It's possible for onstat -z to report a bad mutex and hang the
server...
When the problem occurs, you will see an assertion like this:
18:10:01 Assert Warning: Bad mutex encountered
18:10:01 Who: Session(858, informix@u363, 0,
700000fb4b79d50)
Thread(1051, onmode_mon, 700000fb4b47a28, 1)
File: mt_info.c Line: 1306
18:10:01 Results: Couldn't reset all the spin locks
18:10:01 Action: Please notify IBM Informix Technical
Support.
18:10:01 Raw hex dump of stack located in
/crash/af.8037119.rawstk
18:10:01 Stack for thread: 1051 onmode_mon
base: 0x0700000fb6e21000
len: 69632
pc: 0x00000001000948b0
tos: 0x0700000fb6e2fda0
state: running
vp: 1
(oninit)afstack
(oninit)afhandler
(oninit)afwarn_interface
(oninit)dospinlock
(oninit)zero_profile
(oninit)onmode_monitor
(oninit)th_init_initgls
(oninit)startup
Just because this assertion occurs, that does not mean the hang
will occur.
When the hang occurs, you will see a thread spinning, constantly
running in mt_init_mutex with a stack something like:
state: running
vp: 1
(oninit)poll
(oninit)mt_spin_lock_wait
(oninit)mt_init_mutex
(oninit)ptalloc
(oninit)ptbld
(oninit)ptbuild
(oninit)rspnbuild_sz
(oninit)sqispnbuild
(oninit)bldpartn
(oninit)bldtmpfile
(oninit)filltemp
(oninit)scan_open
(oninit)IPRA.$materialize_viewtmp
(oninit)IPRA.$materialize_viewtmp
(oninit)IPRA.$materialize_viewtmp
(oninit)materialize_viewtmp
(oninit)prepselect
(oninit)open_cursor
(oninit)sql_open
(oninit)sq_open
(oninit)sqmain
(oninit)listen_verify
And the onmode_mon thread will be ready to run with a stack
comparable to:
state: ready
vp: 1
(oninit)yield_processor_mvp
(oninit)mt_yield
(oninit)mt_exec
(oninit)invoke_alarmf
(oninit)afhandler
(oninit)afwarn_interface
(oninit)dospinlock
(oninit)zero_profile
(oninit)onmode_monitor
(oninit)th_init_initgls
(oninit)startup
In this case, the thread that was running was holding a mutex
and there is a user in the waitlist
waiting for a very long time:
12507 700000fb3c1c6b8 dbs_partn_6 89185644 0
89185652 3742
89185673 3731
522 3368
4553222 3013
89110462 903
89086555 608
89086494 91 |
