Daylight savings issue

[Former Member]

Hi Experts,

I have an issue with the daylight savings with my companys CPS.

This spring, when the daylight savings changed, we dicsovered that CPS did not respect this, and we had to shift our running jobs one hour manually.

As far as I know, CPS should be able to take this change into account.

As a cicrumvention we have our frequently running jobs defined to run in 4 hours time windows(which are open or closed depending on the actual time).

Now, as a daylight change will happenb again this autumn, I want to be prepared for this.

Of course my preferred solution would be, that CPS plans its schedule correctly.

Do I have to upgrade my CPS?

Or do I have to change something on the OS of the server on which CPS is running?

Here are my system specifications:

CPS Version: Build:M33.10-45085

Server: AIX

AIX level and especially two concrete filesets are above the vulnerable range for the known issue with DST.

08:14:26 root@chwis232: /home/root

# oslevel -s

6100-07-04-1216

More information:

Anyway the Timezone is specified in POSIX format which caused problems in the past AIX levels. One option was to convert to different format of definition the Timezone (Olson format). It may fix your problem, so please approve the change to Olson format (reboot required).

More information:

http://www-01.ibm.com/support/docview.wss?uid=isg3T1013017&myns=pwraix71&mync=E

Basically we have option 2 of the linked note implemented (what was actually linked in the SAP note you sent me originally)

But IBM still recommends to change the timezone type.

According to SAP Help documentation, CPS uses Olson Timezone tape:

http://help.sap.com/saphelp_nw70ehp1/helpdata/en/68/7052b03a074008b2cccdc186da0b38/frameset.htm

This does not mean that it is necessary that OS has also Olson Timezone type.

I cannot estimate the possible impact, but think that negative impact cannot 100% be excluded.

I am open for suggestions(Do I have to raise an OSS note??)

Regards

Greg

[gmblom · Accepted solution]

Hello,

Can you elaborate more on "CPS did not respect DST"? Did none of your jobs respect it, maybe some?

Note that there have been some issues in this area in the past and since your are on a version that is about 2 years old, you might start to think about upgrading it.

Anyway, to get you prepared, I will explain how CPS handles DST.

The first most important thing about DST is that you have to make sure that your jobs are scheduled in a time zone that have DST. So if you schedule your jobs in GMT, no time shifting will occur anyway. You can check the original time zone of your jobs by hovering over a job and look at the tool tip that will pop up. Be aware, the job times are always displayed in your own (User Settings) time zone (that can be found in the title bar of your browser).

Now two scenarios:

1) Spring (go to summertime (northern hemisphere), time goes from 2:00 to 3:00)

The basis of CPS is that it tries to start all jobs that are scheduled now or in the past. So when the time shifts at 2:00 to 3:00 all jobs that are scheduled to run between 2:00 and 3:00 will all start to run. After this all jobs will pick up their normal schedule again.

2) Autumn (go to wintertime (northern hemisphere), time goes from 3:00 back to 2:00)

Now in the first iteration between 2:00 and 3:00 all jobs will run regularly, and when at 3:00 it becomes 2:00 again, no jobs will be scheduled during the second iteration and when it is 3:00 for the second time all jobs will run again according to their schedule.

Now here is that catch, almost all jobs will pick up their original schedule again. The only jobs that have difficulty are the ones that schedule slower then every hour, but quicker then every day (so every 2 hours, every 4 hours etc). The workaround for these is to use a submit frame that uses the start time field, this start time will be the offset from which the every x hours are calculated.

Regards Gerben

[Former Member · Accepted solution]

Hello Gerben,

Thank you for your detailed answer.

To your first question: Only some jobs did not respect the DST change. Others did.

Therefore your input to have all jobs in a timezone is very valuable.

I have now given every job my timezone(which is Europe/Zurich) and that one should respect the DST(at last thats what google told me).

Of course I will track the change when it will happen - then I will update the results here within.

Regards

Greg

[former_member753256]

What will happen to the dependent batch jobs ?

[former_member72868]

Hi Greg,

Also check the following KBAs about DST and CPS:

http://service.sap.com/sap/support/notes/1694167

http://service.sap.com/sap/support/notes/1696980

Regards,

David Glynn

[Former Member]

Hi David,

Thanks for your input!

@all: I will update this Forum Post, when the change took place.