Informix - Problem description
Problem IT35039 | Status: Closed |
EXCEPTION CAUGHT DURING QUERY OF SYSSCBLST TABLE MAY LEAVE MUTEXLOCKED WITH POTENTIAL FOR DEADLOCK | |
product: | |
INFORMIX SERVER / 5725A3900 / C10 - IDS 12.10 | |
Problem description: | |
The processing of a query for the pseudo table sysscblst in the sysmaster database may result in an exception which interrupts the query processing. The clean up of the query processing may leave a mutex named scbthd in a locked state which can later lead to a deadlock situation. The deadlock can be seen in the output of the "onstat -g wmx" command as in this example: Mutexes with waiters: mid addr name holder lkcnt waiter waittime 19 443a3838 session 19099537 0 20 1729 19099536 1729 718290922 21044fca0 scbthd 19099536 0 19094197 1729 19099537 1729 The thread with id 19099537 is the holder of the session mutex and is waiting for access to the scbthd mutex. The thread holding that mutex, with id 19099536, is waiting for the session mutex and the result is deadlock. A typical stack for the thread holding the session mutex may be: yield_processor_mvp mt_lock_wait mt_lock_helper mt_prscblst pstread pst_rsread rsread fmread readseq_single gettupl scan_next hjoin_next hjoin_next sort_open prepselect open_cursor sql_open sq_open sqmain An example stack for the thread holding the scbthd mutex may be: yield_processor_mvp mt_lock_wait mt_lock_helper destroy_session sq_exit sqmain Other stacks for this thread may be possible. Queries using the sysmaster view syssessions are also susceptible. | |
Problem Summary: | |
**************************************************************** * USERS AFFECTED: * * Users of Informix Server prior to 12.10.xC15 and 14.10.xC6. * **************************************************************** * PROBLEM DESCRIPTION: * * See Error Description * **************************************************************** * RECOMMENDATION: * * Upgrade to Informix Server 12.10.xC15 (when available) or * * 14.10.xC6 (when available). * **************************************************************** | |
Local Fix: | |
Solution | |
Workaround | |
**************************************************************** * USERS AFFECTED: * * Users of Informix Server prior to 12.10.xC15 and 14.10.xC6. * **************************************************************** * PROBLEM DESCRIPTION: * * See Error Description * **************************************************************** * RECOMMENDATION: * * Upgrade to Informix Server 12.10.xC15 (when available) or * * 14.10.xC6 (when available). * **************************************************************** | |
Comment | |
Fixed in Informix Server 12.10.xC15 and 14.10.xC6. | |
Timestamps | |
Date - problem reported : Date - problem closed : Date - last modified : | 24.11.2020 10.12.2020 10.12.2020 |
Problem solved at the following versions (IBM BugInfos) | |
Problem solved according to the fixlist(s) of the following version(s) |