Number of online engines

louissickler

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Dec 11, 2009, 4:55:10 PM12/11/09

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Hi Everyone,

Just a quick question that I did not find the answer to with
a google search. I have some new DBMS hosts which are
going to be running Sybase 15.0.3 ESD 2 and they have 4 dual
core CPU's. Should I configure 4 online engines or 8 online
engines. I assumed 8 but the dataserver recognizes that it
only has 4 CPU's and wont allow me to change it to 8 unless
I set SRV_CPUCOUNT. Anyway what is the best way to run the
server given it is only a DBMS server and I want to allocate
all CPU's to the database server. Thanks

Louis Sickler
louis....@starz.com

Cory Sane [TeamSybase]

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Dec 11, 2009, 11:30:36 PM12/11/09

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Louis,
I don't have a final answer for you, but what is your /proc/cpu file showing for cpu count?
I like the fact that you plan to run only the dbms on the box.
This may be a case where you test 4 and 8 and see if 8 is really any better.

--
Cory Sane
[TeamSybase]
Certified Sybase Associate DBA for ASE 15.0
"Louis Sickler" wrote in message news:4b22bfbe.70c...@sybase.com...

louissickler

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Dec 14, 2009, 3:40:16 PM12/14/09

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[sybase@spldb02 ~]$ cat /proc/cpuinfo
processor : 0
vendor_id : AuthenticAMD
cpu family : 15
model : 65
model name : Dual-Core AMD Opteron(tm) Processor 2216
HE
stepping : 3
cpu MHz : 1000.000
cache size : 1024 KB
physical id : 0
siblings : 2
core id : 0
cpu cores : 2
fpu : yes
fpu_exception : yes
cpuid level : 1
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic
sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht
syscall nx mmxext fxsr_opt rdtscp lm 3dnowext 3dnow pni cx16
lahf_lm cmp_legacy svm extapic cr8_legacy
bogomips : 2000.07
TLB size : 1024 4K pages
clflush size : 64
cache_alignment : 64
address sizes : 40 bits physical, 48 bits virtual
power management: ts fid vid ttp tm stc

processor : 1
vendor_id : AuthenticAMD
cpu family : 15
model : 65
model name : Dual-Core AMD Opteron(tm) Processor 2216
HE
stepping : 3
cpu MHz : 1000.000
cache size : 1024 KB
physical id : 1
siblings : 2
core id : 0
cpu cores : 2
fpu : yes
fpu_exception : yes
cpuid level : 1
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic
sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht
syscall nx mmxext fxsr_opt rdtscp lm 3dnowext 3dnow pni cx16
lahf_lm cmp_legacy svm extapic cr8_legacy
bogomips : 2000.07
TLB size : 1024 4K pages
clflush size : 64
cache_alignment : 64
address sizes : 40 bits physical, 48 bits virtual
power management: ts fid vid ttp tm stc

processor : 2
vendor_id : AuthenticAMD
cpu family : 15
model : 65
model name : Dual-Core AMD Opteron(tm) Processor 2216
HE
stepping : 3
cpu MHz : 1000.000
cache size : 1024 KB
physical id : 0
siblings : 2
core id : 1
cpu cores : 2
fpu : yes
fpu_exception : yes
cpuid level : 1
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic
sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht
syscall nx mmxext fxsr_opt rdtscp lm 3dnowext 3dnow pni cx16
lahf_lm cmp_legacy svm extapic cr8_legacy
bogomips : 2000.07
TLB size : 1024 4K pages
clflush size : 64
cache_alignment : 64
address sizes : 40 bits physical, 48 bits virtual
power management: ts fid vid ttp tm stc

processor : 3
vendor_id : AuthenticAMD
cpu family : 15
model : 65
model name : Dual-Core AMD Opteron(tm) Processor 2216
HE
stepping : 3
cpu MHz : 1000.000
cache size : 1024 KB
physical id : 1
siblings : 2
core id : 1
cpu cores : 2
fpu : yes
fpu_exception : yes
cpuid level : 1
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic
sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht
syscall nx mmxext fxsr_opt rdtscp lm 3dnowext 3dnow pni cx16
lahf_lm cmp_legacy svm extapic cr8_legacy
bogomips : 2000.07
TLB size : 1024 4K pages
clflush size : 64
cache_alignment : 64
address sizes : 40 bits physical, 48 bits virtual
power management: ts fid vid ttp tm stc

Sherlock, Kevin [TeamSybase]

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Dec 15, 2009, 11:40:50 AM12/15/09

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Louis,
You have two physical processors:

grep 'physical id' /proc/cpuinfo | sort -u

physical id : 0
physical id : 1

Each physical processor has 2 cores (which gives you 4 logical processors,
below):

grep 'cpu cores' /proc/cpuinfo

cpu cores : 2
cpu cores : 2
cpu cores : 2
cpu cores : 2

alternatively, you could look at each core per physical processor:

egrep 'physical id|core id' cpuinfo

physical id : 0
core id : 0
physical id : 1
core id : 0
physical id : 0
core id : 1
physical id : 1
core id : 1

This gives you four "logical processors" :

grep "^processor" /proc/cpuinfo

processor : 0
processor : 1
processor : 2
processor : 3

So, it looks to me like you have two dual-core processors resulting in 4
cores available. The only way you could get to 8 logical processors is if
you turn on hyperthreading (ht flag indicated in "flags" field). However, I
wouldn't do that. I'd stick with 4 engines on 4 non-hyperthreaded cores.
If you were told (by the vendor?) that you have 4 physical dual-core
processors, perhaps there are 2 that are not enabled in the kernel? You
might want to look at the startup log and see if there were more processors
detected than started/enabled:

dmesg | grep -i "processor"

<Louis Sickler> wrote in message news:4b26a2b0.778...@sybase.com...

Sherlock, Kevin [TeamSybase]

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Dec 15, 2009, 12:14:42 PM12/15/09

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Shows 4 logical processors. In this case, from 2 physical processors
(sockets), each physical processor supporting up to 2 logical processors
(siblings count). Each physical processor has 2 cores. Since "siblings" is
equal to "cpu cores", then either hyperthreading is not supported by these
processors, or it is disabled in the BIOS. The "ht" flag in the output
doesn't necessarily indicate that the processors supports hyperthreading,
but just that "siblings" is a reportable item. If siblings is twice the
value of cpu cores, then the processors support hyperthreading. I don't
think these processors support hyperthreading anyway, so that's not an issue
here. You simply only have 2 physical dual-core processors (4 cores) active
on this system.

"Sherlock, Kevin [TeamSybase]" <kevin.s...@teamsybase.com> wrote in
message news:4b27bc12$1@forums-1-dub...

louissickler

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Dec 15, 2009, 3:57:38 PM12/15/09

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Thanks guys. That makes perfect sense, I picked up this
project from someone else so I did not order the hardware or
anything it was all built when I got it. Anyway, the info
is much appreciated and makes sense I will confirm with my
SA that it's 2 dual core CPU's.