/// <summary>
/// Exponentially backoff the next run time of a job after every failure (Non-Terminal) upto a defined MAX.
/// Currently, only one time jobs are exponentially backed off, and recurring jobs are just scheduled for next occurence.
/// </summary>
/// <param name="scheduler">
/// Instance of the Scheduler
/// </param>
/// <param name="jobDetails">
/// Scheduled Job Details.
/// </param>
/// <returns>
/// Async Task Wrapper
/// </returns>
public static async Task ExponentiallyBackoffAsync(this IScheduler scheduler, ScheduledJobDetails jobDetails, CommerceLog log)
{
// this branch should not happen once we schedule the job once.
if (jobDetails != null && jobDetails.Recurrence != null)
{
// if job is scheduled to run only once
if (jobDetails.Recurrence.Count == 1)
{
// initialize retry count if it does not exist
if (jobDetails.Payload == null)
{
jobDetails.Payload = new Dictionary <string, string>();
jobDetails.Payload["RetryCount"] = "0";
}
else if (!jobDetails.Payload.ContainsKey("RetryCount"))
{
jobDetails.Payload["RetryCount"] = "0";
}
int retryCount;
if (!int.TryParse(jobDetails.Payload["RetryCount"], out retryCount))
{
retryCount = 0;
}
//Important: Since the job is a run once job, so recurrence for the next retry is solely
// dependent on the retry interval. Past recurrence is immaterial.
jobDetails.Recurrence = new Recurrence()
{
Frequency = RecurrenceFrequency.Second,
Count = 1,
Interval = GetWaitTimeInSeconds(retryCount)
};
log.Verbose("Job Id {0} has been retried {1} times, back off to try the next time after {2} seconds",
jobDetails.JobId,
retryCount,
jobDetails.Recurrence.Interval);
// increment retry count in payload
jobDetails.Payload["RetryCount"] = (retryCount + 1).ToString(CultureInfo.InvariantCulture);
// schedule it to run later
await scheduler.UpdateJobAsync(jobDetails).ConfigureAwait(false);
}
else // recurring job
{
// just mark current iteration as done. We will try again next time
await scheduler.CompleteJobIterationAsync(jobDetails).ConfigureAwait(false);
}
}
else
{
log.Warning("After first run of job, job or recurrence should not be null.");
await Task.Factory.StartNew(() => { }).ConfigureAwait(false);
}
}
