Hello

How could we know exactly how many Cores Informix is using on a Power IBM  Server (AIX) ?

Not the Sys view but the informix view ( -g glo helps ?)

thanks in advance

Yes, the onstat -g glo report will tell you the PIDs of all of the oninit processes. You can use other OS tools to see what cores they are running on. I the ONCONFIG file, if you VPCLASS parameter contains the "aff" options that will tell you if the oninits are affined to specific cores. On other systems than AIX I would run top, add the processor number to the displayed columns, then filter for "oninit" to see what cores the oninit processes are running on, but "top" isn't supported on AIX I believe, and topas is not as good and I don't think that you can get the processor number from topas. I'm sure there are AIX tools to get that, but I cannot remember what they are. It's been a while since I was live on an AIX system for long.

Art

Hello

How could we know exactly how many Cores Informix is using on a Power IBM  Server (AIX) ?

Not the Sys view but the informix view ( -g glo helps ?)

thanks in advance

Thanks Art, 
no, affinity is not used
i prefer to continue with g glo, so the part of output to use is the "total" part, it is expressed on seconds
let s say, 200000 seconds, but i don"t know to what compare this value to know the percentrage of CPUs used on the system

Yes, the onstat -g glo report will tell you the PIDs of all of the oninit processes. You can use other OS tools to see what cores they are running on. I the ONCONFIG file, if you VPCLASS parameter contains the "aff" options that will tell you if the oninits are affined to specific cores. On other systems than AIX I would run top, add the processor number to the displayed columns, then filter for "oninit" to see what cores the oninit processes are running on, but "top" isn't supported on AIX I believe, and topas is not as good and I don't think that you can get the processor number from topas. I'm sure there are AIX tools to get that, but I cannot remember what they are. It's been a while since I was live on an AIX system for long.

Art

Hello

How could we know exactly how many Cores Informix is using on a Power IBM  Server (AIX) ?

Not the Sys view but the informix view ( -g glo helps ?)

thanks in advance

Hello

How could we know exactly how many Cores Informix is using on a Power IBM  Server (AIX) ?

Not the Sys view but the informix view ( -g glo helps ?)

thanks in advance

Interesting question, because of "cores".

Cores are different from "logical processors" visible to the operating system (AIX).

With SMT-N, generally, Informix will have access to N x Cores logical processors, and, at peak load, will utilize 100% of X processors where "X" is the number of Informix CPUVPs. If there are more logical processors than configured CPUVPs.

Basically, if the LPAR has 1 core in SMT-8, Informix is configured with 8 CPUVPs, and all of processors are 100% busy - Informix is using (approximately) 1 core (AIX overhead is not significant, unless there is substantial amount of I/O and/or network traffic)

However, if there are significantly more logical processors than Informix CPUVPs, then core utilization will depend on AIX parameter "vpm_throughput_mode". If set to "0" - scheduling preference for active processes (CPUVPs) will be on the primary core threads, so with, say, 8 extremely busy VPs will actually use very close to 8 cores (if those are available). With different setting of "vpm_throughput_mode" - AIX may schedule busy VPs to the threads on the same core before going to another one. Performance, clearly, will be quite different.

Yet another level of complexity is the fact that LPAR can have logical processors that can only use fraction of the core computing resources. But (shared LPAR) sometimes can "borrow" processing capacity from other LPARs that share same core(s)

Nevertheless, because AIX is the only O/S (I know of) with very precise CPU time accounting, there is a very simple way to figure out how many cores worth of processing power Informix actually used during specific time interval:

onstat -z ; sleep 60 ; onstat -p

Add usercpu + syscpu and divide by 60 - that will give effective number of cores utilized by Informix during this minute.  The usercpu  + syscpu are the same as in onstat -g glo (which even gives total) - so it can be used instead of "onstat -p"

Hello

How could we know exactly how many Cores Informix is using on a Power IBM  Server (AIX) ?

Not the Sys view but the informix view ( -g glo helps ?)

thanks in advance

Thanks Vladimir,
so, i have a machine with 7 Cores,
SMT4,
14 CPU VPCLASS  (i think it s recommended to put 2 VP per Core with SMT4)
and (onstat -z ; sleep 60 ; onstat -p) difference is 5, is it using 5 trom the 7 Cores or 5 CPU VPCLASS ?
thanks

Interesting question, because of "cores".

Cores are different from "logical processors" visible to the operating system (AIX).

With SMT-N, generally, Informix will have access to N x Cores logical processors, and, at peak load, will utilize 100% of X processors where "X" is the number of Informix CPUVPs. If there are more logical processors than configured CPUVPs.

Basically, if the LPAR has 1 core in SMT-8, Informix is configured with 8 CPUVPs, and all of processors are 100% busy - Informix is using (approximately) 1 core (AIX overhead is not significant, unless there is substantial amount of I/O and/or network traffic)

However, if there are significantly more logical processors than Informix CPUVPs, then core utilization will depend on AIX parameter "vpm_throughput_mode". If set to "0" - scheduling preference for active processes (CPUVPs) will be on the primary core threads, so with, say, 8 extremely busy VPs will actually use very close to 8 cores (if those are available). With different setting of "vpm_throughput_mode" - AIX may schedule busy VPs to the threads on the same core before going to another one. Performance, clearly, will be quite different.

