Signal 11 thrown by SAP

[Former Member]

Hi All,

Recently I faced one issue regarding the signal 11 by SAP.

Though it is an error of OS level , but could we get the actual reason for it . Like why OS is giving the signal 11 , or how we can do a step by step analysis of the issues.

Please provide me any SAP recommended note for it.

[former_member182657 · Accepted solution]

Hi,

Like why OS is giving the signal 11 ,

For signal 11 you could check with system event viewer as well as developer trace dev_w0 .This issue could be resolved with the help of kernel upgrade or patch.

Regards,

[Former Member · Accepted solution]

There is a core dump generated by SAP in work directly on that time . Would it be helpful to analyze the root cause?

Dev_W* and dev_disp are attached below.

[Reagan]

You should change the ulimit of the sidadm user and restart the SAP system.

I would set the ulimit for the sidadm user to unlimited except for the coredump

[Former Member]

Hi Benjamin,

I don't think ulimit change is at all required. As this is already recommended by SAP for AIX environment.

[divyanshu_srivastava3]

As said before - check 1972803 - SAP on AIX: Recommendations - RB  has a valid point that is mentioned in this note.

Regards,

[former_member182657]

Hi,

As per shared logs by you getting

DPTraceStatus: Child killed with signal error 11

For the issue suggest you to refer SAP Note  1606116 - Work process restarts after signal 11

which is also suggesting to patch the kernel,as same i recommended earlier to you.

If possible share dev_w0 log file for analysis.

Regards,

[Former Member]

I completely understood what you say , but my question is If this is an program error then where it is documented.

I have the kernel patch 721_EXT ,PL-331 . Is there any sap note where it is documented ? or any KBA?

And moreover when you will get signal 11 and you will go with Kernel upgrade ? is this recommended?

Will share the developer whole logs soon.

[former_member182657]

If this is an program error then where it is documented.

And moreover when you will get signal 11 and you will go with Kernel upgrade ? is this recommended?

No it's not recommended all the time,it would be best to share dev_w0 & dev_disp first for suggesting exact solutions for the thread.

[Former Member]

Hi All,

I got an SAP Note , 1658260 which clearly says that the Kernel patch are having some bug. So they have solved it on PL=402 , Maybe these needs kernel upgrade.

So before that I think this should be consult with SAP .

Thanks Guys .

[divyanshu_srivastava3]

You said you are on

OS -AIX
Kernel -721_EXT,PL-331

From where in that SAP note you have found that there are problems in your current version ?

Is that an assumption you made ?

Anyways, good luck.

Regards,

[Former Member]

Hi Divyanshu,

The SAP Note tell that the problem is solved on patch 402. But We are on patch level 300 . So it is possible that we are in bug .

And if you see on market place - after PL -40 released but the SAP Note is not mentioned , but on 402 the error is mentioned and SAP Note updated.

That is why I have written .

[divyanshu_srivastava3]

Ok.. good then.. As I have faced this problem in AIX before - and have seen this more on 32 bits than 64 bits system, at was either kernel or memory config issue.

You haven't read my replies perhaps.. which were broader in context to signal 11

But you know, your kernel has a higher level + already have the solution for error that was described in that note you refereed and 402 doesn't means it was your kernel release - that is what I can see.

Raise it with SAP and see what they says.

Regards,

[divyanshu_srivastava3]

And yes do check these notes which I shared before, that have a lot that you can do.

A slight tuning can be very effective,

1497677 - AIX: Apparent memory leak in EM

1972803 - SAP on AIX: Recommendations

973227 - AIX: Virtual Memory Management Tuning Recommendations

Regards,

[divyanshu_srivastava3]

If you are getting singal 11 which you can see in SM21, I believe there must a dump in ST22 too.. some thing was either running in dialog or background, that can also help you, for eg a background job - where you might have to segregate data,

Also, what is your OS ? AIX, Linux, Unix etx ?

Also your kernel release too is important in this case.

For eg, depending on what you see in Sm21, Wp logs and St22, and on your OS, kernel, system.

You can refer following notes.

350167 - Process killed by Signal 11 or Signal 10 - for sunOS

1606116 - Work process restarts after signal 11 - kernel issue.

386605 - SAP Memory Management for Linux (32-bit) - search signal 11 in this note.

Please check above are and then consolidate and share to help you further.

Regards,

[Former Member]

Please find the logs as attached.

=========================

[divyanshu_srivastava3]

What was running on your system when the signal 11 was issued ?

What is your SAP system release  and AIX version?

Can upload the full trace file for the first WP which was terminated with signal 11 and exit code 225 ?

Also, in your system, on that work process, what was running ? you can get this from SM21 and ST22.

I think there was some kind of parallel processing going on.

Have a look at below KBAs

1497677 - AIX: Apparent memory leak in EM

1972803 - SAP on AIX: Recommendations

973227 - AIX: Virtual Memory Management Tuning Recommendations

[former_member182657]

Hi,

You could refer SAP Note   350167 - Process killed by Signal 11 or Signal 10

Regards,

[Former Member]

Hi Gaurav,

OS -AIX

Kernel -721_EXT,PL-331

Kernel is upgraded few days back. Don't think this is a program error . But Somehow it may caused due to some program deleted and segment was not released by OS . And after that OS unable to assign the address to WPs properly and which shutdown the processes and send signal 11 .

I don't know . But I don't feel that Kernel upgrade is really necessary here.

[former_member230159]

Hi Biswajit,

Did you receive system_core_dump that terminated with signal 11 ?

In this case you need to check the dump to understand what caused the dump.

Also check related work process to understand the reason behind dump.

If possible share dump and wp trace file here.

Regards,

Manjunath