DB Tuning...

On Thu, 29 Jul 2004 13:23:38 -0400, Anthony Presley wrote: > With the light of query tuning, lately, I've decided to submit my server's > config for some review ... to see if someone would be willing to help me > tune it a bit. Tuning is pretty good. Here are your metrics: BR = (24306 / (32278143 + 622031)) * 100.00 = .0700 ! Excellent BTR = (((32278143 + 622031) / 100000) / 61.817) = 5.3221 ! On target RAU = (221553/(120432+12182+90586)) * 100.00 = 99.2600 ! Just a bit low I'd just suggest reducing RA_THRESHOLD from 24 to 16 or even 8 to get your RAU closer to 100%. > Without further ado -- here it is. > > It's a dual AMD Athlon XP 2400 (I believe) running Linux Software RAID w/ > Mirroring (IDE). We're moving to a RAID 5 (hardware) setup over the next AAAAAAAAAAHHHHHHHHHHHHH!!!!!!!!!!! NO RAID5! NO RAID5! NO RAID5! NO RAID5! NO RAID5! NO RAID5! NO RAID5! RAID5 and databases do not get along performance wise and they are NOT SAFE for your data. Use RAID10 instead! Search the CDI archives for my RAID5 RANT or find it on the BAARF web site: www.baarf.com along with several other papers on the subject. > few months. At which point, I'll probably leave the log's and tmp dbspace's > on the mirrored drives. The system has 2GB of RAM. We also run an instance > of Postgres and one of MySQL (web apps). And, also running on the box is > Tomcat / Apache w/ a web interface to get to the Informix DB. Overall, > though, the Informix tuning is the one I'm least familiar with .... and > probably the most important. Oh -- every path w/in the onconfig file is a > symlink, in case we need to move it ... sometime. > > This is 7.31.UD2, IDS. Art S. Kagel

With the light of query tuning, lately, I've decided to submit my server's config for some review ... to see if someone would be willing to help me tune it a bit. Without further ado -- here it is. It's a dual AMD Athlon XP 2400 (I believe) running Linux Software RAID w/ Mirroring (IDE). We're moving to a RAID 5 (hardware) setup over the next few months. At which point, I'll probably leave the log's and tmp dbspace's on the mirrored drives. The system has 2GB of RAM. We also run an instance of Postgres and one of MySQL (web apps). And, also running on the box is Tomcat / Apache w/ a web interface to get to the Informix DB. Overall, though, the Informix tuning is the one I'm least familiar with .... and probably the most important. Oh -- every path w/in the onconfig file is a symlink, in case we need to move it ... sometime. This is 7.31.UD2, IDS. Thanks for any advice / help. ----------------------------------------------------------- onconfig: # Root Dbspace Configuration ROOTNAME rootdbs # Root dbspace name ROOTPATH /db0/dbroot0 # Path for device containing root dbspace ROOTOFFSET 0 # Offset of root dbspace into device (Kbytes) ROOTSIZE 1000000 # Size of root dbspace (Kbytes) # Disk Mirroring Configuration Parameters MIRROR 0 # Mirroring flag (Yes = 1, No = 0) MIRRORPATH # Path for device containing mirroredroot MIRROROFFSET 0 # Offset into mirrored device (Kbytes) # Physical Log Configuration PHYSDBS dblog0 # Location (dbspace) of physical log #PHYSFILE 99000 # Physical log file size (Kbytes) PHYSFILE 990000 # Physical log file size (Kbytes) # Logical Log Configuration LOGFILES 10 # Number of logical log files LOGSIZE 950000 # Logical log size (Kbytes) # Diagnostics MSGPATH /var/log/online.log # System message log file path CONSOLE /dev/console # System consolemessage path ALARMPROGRAM /opt/informix/etc/eventalarm # Alarm program path SYSALARMPROGRAM /opt/informix/etc/evidence.sh # System Alarm program path TBLSPACE_STATS 0 # System Archive Tape Device #TAPEDEV /dev/nulltape # Tape device path TAPEDEV /home/informix/logs/archive # Tape device path TAPEBLK 512 # Tape block size (Kbytes) TAPESIZE 2000000 # Maximum amount of data to put on tape (Kbytes) # Log Archive Tape Device LTAPEDEV /home/informix/logs/log # Log tape device path LTAPEBLK 512 # Log tape block size (Kbytes) LTAPESIZE 2000000 # Max amount of data to put on log tape (Kbytes) # Optical STAGEBLOB # Informix Dynamic Server/Optical staging area # System Configuration SERVERNUM 0 # Unique id corresponding to a DynamicServer instance DBSERVERNAME london # Name of default database server DBSERVERALIASES london_net # List of alternate dbservernames DEADLOCK_TIMEOUT 60 # Max time to wait of lock indistributed env. RESIDENT 1 # Forced residency flag (Yes = 1, No = 0) NETTYPE ipcshm,1,690,CPU NETTYPE soctcp,1,690,NET MULTIPROCESSOR 1 # 0 for single-processor, 1 formulti-processor NUMCPUVPS 2 # Number of user (cpu) vps SINGLE_CPU_VP 0 # If non-zero, limit number of cpu vpsto one NOAGE 0 # Process aging AFF_SPROC 0 # Affinity start processor AFF_NPROCS 0 # Affinity number of processors # Shared Memory Parameters LOCKS 300000 # Maximum number of locks BUFFERS 100000 # Maximum number of shared buffers NUMAIOVPS 20 # Number of IO vps PHYSBUFF 48 # Physical log buffer size (Kbytes) LOGBUFF 32 # Logical log buffer size (Kbytes)LOGSMAX 10 # Maximum number of logical log files CLEANERS 75 # Number of buffer cleaner processes SHMBASE 0x10000000L # Shared memory base address SHMVIRTSIZE 16384 # initial virtual shared memorysegment size SHMADD 16384 # Size of new shared memory segments (Kbytes) SHMTOTAL 0 # Total shared memory (Kbytes). 0=>unlimited CKPTINTVL 300 # Check point interval (in sec) LRUS 65 # Number of LRU queues LRU_MAX_DIRTY 30 # LRU percent dirty begin cleaninglimit LRU_MIN_DIRTY 20 # LRU percent dirty end cleaning limit#LRU_MAX_DIRTY 5 # LRU percent dirty begin cleaning limit #LRU_MIN_DIRTY 1 # LRU percent dirty end cleaning limit LTXHWM 50 # Long transaction high water markpercentage LTXEHWM 60 # Long transaction high water mark (exclusive) TXTIMEOUT 300 # Transaction timeout (in sec) STACKSIZE 32 # 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 workerthreads ON_RECVRY_THREADS 1 # Default number of online workerthreads # Data Replication Variables # DRAUTO: 0 manual, 1 retain type, 2 reverse type DRAUTO 0 # DR automatic switchover DRINTERVAL 30 # DR max time between DR buffer flushes (in sec) DRTIMEOUT 30 # DR network timeout (in sec) DRLOSTFOUND /opt/informix/etc/dr.lostfound # DR lost+found filepath # CDR Variables CDR_LOGBUFFERS 2048 # size of log reading buffer pool (Kbytes) CDR_EVALTHREADS 1,2 # evaluator threads (per-cpu-vp,additional) CDR_DSLOCKWAIT 5 # DS lockwait timeout (seconds) CDR_QUEUEMEM 4096 # Maximum amount of memory for any CDR queue (Kbytes) # Backup/Restore variables BAR_ACT_LOG /tmp/bar_act.log BAR_MAX_BACKUP 0 BAR_RETRY 1 BAR_NB_XPORT_COUNT 10 BAR_XFER_BUF_SIZE 31 # Informix Storage Manager variables ISM_DATA_POOL ISMData # If the data pool name is changed, be sure to # update $INFORMIXDIR/bin/onbar. Change to # ism_catalog -create_bootstrap -pool <new name> ISM_LOG_POOL ISMLogs # Read Ahead Variables RA_PAGES 32 # Number of pages to