Informix - Problem description
Problem IT35284 | Status: Closed |
READAHEAD THREAD MAY NOT RECEIVE WAKEUP CALL RESULTING IN HANG OF OTHER THREADS | |
product: | |
INFORMIX SERVER / 5725A3900 / E10 - | |
Problem description: | |
A ReadAhead thread will enter a wait state when it finds no requests to be serviced and will then be woken up by another thread when such a request is made. A timing window exists where the wakeup request may not be serviced as intended and the readahead request is not serviced immediately. If there are no further readahead requests made then the problem request will remain in a pending state which may cause its requesting thread to hang at a later point in time. In one scenario the thread named "bld_logrecs" may hang at the end of logical recovery with a stack of the form: (oninit)yield_processor_mvp (oninit)mt_yield (oninit)ra_terminate_req (oninit)ra_free_req (oninit)bld_logrecs (oninit)startup This will cause the Informix server to remain in the Fast Recovery state and a restart may be required. This issue may be observed in versions including the fix for IT32067, first released in 14.10.xC5. | |
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: | |
If stuck in the Fast recovery state then issuing the command "onbar -b -l" should help to resolve the problem. If not then the Informix server should be restarted whereupon it may successfully complete Fast Recovery. Due to the nature of the timing window the server may become stuck again in which case temporarily reducing the number of CPU VPs to 1 followed by a further restart should allow it to complete Fast Recovery. | |
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 : | 16.12.2020 11.05.2021 11.05.2021 |
Problem solved at the following versions (IBM BugInfos) | |
Problem solved according to the fixlist(s) of the following version(s) |