Re: Spin locks bringing system to a crawl

Jay, Your spin locks look fine. The most critical number is Avg Loop/Wait which should be low. That you see a long list of spin locks is normal for a large and heavily loaded system. The profile shows a high number of sequential scans. This might be worth looking into if it increases too fast with time. But I doubt that this is your main problem either. Can you be more specific about your "decrease in performance"? How high is your cpu and disk load (sar -u, -d on most systems)? What are the symptoms that bother you? Michael Jay wrote: > Hi, > > I'm having a major decrease in performance, and I'm wondering if the number > of spin locks (725 entries in onstat -g spi of "fast mutex, bhash") are > contributing to this. > > Enviroment > Informix 7.24 (I know we must upgrade, but unfortunatly it's not my descion > to as when), AIX 4.3.3, 4 CPUs, 1GB RAM, 8 disks no mirror or stripes and > volitile tables fragmented by round robin across 4 disks (indexes for these > tables are on seperate a disk). > > I am really hoping someone can help me! > > Thanks in advance > > J. > > # Root Dbspace Configuration > > ROOTNAME rootdbs # Root dbspace name> ROOTPATH /dev/prod2_rootdbs # Path for device containing root > dbspace > ROOTOFFSET 0 # Offset of root dbspace into device > (Kbytes) > ROOTSIZE 1024000 # Size of root dbspace (Kbytes)> > # Disk Mirroring Configuration Parameters > > MIRROR 0 # Mirroring flag (Yes = 1, No = 0) > MIRRORPATH # Path for device containing mirrored root > MIRROROFFSET 0 # Offset into mirrored device (Kbytes)> > # Physical Log Configuration > > PHYSDBS rootdbs # Location (dbspace) of physical log > PHYSFILE 80000 # Physical log file size (Kbytes)> > # Logical Log Configuration > > LOGFILES 6 # Number of logical log files > LOGSIZE 45000 # Logical log size (Kbytes)> > # Diagnostics > > MSGPATH /isgprod2/inf7dev/online.log # System message log file path > CONSOLE /isgprod2/inf7dev/console.log # System console message path > ALARMPROGRAM /isgprod2/inf7dev/etc/no_log.sh # Alarm program path > > # System Archive Tape Device > > TAPEDEV /dev/rmt1 # Tape device path > TAPEBLK 512 # Tape block size (Kbytes) > TAPESIZE 20971520 #Maximum amount of data to put on tape > (kbytes)> > # Log Archive Tape Device > > LTAPEDEV /dev/null # Log tape device path > LTAPEBLK 512 # Log tape block size (Kbytes) > LTAPESIZE 12582412 # Max amount of data to put on log tape > (Kbytes)> > # Optical > > STAGEBLOB # INFORMIX-OnLine/Optical staging area > > # System Configuration > > SERVERNUM 0 # Unique id corresponding to a OnLine> instance > DBSERVERNAME aixprod2_on # Name of default database server > DBSERVERALIASES rt_aixprod2_on # List of alternate dbservernames > DEADLOCK_TIMEOUT 60 # Max time to wait of lock in distributed > env. > RESIDENT 0 # Forced residency flag (Yes = 1, No = 0) > > MULTIPROCESSOR 1 # 0 for single-processor, 1 for> multi-processor > NUMCPUVPS 4 # 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 10000 # Maximum number of locks> #BUFFERS 8000 # Maximum number of shared buffers > BUFFERS 100000 > NUMAIOVPS 6 # Number of IO vps > PHYSBUFF 64 # Physical log buffer size (Kbytes) > LOGBUFF 64 # Logical log buffer size (Kbytes)> LOGSMAX 6 # Maximum number of logical log files > CLEANERS 6 # Number of buffer cleaner processes > SHMBASE 0x30000000 # Shared memory base address > SHMVIRTSIZE 98304 # initial virtual shared memory segment 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 32 # 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 0x12c # Transaction timeout (in sec) > STACKSIZE 64 # Stack size (Kbytes)> > # System Page Size > # BUFFSIZE - OnLine no longer supports this configuration parameter. > # To determine the page size used by OnLine 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 1 # Default number of online worker threads> > # 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 /isgprod2/inf7dev/etc/dr.lostfound # DR lost+found file path > > # 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> > # Read Ahead Variables > RA_PAGES 32 # Number of pages to attempt to read ahead > RA_THRESHOLD 30 # Number of pages left before next group> > # DBSPACETEMP: > # OnLine equivalent of DBTEMP for SE. This is the list of dbspaces > # that the OnLine SQL Engine will use to create temp tables etc. > # If specified it must be a colon separated list of dbspaces that exist > # when the OnLine system is brought online. If not specified, or if > # all dbspace