shared memory and tempdb spaces

I'm pretty new to Informix and AIX and have a bit of a problem. The Informix log is showing the error "out of shared memory segments". From the other posts I've figured that we've hit the 2GB SHM limit and are probably going to move to the 64bit platform, but in the meantime I'd like to get this figured out. One change that I made just prior to getting this message was to enable 12 tempdb spaces where we originally had 4. I've reset it back to 4 to see if this indeed caused the problem and am tracking performance now. If this makes sense, is there a reason behind this? If this is not the issue, are there other places for me to look. Thanks. Here is the ontstat -g seg result when the error started occuring and our onconfig file (with the tempdbs back to 4, and that being the only change). The ipcs -m command showed 19 total memory segments 6 of which were the Informix segments. Informix Dynamic Server Version 7.31.UD3 -- On-Line -- Up 22:57:57 -- 266790 4 Kbytes Segment Summary: id key addr size ovhd class blkused blkfree 524288 1381451777 30000000 584450048 28620 R 71337 7 19791890 1381451778 60000000 1073741824 16988 V 129439 1633 194641932 1381451779 a0000000 268435456 4700 V 31753 1015 9175044 1381451780 b0000000 268435456 4700 V 31625 1143 2228231 1381451781 c0000000 268435456 4700 V 30520 2248 43122694 1381451782 e0000000 268435456 4700 V 25966 6802 Total: - - 2731933696 - - 320640 12848 ******************************************************************************************* # Root Dbspace Configuration ROOTNAME rootdbs # Root dbspace name ROOTPATH /Medic/db/ifx1/rootdbs # Path for device containing root dbspace ROOTOFFSET 4 # Offset of root dbspace into device (Kbytes) ROOTSIZE 655356 # 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 physlog # Location (dbspace) of physical log PHYSFILE 128414 # Physical log file size (Kbytes) # Logical Log Configuration LOGFILES 208 # Number of logical log files LOGSIZE 20000 # Logical log size (Kbytes) # Diagnostics MSGPATH /Medic/db/ifx1/informix.log # System message log file path CONSOLE /Medic/db/ifx1/console.log # System console message path ALARMPROGRAM /Medic/APPS/Informix73/etc/no_log.sh # Alarm program path SYSALARMPROGRAM /Medic/APPS/Informix73/etc/evidence.sh # System Alarm program path TBLSPACE_STATS 1 # System Archive Tape Device TAPEDEV /dev/rmt0.1 # Tape device path TAPEBLK 1024 # Tape block size (Kbytes) TAPESIZE 195000000 # Maximum amount of data to put on tape (Kbytes) # Log Archive Tape Device LTAPEDEV /dev/null # Log tape device path LTAPEBLK 1024 # Log tape block size (Kbytes) LTAPESIZE 8900000 # 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 DynamicServer instance DBSERVERNAME ifx1 # Name of default database server DBSERVERALIASES ifx1_tcp1 # List of alternate dbservernames NETTYPE soctcp,8,100,NET 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 8 # Number of user (cpu) vps SINGLE_CPU_VP 0 # If non-zero, limit number of cpu vpsto one NOAGE 1 # Process aging AFF_SPROC 0 # Affinity start processor AFF_NPROCS 0 # Affinity number of processors # Shared Memory Parameters LOCKS 1000000 # Maximum number of locks BUFFERS 126000 # Maximum number of shared buffers NUMAIOVPS 1 # Number of IO vps PHYSBUFF 64 # Physical log buffer size (Kbytes) LOGBUFF 64 # Logical log buffer size (Kbytes)LOGSMAX 214 # Maximum number of logical log files CLEANERS 48 # Number of buffer cleaner processes SHMBASE 0x30000000 # Shared memory base address SHMVIRTSIZE 1048576 # initial virtual shared memory segmentsize SHMADD 262144 # Size of new shared memory segments (Kbytes) SHMTOTAL 0 # Total shared memory (Kbytes). 0=>unlimited CKPTINTVL 300 # Check point interval (in sec) LRUS 48 # Number of LRU queues LRU_MAX_DIRTY 10 # LRU percent dirty begin cleaninglimit LRU_MIN_DIRTY 5 # LRU percent dirty end cleaning limit LTXHWM 50 # Long transaction high water markpercentage LTXEHWM 60 # Long transaction high water mark (exclusive) TXTIMEOUT 0x12c # 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 /Medic/APPS/Informix73/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 (Kb ytes)CDR_LOGDELTA 30

