Re: Informix Performance
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You seem to have many misconfigurations on your Informix server !!!
Start investigating the following areas !
1. Why are u using cooked files ?
2. How does your onstat -g seg looks like when the slow down happens ?
3. Check all the processes that are running when the slow down happens. Backups, update statistics, batch jobs etc etc.
4. How does the onstat -u look like when the slow down happens. Are there processes waiting for buffers ?
5. What kind of locking are you using ? Page level locks, row locks etc.
6. When users complain of slowness you need to see what they are trying to do and check if the tables they are trying to hit are locked at the time.
7. When the slowness happens are there logical logs that have not been backep up ?
8. Did you change any /etc/system parameters ? If so did u reboot the Unix server after doing so ?
9. How does your onstat -g ntt look like ? Does it show processes that are very old and just sitting there ?
10. What kind of connections are you using and how many ? Is your Nettype paramer configured correctly ? By the way you don't even show NETTYPE parameter on your onconfig file that you have pasted here.
11. Have you tried the add extra CPUVPS dynamically when slowness happens.
12. Is your TEMP dpspace big enough ? Can you add more TEMP spaces and monitor the system. Its better to have several TEMP spaces rather than having one big TEMP space.
13. Increase the CLEANERS to 5 or 6 and monitor the system.
14. From the OS side when you issue sar command does it show that OS is waiting for block writes ?
15. Check onstat -g dic, mem, stk, ses to figure out the memory and caching by process.
16. Reset your profile counts using onstat -z and monitor onstat -p
17. Use ipcs to lookat memory from OS side and see if there is memory allocated other stuff other than Informix and investigate.
18. See if u are allocating enough semophores at the IDS start.
Those abvoe thoughts are some things to check to start with.
Ravi Thero
Daniel Castro <daniel.castro@feliciorocho.org.br> wrote:
Hi,
I am having informix performance problems. I don't know where to
start.
Sometimes the database hangs, always from 00:00am to 5:00 am, but it
gives no error in the log file. Can you help me?
Sometimes the users says that the system is slow, but I can't identify
why.
First, the result of onstat -p:
Informix Dynamic Server Version 9.30.UC1 -- On-Line -- Up 9 days
21:06:09 -- 1582656 Kbytes
Profile
dskreads pagreads bufreads %cached dskwrits pagwrits bufwrits %cached
67223627 173897813 2077681908 96.76 12042759 61104633 222993237
94.60
isamtot open start read write rewrite delete commit
rollbk
2790216351 184683421 616967012 4148277112 65017319 12219659 28562330
8807460 884
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
7 0 0 336038.88 116702.45 1385 4099
bufwaits lokwaits lockreqs deadlks dltouts ckpwaits compress
seqscans
7192942 14028 903998567 4 0 6224 6824574
39496093
ixda-RA idx-RA da-RA RA-pgsused lchwaits
12311760 5075181 15389056 32074507 56519934
Second my onconfig file:
#**************************************************************************
#
# INFORMIX SOFTWARE, INC.
#
# Title: onconfig.producao
# Description: Informix Dynamic Server Configuration Parameters
#
#**************************************************************************
# Root Dbspace Configuration
ROOTNAME rootdbs # Root dbspace nameROOTPATH /cooked_file/dbs_rootP # Path for device containing
root dbspace
ROOTOFFSET 0 # Offset of root dbspace into device
(Kbytes)
ROOTSIZE 471039 # 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 wpdphlog # Location (dbspace) of physical log
PHYSFILE 60000 # Physical log file size (Kbytes)# Logical Log Configuration
LOGFILES 40 # Number of logical log files
LOGSIZE 10000 # Logical log size (Kbytes)# Diagnostics
MSGPATH /opt/informix/producao.log # System message log file
path
CONSOLE /dev/console # System console message path
ALARMPROGRAM /opt/informix/etc/log_full.sh # Alarm program path
TBLSPACE_STATS 1 # Maintain tblspace statistics# System Archive Tape Device
TAPEDEV /dev/st0 # Tape device path
TAPEBLK 16 # Tape block size (Kbytes)
TAPESIZE 100000000 # Maximum amount of data to put on
tape (Kbytes)# Log Archive Tape Device
LTAPEDEV /dev/st0 # Log tape device path
LTAPEBLK 16 # Log tape block size (Kbytes)
LTAPESIZE 100000000 # Max amount of data to put on log
tape (Kbytes)
# OpticalSTAGEBLOB # Informix Dynamic Server staging area
# System Configuration
SERVERNUM 1 # Unique id corresponding to a OnLineinstance
DBSERVERNAME producao # Name of default database server
DBSERVERALIASES # List of alternate dbservernames
DEADLOCK_TIMEOUT 60 # Max time to wait of lock indistributed env.
RESIDENT 0 # Forced residency flag (Yes = 1, No =
0)
MULTIPROCESSOR 1 # 0 for single-processor, 1 formulti-processor
# NUMCPUVPS 1 # 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 200000 # Maximum number of locks
BUFFERS 600000 # Maximum number of shared buffers# NUMAIOVPS # Number of IO vps
PHYSBUFF 128 # Physical log buffer size (Kbytes)
LOGBUFF 128 # Logical log buffer size (Kbytes)
CLEANERS 4 # Number of buffer cleaner processes
SHMBASE 0x50000000 # Shared memory base address
SHMVIRTSIZE 154000 # initial virtual shared memorysegment size
SHMADD 32768 # Size of new shared memory segments
(Kbytes)
SHMTOTAL 0 # Total shared memory (Kbytes).
0=>unlimited
CKPTINTVL 600 # Check point interval (in sec)
LRUS 64 # Number of LRU queues
LRU_MAX_DIRTY 3 # LRU percent dirty begin cleaninglimit
LRU_MIN_DIRTY 1 # LRU percent dirty end cleaning limit
TXTIMEOUT 0x12c # Transaction timeout (in sec)
STACKSIZE 32 # 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 workerthreads
ON_RECVRY_THREADS 1 # Default number of online workerthreads
# Data Replication Variables
DRINTERVAL 30 # DR max time between DR buffer
flushes (in sec)
DRTIMEOUT 30 # DR network timeout (in sec)
DRLOSTFOUND /usr/informix/etc/dr.lostfound # DR lost+found filepath
# CDR Variables
CDR_EVALTHREADS 1,2 # evaluator thr