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  1. #1
    Join Date
    Jul 2007
    Posts
    4

    Unanswered: sybase server ase 12_5 slow

    I've a sybase server ase 12_5 which normally runs smooth(for weeks), but sometimes sudently it gets very slow and with a lot of locks. The time of the day does not match with the time of checking storage neither with the backup.

    I've searched in sybase server log file and I didn't found anything relevant. How can I investigate this problem? I'm using sybmon to check processes, but I don't see anything relevant too, only the locks.

    The only thing relevant I found was in the output of optdiag which shows some indexes for the most used table in the system with parameter Large I/O efficiency low.


    The sybase server is running in a 2 cpu server with HT and with 3gb.
    There are 3 engines set up. Althought when system gets slow only one shows 99% usage in top. Why is this appening? shouldn't all 3 dataserver processes get 99% usage in such situation?

    Any help would be welcome

    Regards

    Aditional system description:

    ucwimp:~ # hwinfo --memory
    01: None 00.0: 10102 Main Memory
    [Created at memory.59]
    Unique ID: rdCR.CxwsZFjVASF
    Hardware Class: memory
    Model: "Main Memory"
    Memory Range: 0x00000000-0xcff0afff (rw)
    Memory Size: 3 GB + 256 MB
    Config Status: cfg=no, avail=yes, need=no, active=unknown

    ucwimp:~ # hwinfo --cpu
    01: None 00.0: 10103 CPU
    [Created at cpu.290]
    Unique ID: rdCR.j8NaKXDZtZ6
    Hardware Class: cpu
    Arch: Intel
    Vendor: "GenuineIntel"
    Model: 15.4.10 "Intel(R) Xeon(TM) CPU 3.60GHz"
    Features: fpu,vme,de,pse,tsc,msr,pae,mce,cx8,apic,sep,mtrr,p ge,mca,cmov,pat,pse36,clflush,dts,acpi,mmx,fxsr,ss e,sse2,ss,ht,tm,pbe,nx,lm,pni,monitor,ds_cpl,tm2,e st,cid
    Clock: 3600 MHz
    Cache: 2048 kb
    Units/Processor: 2
    Config Status: cfg=new, avail=yes, need=no, active=unknown

    02: None 01.0: 10103 CPU
    [Created at cpu.290]
    Unique ID: wkFv.j8NaKXDZtZ6
    Hardware Class: cpu
    Arch: Intel
    Vendor: "GenuineIntel"
    Model: 15.4.10 "Intel(R) Xeon(TM) CPU 3.60GHz"
    Features: fpu,vme,de,pse,tsc,msr,pae,mce,cx8,apic,sep,mtrr,p ge,mca,cmov,pat,pse36,clflush,dts,acpi,mmx,fxsr,ss e,sse2,ss,ht,tm,pbe,nx,lm,pni,monitor,ds_cpl,tm2,e st,cid
    Clock: 3600 MHz
    Cache: 2048 kb
    Units/Processor: 2
    Config Status: cfg=new, avail=yes, need=no, active=unknown

    03: None 02.0: 10103 CPU
    [Created at cpu.290]
    Unique ID: +rIN.j8NaKXDZtZ6
    Hardware Class: cpu
    Arch: Intel
    Vendor: "GenuineIntel"
    Model: 15.4.10 "Intel(R) Xeon(TM) CPU 3.60GHz"
    Features: fpu,vme,de,pse,tsc,msr,pae,mce,cx8,apic,sep,mtrr,p ge,mca,cmov,pat,pse36,clflush,dts,acpi,mmx,fxsr,ss e,sse2,ss,ht,tm,pbe,nx,lm,pni,monitor,ds_cpl,tm2,e st,cid
    Clock: 3600 MHz
    Cache: 2048 kb
    Units/Processor: 2
    Config Status: cfg=new, avail=yes, need=no, active=unknown

    04: None 03.0: 10103 CPU
    [Created at cpu.290]
    Unique ID: 4zLr.j8NaKXDZtZ6
    Hardware Class: cpu
    Arch: Intel
    Vendor: "GenuineIntel"
    Model: 15.4.10 "Intel(R) Xeon(TM) CPU 3.60GHz"
    Features: fpu,vme,de,pse,tsc,msr,pae,mce,cx8,apic,sep,mtrr,p ge,mca,cmov,pat,pse36,clflush,dts,acpi,mmx,fxsr,ss e,sse2,ss,ht,tm,pbe,nx,lm,pni,monitor,ds_cpl,tm2,e st,cid
    Clock: 3600 MHz
    Cache: 2048 kb
    Units/Processor: 2
    Config Status: cfg=new, avail=yes, need=no, active=unknown

  2. #2
    Join Date
    Feb 2002
    Location
    Willy is on vacation
    Posts
    1,208
    When you see I/O efficiency low, it is most likely due to fragmentation. Either you have too many DOL tables that have not been REORG'ed or the APL tables have gotten fragmented badly.

    Run an UPDATE STATS first, then check your Cluster Ratio in optdiag. If it is < 0.7 then a good candidate for defrag.

  3. #3
    Join Date
    Jul 2007
    Posts
    4
    The table in question has data row locking scheme, and after I 've run reorg it didn't froze again.Thank you!

    How can I proceed in the same way in order to defragment a All pages locking scheme table? Which command should I use?

  4. #4
    Join Date
    May 2005
    Location
    South Africa
    Posts
    1,365
    Provided Answers: 1
    Create a clustered index then drop it
    Or if it already has a clustered index
    drop and recreate the clustered index

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