If you are on 32 bit AIX (version information essential) and you have 2.7Gb shared memory for Informix plus 13 other shared memory segments, you have probably run out of shared memory on your server. Your application is asking Informix for resources, Informix is asking the OS for more shared memory and the OS is returning that there is no more available. MW -----Original Message----- From: informix-list-bounces@iiug.org [mailto:informix-list-bounces@iiug.org] On Behalf Of DLC Sent: Wednesday, 22 November 2006 7:42 a.m. To: informix-list@iiug.org Subject: shared memory and tempdb spaces I'm pretty new to Informix and AIX and have a bit of a problem. The Informix log is showing the error "out of shared memory segments". From the other posts I've figured that we've hit the 2GB SHM limit and are probably going to move to the 64bit platform, but in the meantime I'd like to get this figured out. One change that I made just prior to getting this message was to enable 12 tempdb spaces where we originally had 4. I've reset it back to 4 to see if this indeed caused the problem and am tracking performance now. If this makes sense, is there a reason behind this? If this is not the issue, are there other places for me to look. Thanks. Here is the ontstat -g seg result when the error started occuring and our onconfig file (with the tempdbs back to 4, and that being the only change). The ipcs -m command showed 19 total memory segments 6 of which were the Informix segments. Informix Dynamic Server Version 7.31.UD3 -- On-Line -- Up 22:57:57 -- 266790 4 Kbytes Segment Summary: id key addr size ovhd class blkused blkfree 524288 1381451777 30000000 584450048 28620 R 71337 7 19791890 1381451778 60000000 1073741824 16988 V 129439 1633 194641932 1381451779 a0000000 268435456 4700 V 31753 1015 9175044 1381451780 b0000000 268435456 4700 V 31625 1143 2228231 1381451781 c0000000 268435456 4700 V 30520 2248 43122694 1381451782 e0000000 268435456 4700 V 25966 6802 Total: - - 2731933696 - - 320640 12848 **************************************************************************** *************** # Root Dbspace Configuration ROOTNAME rootdbs # Root dbspace name ROOTPATH /Medic/db/ifx1/rootdbs # Path for device containing root dbspace ROOTOFFSET 4 # Offset of root dbspace into device (Kbytes) ROOTSIZE 655356 # 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 physlog # Location (dbspace) of physical log PHYSFILE 128414 # Physical log file size (Kbytes) # Logical Log Configuration LOGFILES 208 # Number of logical log files LOGSIZE 20000 # Logical log size (Kbytes) # Diagnostics MSGPATH /Medic/db/ifx1/informix.log # System message log file path CONSOLE /Medic/db/ifx1/console.log # System console message path ALARMPROGRAM /Medic/APPS/Informix73/etc/no_log.sh # Alarm program path SYSALARMPROGRAM /Medic/APPS/Informix73/etc/evidence.sh # System Alarm program path TBLSPACE_STATS 1 # System Archive Tape Device TAPEDEV /dev/rmt0.1 # Tape device path TAPEBLK 1024 # Tape block size (Kbytes) TAPESIZE 195000000 # Maximum amount of data to put on tape (Kbytes) # Log Archive Tape Device LTAPEDEV /dev/null # Log tape device path LTAPEBLK 1024 # Log tape block size (Kbytes) LTAPESIZE 8900000 # 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 DynamicServer instance DBSERVERNAME ifx1 # Name of default database server DBSERVERALIASES ifx1_tcp1 # List of alternate dbservernames NETTYPE soctcp,8,100,NET 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 8 # Number of user (cpu) vps SINGLE_CPU_VP 0 # If non-zero, limit number of cpu vpsto one NOAGE 1 # Process aging AFF_SPROC 0 # Affinity start processor AFF_NPROCS 0 # Affinity number of processors # Shared Memory Parameters LOCKS 1000000 # Maximum number of locks BUFFERS 126000 # Maximum number of shared buffers NUMAIOVPS 1 # Number of IO vps PHYSBUFF 64 # Physical log buffer size (Kbytes) LOGBUFF 64 # Logical log buffer size (Kbytes)LOGSMAX 214 # Maximum number of logical log files CLEANERS 48 # Number of buffer cleaner processes SHMBASE 0x30000000 # Shared memory base address SHMVIRTSIZE 1048576 # initial virtual shared memory segmentsize SHMADD 262144 # Size of new shared memory segments (Kbytes) SHMTOTAL 0 # Total shared memory (Kbytes). 0=>unlimited CKPTINTVL 300 # Check point interval (in sec) LRUS 48 # Number of LRU queues LRU_MAX_DIRTY 10 # LRU percent dirty begin cleaninglimit LRU_MIN_DIRTY 5 # LRU percent dirty end cleaning limit LTXHWM 50 # Long transaction high water markpercentage LTXEHWM 60 # Long transaction high water mark (exclusive) TXTIMEOUT 0x12c # 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

Looks like reducing the number of tempdb spaces did the trick for now. We are running on AIX 5.2 with 8 processors and 16GB of memory. So, I'd really like to know more about the relationship between these tempdb spaces and shared memory. Thanks. DC > _______________________________________________ > Informix-list mailing list > Informix-list@iiug.org > http://www.iiug.org/mailman/listinfo/informix-list