RE: Buffer Waits Ratio

I misspoke when I explained the Buffer Waits Ratio. That is what I get for trying to hurry up and finish a post before I go home :). I am pretty sure it uses page reads and buffer writes because those are the two things which need exclusive access to an LRU queue. But I am not sure. Will >>===== Original Message From "Henderson, Scott" <SHenderson@purolator.com> >===== >>Friends, >> >> >>Informix Version: 7.30 FC7 >>OS: HPUX 11.0 >>Hardware: HP9000 Series 800 V2500 >>Disk Array: EMC 3700 >>Application: OLTP (strictly database server) >>Misc. 16 CPU, 8GB mem, 2 instances >> >> >>I've been making use of the bufwait ratio formula [ratio = (bufwaits / >>(pagreads + bufwrits)) * 100] on my production servers. During normal day >>to day usage it hovers at around 15%. I know the ideal target is 10%. >>During heavy activity in the afternoon I have seen measurements of >25%. I >>plan to increase BUFFERS,LRUS and CLEANERS and maybe NUMCPUVPS. I would >>appreciate if you guys/gals confirm my plan and also have a look at my >>onconfig file and recommend any improvements. >> >>Informix recommends 4 LRUS per NUMCPUVPS (Admin Guide Vol2 33-45) >>I have 6 CPUVPS, 28 LRUS (whoops) looking after 100000 BUFFERS, each LRU is >>looking after approximately 7000 pages. >>So, my questions are; >> >>1) Should I conform to the 4 LRUS/NUMCPUVPS? >>2) Is 7000 BUFFERS a high/low number of pages for each LRU, is there an >>optimized target? >> >>Also, could someone explain to me why the formula uses pagreads and not >>bufreads. >> >> >> >> >> >>#************************************************************************** >># >># INFORMIX SOFTWARE, INC. >># >># Title: onconfig.prod >># Description: Informix Dynamic Server Configuration Parameters >># >>#************************************************************************** >> >># Root Dbspace Configuration >> >>ROOTNAME rootdbs # Root dbspace name >>ROOTPATH /dev/ifn_110001 # Path for device containing root>>dbspace >> >> >>ROOTOFFSET 0 # Offset of root dbspace into device >>(Kbytes) >>ROOTSIZE 200000 # Size of root dbspace (Kbytes)>> >># Disk Mirroring Configuration Parameters >> >>MIRROR 1 # Mirroring flag (Yes = 1, No = 0) >>MIRRORPATH # Path for device containing mirrored root >>MIRROROFFSET 0 # Offset into mirrored device (Kbytes)>> >># Physical Log Configuration >> >>PHYSDBS plogdbs # Location (dbspace) of physical log >>PHYSFILE 49890 # Physical log file size (Kbytes)>> >># Logical Log Configuration >> >>LOGFILES 100 # Number of logical log files >>LOGSIZE 5000 # Logical log size (Kbytes)>> >># Diagnostics >> >>MSGPATH /home/informix/log/ccd.log # System message log >file >>path >>CONSOLE /dev/console # System console>message >>path >>ALARMPROGRAM /opt/informix_7.30/etc/no_log.sh # Alarm program path >>SYSALARMPROGRAM /opt/informix_7.30/etc/evidence.sh # System Alarm >>program path >>TBLSPACE_STATS 1>> >># System Archive Tape Device >> >>#TAPEDEV /dev/null # Tape device path >>TAPEDEV /dev/rmt/c11t1d0BESTb # Tape device path >>#TAPEDEV /dev/rmt/c11t2d0BESTb # Tape device path >>TAPEBLK 64 # Tape block size (Kbytes) >>TAPESIZE 71303168 # Maximum amount of data to put on >>tape (Kbytes)>> >># Log Archive Tape Device >> >>#LTAPEDEV /dev/null # Log tape device path >>LTAPEDEV /prod/informix/llogs/ccd/llog.today # Log tape >>device path >>LTAPEBLK 64 # Log tape block size (Kbytes) >>LTAPESIZE 2048000 # Max amount of data to put on log tape >>(Kbytes)>> >># Optical >> >>STAGEBLOB # Informix Dynamic Server/Optical staging >>area >> >># System Configuration >> >>SERVERNUM 13 # Unique id corresponding to a Dynamic>>Server instance >>DBSERVERNAME cortran0 # Name of default database server >>DBSERVERALIASES cortran1 # List of alternate>dbservernames >>NETTYPE soctcp,1,100,NET # Configure poll>>thread(s) for nettype >>DEADLOCK_TIMEOUT 60 # Max time to wait of lock in distributed >>env. >>RESIDENT 1 # Forced residency flag (Yes = 1, No = 0) >> >>MULTIPROCESSOR 1 # 0 for single-processor, 1 for>>multi-processor >>NUMCPUVPS 6 # Number of user (cpu) vps >>SINGLE_CPU_VP 0 # If non-zero, limit number of cpu vps to>>one >> >>NOAGE 0 # Process aging >>AFF_SPROC 0 # Affinity start processor >>AFF_NPROCS 0 # Affinity number of processors>> >># Shared Memory Parameters >> >>LOCKS 400000 # Maximum number of locks >>BUFFERS 100000 # Maximum number of shared buffers >>NUMAIOVPS 24 # Number of IO vps >>PHYSBUFF 64 # Physical log buffer size (Kbytes) >>LOGBUFF 64 # Logical log buffer size >(Kbytes)>>LOGSMAX 1024 # Maximum number of logical log files >>CLEANERS 24 # Number of buffer cleaner>>processes >>SHMBASE 0x0 # Shared memory base address >>SHMVIRTSIZE 500000 # initial virtual shared memory segment size >>SHMADD 65536 # Size of new shared memory segments >>(Kbytes) >>SHMTOTAL 2000000 # Total shared memory (Kbytes). 0=>unlimited >>CKPTINTVL 180 # Check point interval (in sec) >>LRUS 28 # Number of LRU queues >>LRU_MAX_DIRTY 2 # LRU percent dirty begin cleaning limit >>LRU_MIN_DIRTY 1 # LRU percent dirty end cleaning limit >>LTXHWM 50 # Long transaction high water mark>>percentage >>LTXEHWM 60 # Long transaction high water>mark >>(exclusive) >>TXTIMEOUT 300 # Transaction timeout (in sec) >>STACKSIZE 256 # Stack size (Kbytes)>> >># System Page Size >># BUFFSIZE - Dynamic Server no longer supports this configuration parameter. >># To determine the page size used by Dynamic Server on your >>platform >># see the last line of output from the command, 'onstat -b'. >> >> >># Recovery Variables >># OFF_RECVRY_THREADS: >># Number of parallel worker threads during fast recovery or an offline >>restore. >># ON_RECVRY_THREADS: >># Number of parallel worker threads during an online restore. >> >>OFF_RECVRY_THREADS 10 # Default number of offline worker threads >>ON_RECVRY_THREADS