[BUG] Error while removing app from folder causing crash of CMOD frequently

[rmazurki]

Hi,

We have CMOD on Linux Redhat:
Version:                      10.1.0.11
Operating System:             Linux
Operating System Version:     #1 SMP Wed Jun 15 08:55:08 UTC 2022.3.10.0-1160.71.1.el7.x86_64
Database:                     DB2
Database Version:             11.01.0406

PMR for this was rejected because we have unsupported version 10.1 - we cannot upgrade to 10.5 because we have some relations to old CMOD on mainframe.

Short description of this bug:
App group has 2 or more apps. One app has ALLIAS empty - standard for first application.
Folder contain this app group with all applications included.
Action to generate CMOD crash: Remove from folder application with non empty alias.
Later CMOD will crash again for every try of use this folder.

Longer description at end of this post.

This is just for Your information.
If someone can register this problem to IBM then please do that.

Regards
Rafal

CMOD breakdown 2022-08-23

Procedure to recreate problem:
App group: rafal_test
1.   Create first application – to create first application you don’t have to have field marked in AppGroup as “Application ID field”, so I created new application rafal_test_def
2.   Create second application – to do that You have create field marked in AppGroup as “Application ID field”- so:
a.    I added field “cmodappid”, and I added mapping “PDF/PDF”
b.   Then You can add second application “rafal_test_PDF” with Identifier “PDF”
3.   Create folder “rafal_test” for “rafal_test” app group – by default this folder will contain all applications.
4.   Now we have a setup ready to recreate problem – we have two applications
a.   One without ALIAS
b.   Second with ALIAS = “PDF”
5.   To recreate error we have to update our “rafal_test” folder and remove application having ALIAS = “PDF”. Result will be  - crash of CMOD library server
Now every time You will open “rafal_test” folder (does not matter how) CMOD library server will crash again.
Some info about crash from kernel ring buffer (dmesg | grep arssockd) :
[1922646.654469] arssockd[22471]: segfault at 0 ip 0000000000a7611c sp 00007f85cb3f6388 error 4 in arssockd[400000+bc3000]
[1922909.368816] arssockd[24071]: segfault at 0 ip 0000000000a7611c sp 00007f0b5cfed388 error 4 in arssockd[400000+bc3000]
[1923183.589816] arssockd[25014]: segfault at 0 ip 0000000000a7611c sp 00007effd3bf7388 error 4 in arssockd[400000+bc3000]
Today I know how to fix this issue using manual delete of records from CMOD tables:
1.   Check Your AppGroup id:
select * from ARSAG where NAME = 'rafal_test'
rafal_test      13401

2.   You have to delete records from ARSAG2FOL table having AID <> 0 – I guess this operation is restoring situation before removing application having ALIAS = “PDF”

select * from ARSAG2FOL where AGID=13401
delete from ARSAG2FOL where AGID=13401 and AID <> 0;

[rmazurki]

Hi again,

Does anyone has some procedure to assign ALIAS to application without alias?

[jsquizz]

Trying to understand this.

So when you add applications to an existing app group - by creating a new field and defining it as the application Identifier - with type PDF , you're getting a segmentation fault?

[rmazurki]

new app group
two new applications - first without alias, second with alias
new folder containing this app group - byt default it contains both applications.

CMOD will crash when remove application with alias from folder. And it will crash at every access to this folder later.

[jsquizz]

Since you're out of support, I suggest you just do a new application group with a field named something like- report name

Then do-

database value 1, <AG Description..I usually do like - PDF>
database value 2, <AG Description..I usually do like - XLS>

Then, APP1-PDF mapped to AG, and APP1-XLS mapped to AG. That's how I've always done it.

Might be a pain on the folks who are sending, but the only other option would be to probably extend your support contract with IBM for 10.1, or upgrade to 10.5

Or, a single app group for each app

Or, extend your support contract for 10.1

Or, goto 10.5

[rmazurki]

On my previous post I just give procedure to recreate problem with new CMOD objects.

Real situation I had on production with already defined objects and a lot of data loaded to these objects.
On production I have many applications with this problematic AG. To recreate problem only 2 apps is enough.
So, what i did on production was - add new application to AG and then remove it from folder.

So, my question is - how to fix the data to have possibility to remove application from folder without crash.
I believe it is possible to do it with adding alias to first application without alias.
It is not possible to do such thing from CMOD admin tool AFAIK. Or maybe I am wrong?
If I am not wrong then I am looking for a fix using db values manipulation.

[rmazurki]

Hi,

Just FYI - newest version 10.5.0.5 still has this issue.