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Problem IT35284
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Status: Closed |
READAHEAD THREAD MAY NOT RECEIVE WAKEUP CALL RESULTING IN HANG OF OTHER THREADS
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| 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) |
