Re(2): Write cache hits slipping !

> Ok, here goes my first EVER attempt at advising on someone elses onconfig, > I'd go with any advice Art gives you ;o)) Good advice more comments below. BTW how many CPU's. > > See below... > > -- > --------------------------------------- > Tony Flaherty aef@mfs.misys.co.uk > Analyst Programmer > Misys Financial Systems > All statements and opinions are my own, > Misys don't pay me enough to have opinions > on their behalf > > . > Alnis Bajars wrote in message ... > >Our environment is a new HP 9000 (R390) server running HP-UX 11.0. We are > >on Dynamic Server, Workgroups Edition, version 7.30.UC9. Our legacy > >application is running on it - it is written in Informix 4GL, and we're on > >version 7.20 of the 4GL/RDS. > > > >We connect to shared memory for our production instance. We have three > >physical disks, mirrored by hardware. All IDS chunks are raw disk logical > >volumes. The first disk has the rootdbs on it (it includes the physical > >log). The second disk is set aside for another application and database. > >The third disk has a number of dbspaces on it. There are 3 three > databases > >in the production instance, and there is a dbspace for each database. > Usage > >peaks at about 80 users, and generally usage is between 6:30 am and 10pm, > >Monday to Friday. > > > >We have ported the system from Standard Engine on an old server, and we > went > >live on Monday, > > > >Our problem (and not a huge one). > > > >On the whole, our new Dynamic Server system has been running great since > it > >went live Monday the 18th October. There's been no downtime since we've > >been live, and no one has been denied access. The onstat commands I have > >run appear to show we have lots and lots of all of the major resources. > > > >Our read cache hits have settled in at just under 99%, which is fantastic. > > > >However, our write cache hits started at just over 57% when we started up > >IDS on the 18th. They climbed to a peak of just under 92% on Wednesday > the > >20th, but have slipped away. They're sitting just over 84% now and still > >falling. > > > >The level of slippage would indicate that it's probably not just the > >application at issue here. > > > >I enclose our current onconfig file and the output of onstat -p and > >onstat -l.> > > >However, my questions are: > >What resources should I be looking at first. > >Which onstat commands should I be running and what should I be looking out > >for. > > > >Thanks in advance. > > > >*** HERE COMES THE ONCONFIG FILE *** > > > ># INFORMIX SOFTWARE, INC. > ># > ># Title: onconfig.clr > ># Description: Informix Dynamic Server Configuration Parameters > ># > ># Alnis Bajars 22/9/99. Modify template for Colorcorp installation. > ># > >#************************************************************************* > * > > > ># Root Dbspace Configuration > > > >ROOTNAME rootdbs # Root dbspace name > >ROOTPATH /dev/chunk_01 # Path for device containing root dbspace > >ROOTOFFSET 0 # Offset of root dbspace into device > >(Kbytes) > >ROOTSIZE 990000 # 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 20000 # Physical log file size (Kbytes)> > > ># Logical Log Configuration > > > >LOGFILES 10 # Number of logical log files > >LOGSIZE 5000 # Logical log size (Kbytes)> > > ># Diagnostics > > > >MSGPATH /opt/informix720/online.log # System message log file path > >CONSOLE /dev/console # System console message path > >ALARMPROGRAM /opt/informix720/etc/log_full.sh # Alarm program path> >SYSALARMPROGRAM /opt/informix720/etc/evidence.sh # System Alarm program > path > >TBLSPACE_STATS 1> > > ># System Archive Tape Device > > > >TAPEDEV /dev/rmt/0m # Tape device path > >TAPEBLK 32 # Tape block size (Kbytes) > >TAPESIZE 24000000 # Maximum amount of data to put on tape > >(Kbytes)> > > ># Log Archive Tape Device > > > >LTAPEDEV /var/dblogs/saturn.log/log_prod # Log tape device path > >LTAPEBLK 32 # Log tape block size (Kbytes) > >LTAPESIZE 500000 # Max amount of data to put on log tape > >(Kbytes)> > > ># Optical > > > >STAGEBLOB # Informix Dynamic Server/Optical staging > >area > > > ># System Configuration > > > >SERVERNUM 1 # Unique id corresponding to a Dynamic> >Server instance > >DBSERVERNAME saturn # Name of default database server > >DBSERVERALIASES # List of alternate dbservernames > >NETTYPE ipcshm,240,120,CPU # Configure poll thread(s) for nettype These values seem to be way out. Art has written some very good articles explaining how this works. I read them with throughly and have forgotten it all :-(( Look on the archive or try something along the lines of NETTYPE ipcshm,3,80,CPU The number of CPU's may also have an effect if I remeber correctly. > >DEADLOCK_TIMEOUT 120 # Max time to wait of lock in distributed > >env. > >RESIDENT 1 # Forced residency flag (Yes = 1, No = 0) > > > >MULTIPROCESSOR 0 # 0 for single-processor, 1 for> >multi-processor > >NUMCPUVPS 3 # Number of user (cpu) vps > >SINGLE_CPU_VP 0 # If non-zero, limit number of cpu vps to> >one Is this is multi cpu machine ? How can you have 3 CPUVPS on one CPU. I know you can but you will take a performance hit. > > > >NOAGE 1 # Process aging > >AFF_SPROC 0 # Affinity start processor > >AFF_NPROCS 0 # Affinity number of processors> > > ># Shared Memory Parameters > > > >LOCKS 100000 # Maximum number of locks > >BUFFERS 100000 # Maximum number of shared buffers > >NUMAIOVPS 30 # Number of IO vpsDoes HP use KIO ?? onstat -g iov will mention KIO if it is using KIOIf it is then this may be a little high ? > >PHYSBUFF 64 # Physical log buffer size (Kbytes) > >LOGBUFF 64 # Logical log buffer size (Kbytes)> >LOGSMAX 12 # Maximum number of logical log files > >CLEANERS 2 # Number of buffer cleaner processes> > try setting this to the same as the number of LRU's Also I think there was once mention that it should never be a power of 2 so you may want to try 33 or 31 instead. Same applies for LRU's > > >SHMBASE 0x0

J.Cooper@MS03.dss.gsi.gov.uk wrote: > Tony Flaherty wrote: > > > > Ok, here goes my first EVER attempt at advising on someone elses onconfig, > > I'd go with any advice Art gives you ;o)) > > Good advice more comments below. I agree. Keep it up Tony. [SNIP] > > >NETTYPE ipcshm,240,120,CPU # Configure poll thread(s) for nettype> > These values seem to be way out. Whoa! How did I miss that! Unless you have 240 CPU VPs (not according to NUMCPUVPS) this will start up 240 NET VPS since there are not enough CPU VPs to hold 240 listener/poll threads and there should be a note in your online log to that effect at startup. And ALL of those 240 NET VPs are polling away at shared memory looking for work! Configure ONE shared memory poll thread per CPU VP as J. Cooper suggests below. > Art has written some very good articles explaining how this works. I read them with throughly and have forgotten it all :-(( Look on the archive or try something along the lines of > > NETTYPE ipcshm,3,80,CPU> > The number of CPU's may also have an effect if I remeber correctly. [SNIP] Art S. Kagel