checkpoints taking as much as 25 secs
The online log file shows that some checkpoints can take from 4 secs up to
25 secs
but the average is prob 0 secs roughly every 5 mins. The long checkpoint
times prob
occur when some large progs are running e.g. cron jobs. I have not been on
an IDS7
admin course yet so not too sure what to look for. Our system is:
IDS 7.30.UC2 on SCO UnixWare 7.0.1 with 3 pentium pro processors running
RAID 5.
We have approx 10 Gb of dbspace used and the largest table is ~ 3 Gb and our
app
is mostly read only.
I realise raid is not the best option and we may have a disk i/o bottleneck.
It may be that
my question is too general and that it could take a long time to work out
why we are getting
these long checkpoints but if anyone has some clues where to start or what
to check it may
help me a great deal.
Some info may help here:
onstat -p : the bufwaits look high (i done an onstat -z a few days ago) butthis may be normal
Informix Dynamic Server Version 7.30.UC2 -- On-Line -- Up 21:14:51 --
114040 Kbytes
Profile
dskreads pagreads bufreads %cached dskwrits pagwrits bufwrits %cached
26169757 6148644 1242311687 97.89 140931 242136 5077195 97.22
isamtot open start read write rewrite delete commit
rollbk
162742135 3237700 9110352 121063233 2131212 225000 50794 40789
5439
gp_read gp_write gp_rewrt gp_del gp_alloc gp_free gp_curs
0 0 0 0 0 0 0
ovlock ovuserthread ovbuff usercpu syscpu numckpts flushes
0 0 0 37389.09 6435.06 214 508
bufwaits lokwaits lockreqs deadlks dltouts ckpwaits compress seqscans
4750714 2 633141750 0 0 112 29328 384018
ixda-RA idx-RA da-RA RA-pgsused lchwaits
15832893 12764 5910997 21753370 168421
my onconfig file is:
ROOTNAME rootdbsROOTPATH /dev/rdsk/rootdbs
ROOTOFFSET 0
ROOTSIZE 512000MIRROR 0
MIRRORPATH
MIRROROFFSET 0PHYSDBS rootdbs
PHYSFILE 10000
LOGFILES 21
LOGSIZE 5000MSGPATH /users/informix/pluto.log
CONSOLE /users/informix/pluto_console.log
ALARMPROGRAM /users/informix/etc/log_full.sh
SYSALARMPROGRAM /users/informix/etc/evidence.sh
TBLSPACE_STATS 1STAGEBLOB
SERVERNUM 0
DBSERVERNAME pluto
DBSERVERALIASES pluto_net
NETTYPE ipcshm,1,64,CPU
NETTYPE tlitcp,1,10,NET
DEADLOCK_TIMEOUT 60
RESIDENT 0
MULTIPROCESSOR 1
NUMCPUVPS 3
SINGLE_CPU_VP 0
NOAGE 0
AFF_SPROC 0
AFF_NPROCS 0
LOCKS 20000
BUFFERS 42000
NUMAIOVPS 16
PHYSBUFF 120
LOGBUFF 40LOGSMAX 60
CLEANERS 6
SHMBASE 0xa000000
SHMVIRTSIZE 24000
SHMADD 8192
SHMTOTAL 0
CKPTINTVL 300
LRUS 8
LRU_MAX_DIRTY 20
LRU_MIN_DIRTY 15
LTXHWM 45
LTXEHWM 50
TXTIMEOUT 0x12c
STACKSIZE 32
OFF_RECVRY_THREADS 10
ON_RECVRY_THREADS 1
DRAUTO 0
DRINTERVAL 30
DRTIMEOUT 30
DRLOSTFOUND /users/informix/etc/dr.lostfoundCDR_LOGBUFFERS 2048
CDR_EVALTHREADS 1,2
CDR_DSLOCKWAIT 5
CDR_QUEUEMEM 4096
BAR_ACT_LOG /tmp/bar_act.log
BAR_MAX_BACKUP 0
BAR_RETRY 1
BAR_NB_XPORT_COUNT 10
BAR_XFER_BUF_SIZE 31ISM_DATA_POOL ISMData
ISM_LOG_POOL ISMLogs
RA_PAGES
RA_THRESHOLD
DBSPACETEMP tempspace
FILLFACTOR 90
USEOSTIME 0
MAX_PDQPRIORITY 100
DS_MAX_QUERIES
DS_TOTAL_MEMORY
DS_MAX_SCANS 1048576
DATASKIP off
OPTCOMPIND 0
ONDBSPACEDOWN 2LBU_PRESERVE 0
OPCACHEMAX 0
HETERO_COMMIT 0
OPT_GOAL -1
DIRECTIVES 1
RESTARTABLE_RESTORE off