Technical Blog Post
Abstract
Unexpected DB2LUW hang while using Vintella Authentication Services plug-in
Body
There are few Technote and Document out there on this already.
But, wanted to share this as some customers still faced this issue lately.
The symptom is reported as sudden hang in Db2 database. Nothing progressing.
CPU, memory and I/O were abnormally idle in the box.
That is an indication that nothing really running and stuck some where.
No locking or latching.
A quick running of "db2pd -stack all" will dump the db2 thread stack files under DIAGPATH directory.
Just a quick review of some of the stacks or, grepping the files with function name "vas_db2_plugin_auth_user"
might show the problem quickly.
The stacks will have following kinds of functions at the top :
0x09000000007CC738 _global_lock_common + 0x4B8
0x09000000007F1024 _atfork_prepare + 0x64
0x0900000000116F20 __fork + 0x40
0x09000000047DD440 vas_db2_plugin_auth_user + 0x440
0x09000000047DFE30 vas_db2_plugin_check_password + 0x24C
0x090000000E096DA8 secValidatePasswordPlugin__FPc
0x090000000E09709C sqlexValidatePassword__FPciT1N
0x090000000E0977A4 sqlexSlsSystemAuthenticate__FP
0x090000000E098C0C sqlexSlsServerAuthenticate__FP
0x090000000E099770 sqlexEngAuthenticate__FP14db2U
This is due to usage of VAS plugin.
Please refer :
and,
http://rc.quest.com/topics/db2_sys-auth/
Please do the needful following those technote/document.
The stacks might vary depending on the situations. But, there should a "vas" and/or "plugin" signature in some of the top functions.
UID
ibm11139872