Informix - Problem description
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) |