur after one second,
    // second retry after two seconds
    IntervalsSeconds = [1, 2]
}

// You don't need to specify all values in IntervalSeconds
// For example, if we want to retry a task 10 times 
// every 10 minutes, the following approach works:
retryPolicy = new RetryPolicy
{
    MaxCount = 11,
    IntervalsSeconds = [600]
}

The retry policy can be global (applied to all tasks) or unique to a specific task type. This is configured during library setup:

jobbyBuilder
    // the policy from the defaultPolicy object will be applied by default
    .UseDefaultRetryPolicy(defaultPolicy)
    // but a different policy will be applied for SendEmailCommand tasks
    .UseRetryPolicyForJob<SendEmailCommand>(specialRetryPolicy);

Jitter

Jobby can add an additional random delay (so-called Jitter) to the fixed pause values between attempts.

To enable this feature, you need to populate the JitterMaxValuesMs list in the RetryPolicy object, which contains the maximum additional delay values in milliseconds for pauses between specific attempts.

The example below shows a retry policy that, after the first attempt, adds a pause of 1 second plus a random value up to 100 ms, and after the second attempt, 2 seconds plus a random value up to 200 ms.

retryPolicy = new RetryPolicy
{
    MaxCount = 3,
    IntervalsSeconds = [1, 2],

    // Values for additional random delays
    // in milliseconds
    JitterMaxValuesMs = [100, 200]
}