Yet another level of complexity is the fact that LPAR can have logical processors that can only use fraction of the core computing resources. But (shared LPAR) sometimes can "borrow" processing capacity from other LPARs that share same core(s)

Nevertheless, because AIX is the only O/S (I know of) with very precise CPU time accounting, there is a very simple way to figure out how many cores worth of processing power Informix actually used during specific time interval:

onstat -z ; sleep 60 ; onstat -p

Add usercpu + syscpu and divide by 60 - that will give effective number of cores utilized by Informix during this minute.  The usercpu  + syscpu are the same as in onstat -g glo (which even gives total) - so it can be used instead of "onstat -p"

Hello

How could we know exactly how many Cores Informix is using on a Power IBM  Server (AIX) ?

Not the Sys view but the informix view ( -g glo helps ?)

thanks in advance

Thanks Vladimir,
so, i have a machine with 7 Cores,
SMT4,
14 CPU VPCLASS  (i think it s recommended to put 2 VP per Core with SMT4)
and (onstat -z ; sleep 60 ; onstat -p) difference is 5, is it using 5 trom the 7 Cores or 5 CPU VPCLASS ?
thanks

Interesting question, because of "cores".

Cores are different from "logical processors" visible to the operating system (AIX).

With SMT-N, generally, Informix will have access to N x Cores logical processors, and, at peak load, will utilize 100% of X processors where "X" is the number of Informix CPUVPs. If there are more logical processors than configured CPUVPs.

Basically, if the LPAR has 1 core in SMT-8, Informix is configured with 8 CPUVPs, and all of processors are 100% busy - Informix is using (approximately) 1 core (AIX overhead is not significant, unless there is substantial amount of I/O and/or network traffic)

However, if there are significantly more logical processors than Informix CPUVPs, then core utilization will depend on AIX parameter "vpm_throughput_mode". If set to "0" - scheduling preference for active processes (CPUVPs) will be on the primary core threads, so with, say, 8 extremely busy VPs will actually use very close to 8 cores (if those are available). With different setting of "vpm_throughput_mode" - AIX may schedule busy VPs to the threads on the same core before going to another one. Performance, clearly, will be quite different.

Yet another level of complexity is the fact that LPAR can have logical processors that can only use fraction of the core computing resources. But (shared LPAR) sometimes can "borrow" processing capacity from other LPARs that share same core(s)

Nevertheless, because AIX is the only O/S (I know of) with very precise CPU time accounting, there is a very simple way to figure out how many cores worth of processing power Informix actually used during specific time interval:

onstat -z ; sleep 60 ; onstat -p

Add usercpu + syscpu and divide by 60 - that will give effective number of cores utilized by Informix during this minute.  The usercpu  + syscpu are the same as in onstat -g glo (which even gives total) - so it can be used instead of "onstat -p"

Hello

How could we know exactly how many Cores Informix is using on a Power IBM  Server (AIX) ?

Not the Sys view but the informix view ( -g glo helps ?)

thanks in advance

Thanks Vladimir,
so, i have a machine with 7 Cores,
SMT4,
14 CPU VPCLASS  (i think it s recommended to put 2 VP per Core with SMT4)
and (onstat -z ; sleep 60 ; onstat -p) difference is 5, is it using 5 trom the 7 Cores or 5 CPU VPCLASS ?
thanks

Interesting question, because of "cores".

Cores are different from "logical processors" visible to the operating system (AIX).

With SMT-N, generally, Informix will have access to N x Cores logical processors, and, at peak load, will utilize 100% of X processors where "X" is the number of Informix CPUVPs. If there are more logical processors than configured CPUVPs.

Basically, if the LPAR has 1 core in SMT-8, Informix is configured with 8 CPUVPs, and all of processors are 100% busy - Informix is using (approximately) 1 core (AIX overhead is not significant, unless there is substantial amount of I/O and/or network traffic)

However, if there are significantly more logical processors than Informix CPUVPs, then core utilization will depend on AIX parameter "vpm_throughput_mode". If set to "0" - scheduling preference for active processes (CPUVPs) will be on the primary core threads, so with, say, 8 extremely busy VPs will actually use very close to 8 cores (if those are available). With different setting of "vpm_throughput_mode" - AIX may schedule busy VPs to the threads on the same core before going to another one. Performance, clearly, will be quite different.

Yet another level of complexity is the fact that LPAR can have logical processors that can only use fraction of the core computing resources. But (shared LPAR) sometimes can "borrow" processing capacity from other LPARs that share same core(s)

Nevertheless, because AIX is the only O/S (I know of) with very precise CPU time accounting, there is a very simple way to figure out how many cores worth of processing power Informix actually used during specific time interval:

onstat -z ; sleep 60 ; onstat -p

Add usercpu + syscpu and divide by 60 - that will give effective number of cores utilized by Informix during this minute.  The usercpu  + syscpu are the same as in onstat -g glo (which even gives total) - so it can be used instead of "onstat -p"

Hello

How could we know exactly how many Cores Informix is using on a Power IBM  Server (AIX) ?

Not the Sys view but the informix view ( -g glo helps ?)

thanks in advance