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3 Replies Latest reply: Nov 12, 2012 5:33 AM by 856103 RSS

Kernel Parameter Impact on Timesten Performance

856103 Newbie
Currently Being Moderated
Hi,

Can you please guide me on the impact of certain kernel/hardware parameters on Timesten performance :

kernel.shmmax
kernel.shmall
kernel.msgmni
kernel.shmmni

I have two servers with the same Timesten DSN configuration. A particular process takes 15 ms on one server (Server A) and 5 ms (Server B) on the other. The Timesten and linux versions on both are similar. Memory is the same (32 GB). DSN parameters are exactly same as well.


On comparing cpuinfo and sysctl.conf i found the following differences :
Server A

cpuinfo
processor     : 23
vendor_id     : GenuineIntel
cpu family     : 6
model          : 46
model name     : Intel(R) Xeon(R) CPU E7540 @ 2.00GHz
stepping     : 6
cpu MHz          : 1064.000
cache size     : 18432 KB
cpu cores     : 6

sysctl.conf

kernel.shmmax = 68719476736
kernel.shmall = 4294967296
kernel.msgmni=1000
net.core.wmem_max=4194304
Server B

cpuinfo
processor     : 15
vendor_id     : GenuineIntel
cpu family     : 6
model          : 44
model name     : Intel(R) Xeon(R) CPU E5620 @ 2.40GHz
stepping     : 2
cpu MHz          : 2400.000
cache size     : 12288 KB
cpu cores     : 4

sysctl.conf

kernel.shmmax = 17179869184
kernel.shmall = 17179869184
kernel.msgmni=100000
kernel.shmmni = 4096
net.core.wmem_max = 1048576
Timesten Version - TimesTen Release 11.2.1.8.0 (64 bit Linux/x86_64)
DSN Parameters :

Driver=/application/matrix/TimesTen/matrix/lib/libtten.so
DataStore=/application/matrix/TimesTen/DAIWAPRODV7_DSN_datastore/DAIWAPRODV7_DSN_DS_DIR
LogDir=/logs_timeten/DAIWAPRODV7_DSN_logdir
PermSize=8000
TempSize=250
PLSQL=1
DatabaseCharacterSet=WE8MSWIN1252
OracleNetServiceName=fodbprod
Connections=500
PassThrough=0
SQLQueryTimeout=250
LogBufMB=1024
LogFileSize=1024
LogPurge=1
PLSQL_MEMORY_SIZE=1000
PLSQL_CONN_MEM_LIMIT=2000
Regards,
Karan
  • 1. Re: Kernel Parameter Impact on Timesten Performance
    ChrisJenkins Guru
    Currently Being Moderated
    Hi Karan,

    Those kernel parameters won't affect performance. They will simply affect how much shared memory, messages and semaphores are configured in the kernel. This may affect whether a particular TimesTen datastore can be loaded into memory or not but if it loads then they have no real effect on performance.

    The difference in performance is due to this:

    model name     : Intel(R) Xeon(R) CPU E7540 @ *2.00GHz*
    stepping     : 6
    cpu MHz          : *1064.000*
    cache size     : 18432 KB
    cpu cores     : 6

    versus this:

    model name     : Intel(R) Xeon(R) CPU E5620 @ *2.40GHz*
    stepping     : 2
    cpu MHz          : *2400.000*
    cache size     : 12288 KB
    cpu cores     : 4

    The second machine has a significantly faster CPU...

    Chris

    Edited by: ChrisJenkins on Nov 12, 2012 12:01 PM
  • 2. Re: Kernel Parameter Impact on Timesten Performance
    Tim Vincent Explorer
    Currently Being Moderated
    Hi Karan,

    The OS kernel parameters don't really have an impact on performance, they are more around OS memory resources management.

    TimesTen is very 'lightweight' in terms of the CPU cycles used to access data. Therefore as a generalisation on a single thread we typically see the faster the CPU the faster TimesTen will go. As below Server B has a faster CPU, so would expect a single thread to be faster here than on Server A.

    Tim
  • 3. Re: Kernel Parameter Impact on Timesten Performance
    856103 Newbie
    Currently Being Moderated
    Thanks Chris/Tim ..

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