Error while loading a Cube in BW - "Waiting for Semaphore"

[Former Member]

Hello Experts:

I seem to be having a frequent problem while doing a Delta load from BW (3.5) cube to exactly similar cube in BI 7.0.

The load is done daily via a Process Chain. Before doing the Delta load, I also have a step to DELET Index from the

cube in BI. The Delta loads have been successful but frequently they take about 7 or 8 hours to load. The number of

records are not many 80,000 to 140,000 records range. There have been successful loads for similar range withing

7 or 8 minutes. However, when it gets hung up it takes 7 or 8 hours.

Looks like it is a Lock happening in 3.5 BW system. Tcode SM12 shows that it is locked and then in T. Code SM66, it

shows that it is hun for resources..... The message inicated is "Waiting for Semaphore". After about 7 hours, the load

automatically happens.

This is causing issues becuase the upward data loads don't happen and Users can not access the data until late afternoon

for their planning in BPC.

Is there a way this error or Waiting for Semaphore be avoided or time is reduced....? How can I achieve this? Any

fne tuning tricks anyone can suggest please......!!

Thanks a lot in advance.

[Former Member · Accepted solution]

Hi,

While facing the issue, could you also check SM50 tcode?

It should show the corresponding work process as waiting for semaphore along with the semaphore number it is waiting for.

In your case it should also display the Locked Semaphore number and if it is being held by another work process.

Also check the corresponding work process developer traces from sm50.

Regards,

Srikishan

[Former Member]

Hello,

As Srikishan mentioned, please try to confirm semaphore number from sm50 and then try to search for OSS notes for that semaphore number, for e.g. Note 1286629 - Wait situation for semaphore 35

Thanks

[Former Member]

Thanks to both of you.... ppreciate the feedback. I guess, I will have to wait for the situation to arise again as today's delta went normally. I will see if this happens again. I am not sure whether the Semaphore number is same as the "Work Process Number" in SM66 (which was 3 in my case) or is it the Process ID (which is 22872082 in my case).

If I go to SM50, I shoudl find either the Process ID then.

Would I be searching for the OSS notes corresponding to Process ID (in this case 22872082...? or would it for sempahore number (if it is different .... as I mentioned 3 in my case..?

Could you please clarify which is Semaphore number and if it is same as the process ID I am talking about so that I can search for the right OSS notes.

Also, finding all this will only tell me why it hung.... but is there a way we can make it kick off and not get stuck or I have to wait it out until the resources get released.....? Which in my case then would stil be a wait for 6/7 hours!!

Apreciate your feedback.

Best..... Lee