|
Problem IT34509
|
Status: Closed |
REDUCED PERFORMANCE POSSIBLE IN DR ENVIRONMENTS DUE TO CONTENTION ON DRBT_LOCK MUTEX
|
| product: |
INFORMIX SERVER / 5725A3900 / C10 - IDS 12.10 |
| Problem description: |
Secondary servers having high levels of activity may experience
short periods of delay when sqlexec or log replay threads
perform a commit operation. Using the onstat command to collect
stack information for these threads an example is:
yield_processor_mvp
mt_lock_wait
mt_lock_helper
dr_ixrcommit
rscommit
sqiscommit
comwork
sql_nfetch
sq_nfetch
sqmain
The functions below rscommit are not relevant to this issue and
may vary according to the type of operation.
Running the command "onstat -g wmx" may also show one or more
threads waiting for the drbt_lock mutex. The wait times are of
very short duration so this may only be seen infrequently.
A primary server in an environment with only an HDR secondary
server may also show similar information. |
| Problem Summary: |
****************************************************************
* USERS AFFECTED: *
* Users of Informix Server prior to 12.10.xC15 and 14.10.xC5. *
****************************************************************
* PROBLEM DESCRIPTION: *
* Secondary servers having high levels of activity may *
* experience *
* short periods of delay when sqlexec or log replay threads *
* perform a commit operation. Using the onstat command to *
* collect *
* stack information for these threads an example is: *
* *
* yield_processor_mvp *
* mt_lock_wait *
* mt_lock_helper *
* dr_ixrcommit *
* rscommit *
* sqiscommit *
* comwork *
* sql_nfetch *
* sq_nfetch *
* sqmain *
* *
* The functions below rscommit are not relevant to this issue *
* and *
* may vary according to the type of operation. *
* *
* Running the command "onstat -g wmx" may also show one or *
* more *
* threads waiting for the drbt_lock mutex. The wait times are *
* of *
* very short duration so this may only be seen infrequently. *
* *
* A primary server in an environment with only an HDR *
* secondary *
* server may also show similar information. *
****************************************************************
* RECOMMENDATION: *
* Upgrade to Informix Server 12.10.xC15 (when available) or *
* 14.10.xC5. *
**************************************************************** |
| Local Fix: |
In an HDR-only environment setting the onconfig parameter
LOG_INDEX_BUILDS to 1 will avoid this problem on the primary
server. Note that enabling this parameter may lead to increased
usage of logical log space. |
| Solution |
|
| Workaround |
****************************************************************
* USERS AFFECTED: *
* Users of Informix Server prior to 12.10.xC15 and 14.10.xC5. *
****************************************************************
* PROBLEM DESCRIPTION: *
* Secondary servers having high levels of activity may *
* experience *
* short periods of delay when sqlexec or log replay threads *
* perform a commit operation. Using the onstat command to *
* collect *
* stack information for these threads an example is: *
* *
* yield_processor_mvp *
* mt_lock_wait *
* mt_lock_helper *
* dr_ixrcommit *
* rscommit *
* sqiscommit *
* comwork *
* sql_nfetch *
* sq_nfetch *
* sqmain *
* *
* The functions below rscommit are not relevant to this issue *
* and *
* may vary according to the type of operation. *
* *
* Running the command "onstat -g wmx" may also show one or *
* more *
* threads waiting for the drbt_lock mutex. The wait times are *
* of *
* very short duration so this may only be seen infrequently. *
* *
* A primary server in an environment with only an HDR *
* secondary *
* server may also show similar information. *
****************************************************************
* RECOMMENDATION: *
* Upgrade to Informix Server 12.10.xC15 (when available) or *
* 14.10.xC5. *
**************************************************************** |
| Comment |
Fixed in Informix Server 12.10.xC15 and 14.10.xC5. |
| Timestamps |
Date - problem reported :
Date - problem closed :
Date - last modified :
| 13.10.2020
22.01.2021
22.01.2021 |
| Problem solved at the following versions (IBM BugInfos) |
|
| Problem solved according to the fixlist(s) of the following version(s) |
