Added some job queue comments

Change-Id: If42b982ac339cc6aaf56ef2ed6c78867b83d2e56

diff --git a/includes/jobqueue/Job.php b/includes/jobqueue/Job.php
index 56fd1c6..334d374 100644 (file)
--- a/includes/jobqueue/Job.php
+++ b/includes/jobqueue/Job.php
@@ -135,7 +135,15 @@ abstract class Job implements IJobSpecification {
        }
 
        /**
-        * @return bool Whether only one of each identical set of jobs should be run
+        * Whether the queue should reject insertion of this job if a duplicate exists
+        *
+        * This can be used to avoid duplicated effort or combined with delayed jobs to
+        * coalesce updates into larger batches. Claimed jobs are never treated as
+        * duplicates of new jobs, and some queues may allow a few duplicates due to
+        * network partitions and fail-over. Thus, additional locking is needed to
+        * enforce mutual exclusion if this is really needed.
+        *
+        * @return bool
         */
        public function ignoreDuplicates() {
                return $this->removeDuplicates;