private void ScheduleRecurringJob(BackgroundProcessContext context, IStorageConnection connection,
string recurringJobId, RecurringJobEntity recurringJob, DateTime now)
{
// We always start a transaction, regardless our recurring job was updated or not,
// to prevent from infinite loop, when there's an old processing server (pre-1.7.0)
// in our environment that doesn't know it should modify the score for entries in
// the recurring jobs set.
using (var transaction = connection.CreateWriteTransaction())
{
try
{
// We can't handle recurring job with unsupported versions - there may be additional
// features. we don't know about. We also shouldn't stop the whole scheduler as
// there may be jobs with lower versions. Instead, we'll re-schedule such a job and
// emit a warning message to the log.
if (recurringJob.Version.HasValue && recurringJob.Version > MaxSupportedVersion)
{
throw new NotSupportedException($"Server '{context.ServerId}' can't process recurring job '{recurringJobId}' of version '{recurringJob.Version ?? 1}'. Max supported version of this server is '{MaxSupportedVersion}'.");
}
BackgroundJob backgroundJob = null;
IReadOnlyDictionary <string, string> changedFields;
if (recurringJob.TrySchedule(out var nextExecution, out var error))
{
if (nextExecution.HasValue && nextExecution <= now)
{
backgroundJob = _factory.TriggerRecurringJob(context.Storage, connection, _profiler, recurringJob, now);
if (String.IsNullOrEmpty(backgroundJob?.Id))
{
_logger.Debug($"Recurring job '{recurringJobId}' execution at '{nextExecution}' has been canceled.");
}
}
recurringJob.IsChanged(out changedFields, out nextExecution);
}
else
{
throw new InvalidOperationException("Recurring job can't be scheduled, see inner exception for details.", error);
}
if (backgroundJob != null)
{
_factory.StateMachine.EnqueueBackgroundJob(
context.Storage,
connection,
transaction,
recurringJob,
backgroundJob,
"Triggered by recurring job scheduler",
_profiler);
}
transaction.UpdateRecurringJob(recurringJob, changedFields, nextExecution, _logger);
}
catch (Exception ex)
{
throw new BackgroundJobClientException(ex.Message, ex);
}
// We should commit transaction outside of the internal try/catch block, because these
// exceptions are always due to network issues, and in case of a timeout exception we
// can't determine whether it was actually succeeded or not, and can't perform an
// idempotent retry in this case.
transaction.Commit();
}
}
