Informix - Problem description
Problem IT32308 | Status: Closed |
INTERRUPTING A HANGING (SUSPENDED) 'CDR SYNC' WOULD LEAVE THE GLOBAL CATALOG LOCKED AND CAUSE LOCK ERRORS TO OTHER CDR COMMANDS | |
product: | |
INFORMIX SERVER / 5725A3900 / C10 - IDS 12.10 | |
Problem description: | |
A 'cdr sync' scan internally can go into suspended mode, even right from the beginning, if the the send queue is in danger of or already spooling. You'd see a CDRScn_ thread in status "cond wait ERScanCond" in 'onstat -g ath', e.g. 16926 95ce6928 44ffe6c8 1 cond wait ERScanCond 8cpu CDRScn_131091 When interrupting the sync in such state, e.g. by hitting Ctrl-C on the command line that initiated the sync, the scan(s) would get flagged for abortion, the associated shadow replicate would be removed, through two secondary threads 'asyncReplDelete' and 'GCReq', with the later holding a bunch of locks on various syscdr tables, yet this whole clean-up process could not complete without the scanners first disappearing - which they'd not do as they're suspended. These would be more threads potentially visible in such state: 16927 95ce66a0 45000a48 1 join wait 16928 1cpu asyncReplDelete 16928 961bc028 44ffd508 1 cond wait ERRsncCond 9cpu GCReq 16929 95ce6418 44ffcc28 1 cond wait CDR_GC 8cpu GCReq 16931 958350d0 45000168 1 yield lockwait 10cpu CDRFlushQue Any further attempt to, e.g., start newly same or another sync would run on -244/-154 for those syscdr locks held. | |
Problem Summary: | |
**************************************************************** * USERS AFFECTED: * * Users of Informix Server prior to 12.10.xC15 and 14.10.xC4. * **************************************************************** * PROBLEM DESCRIPTION: * * See Error Description * **************************************************************** * RECOMMENDATION: * * Upgrade to Informix Server 12.10.xC15 (when available) or * * 14.10.xC4. * **************************************************************** | |
Local Fix: | |
As a workaround could be attempted to briefly/temporarily increase CDR_QUEUEMEM by factor 2 or so which would allow such scanner to exit suspended state, terminate itself and let all the clean-up complete. | |
Solution | |
Workaround | |
**************************************************************** * USERS AFFECTED: * * Users of Informix Server prior to 12.10.xC15 and 14.10.xC4. * **************************************************************** * PROBLEM DESCRIPTION: * * See Error Description * **************************************************************** * RECOMMENDATION: * * Upgrade to Informix Server 12.10.xC15 (when available) or * * 14.10.xC4. * **************************************************************** | |
Comment | |
Fixed in Informix Server 12.10.xC15 and 14.10.xC4. | |
Timestamps | |
Date - problem reported : Date - problem closed : Date - last modified : | 25.03.2020 14.12.2020 14.12.2020 |
Problem solved at the following versions (IBM BugInfos) | |
Problem solved according to the fixlist(s) of the following version(s) |