Ross Boylan wrote: > On Tue, Oct 04, 2005 at 10:14:57PM +0200, Kern Sibbald wrote: > >>On Tuesday 04 October 2005 20:51, Phil Stracchino wrote: >> >>>Ross Boylan wrote: >>> >>>>The description of the priority option for Job says that >>>>"If by chance Bacula treats a lower priority first, then it will run >>>>before your high priority jobs. To avoid this, start any higher >>>>priority a few seconds before the lower ones." >>>> >>>>I don't understand what good priorities do then. If I schedule the >>>>jobs in the sequence I want them to run, that alone should determine >>>>their sequence (at least if I follow the recommendation for one job at >>>>a time). The discussion seems to imply that priority is relevant >>>>both with and without concurrent jobs. >>> >>>I believe the answer is that the prioritizing code doesn't actually work >>>as well as it is intended to. >>> >>>A suggestion here, Kern: Since the Director already "preschedules" >>>upcoming jobs, could it not sort and queue them in order of priority at >>>that time? >> >>I believe that it already does exactly that. It is just that it is *very* >>hard to guarantee something 100% if the times are identical. >> >>If someone wants to invest the time to look at this, and if it is broken, >>submit a patch, great. Otherwise, I stick to my (perhaps poorly worded) >>advice above. >> > > Given jobs scheduled at different times, does priority add anything to > when they are run?
If a higher priority job is running, a lower priority job will not start. "higher priority" means a low value for Priority "lower priority" means a higher value for Priority So, let's say you want your catalog backup to run after all your other jobs have finished. Give the Catalog job a priority of 40 and all your other jobs a priority of 30. What doesn't seem to be guaranteed is that *if* you schedule all your jobs to start at the same time, the catalog backup doesn't get started before the other jobs. What I think bacula does is this: when a job is starting, it looks at the priority of that job and if any jobs are running with a lower value for their priority, it waits until those jobs are done before starting the new job. So, Priority is useful when you want to impose order on a set of jobs, but when the concurrency levels don't allow the control you require. I run 8 jobs daily. They're called * Bankside * Thor * Artemis * Users_and_Depts * Zeus * Zetafax * Cases * BackupCatalog I have two DLT8000 drives, holding 40GiB each uncompressed. Bankside, Users_and_Depts, Zeus and Cases all come off the same server. Zetafax wants to be backed up last, as it needs to wait for SQL Server to dump its databases to disk and then for my script on the server to gzip those backups. The Cases job fills a whole tape by itself. So, I have 4 groups of jobs: Group #1: Bankside, Thor, Artemis, Users_and_Depts and Zeus - backed up to drive #1, first Group #2: Cases - backed up to drive #2, first, and concurrently with group #1 Group #3: Zetafax - backed up to drive #1, after group #1 has finished Group #4: BackupCatalog - backed up to drive #1, after ALL OTHER backups have finished. So, group #1 and group #2 are scheduled to start at the same time with the same priority (I want them to run concurrently). Group #3 is scheduled to start a few minutes after group #1 with the same priority (it will wait on max storage jobs until all the jobs in group #1 have finished) Group #4 has a larger priority value so that it waits until the other jobs have finished before starting. So, after thinking it through, you only need to use the Priority setting to impose execution order on jobs which you can't impose order upon any other way (normally you can do it just by scheduling them a little later, and they'll wait on max storage jobs or max client jobs, etc). -- Russell Howe [EMAIL PROTECTED] ------------------------------------------------------- This SF.Net email is sponsored by: Power Architecture Resource Center: Free content, downloads, discussions, and more. http://solutions.newsforge.com/ibmarch.tmpl _______________________________________________ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
