dynamically allocated new shared memory segment - What is this?

We had a pause in our Informix 7.3 system today around 5:00pm. The system just 'froze' for almost a minute. Is there something that needs to be tuned? This is the log during that period: Thanks Gary Quiring 16:44:50 Logical Log 23611 Complete. 16:48:13 Logical Log 23612 Complete. 16:49:25 Checkpoint Completed: duration was 12 seconds. 16:52:56 Logical Log 23613 Complete. 16:54:41 Checkpoint Completed: duration was 13 seconds. 16:55:05 dynamically allocated new shared memory segment (size 33554432) 16:55:44 dynamically allocated new shared memory segment (size 33554432) 16:58:20 Logical Log 23614 Complete. 17:00:17 Checkpoint Completed: duration was 32 seconds. 17:04:02 Logical Log 23615 Complete. 17:05:33 Checkpoint Completed: duration was 12 seconds. 17:10:42 Checkpoint Completed: duration was 7 seconds. 17:13:00 Logical Log 23616 Complete. onconfig file: ROOTNAME rootdbs # Root dbspace name ROOTPATH /dev/lrootdbs # Path for device containing rootdbspace ROOTOFFSET 0 # Offset of root dbspace into device (Kbytes) ROOTSIZE 200000 # 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 plogdbs PHYSFILE 100000 # Logical Log Configuration LOGFILES 100 # Number of logical log files LOGSIZE 2500 # Logical log size (Kbytes) # Diagnostics MSGPATH /u/ifmx/online.log # System message log file path CONSOLE /dev/console # System console message path ALARMPROGRAM # /u/ifmx/etc/log_full.sh # Alarm program pathSYSALARMPROGRAM /u/ifmx/etc/evidence.sh # System Alarm program path TBLSPACE_STATS 1 # Optical STAGEBLOB # Informix Dynamic Server/Optical staging area # System Configuration SERVERNUM 0 # Unique id corresponding to a DynamicServer in stance DBSERVERNAME emco1_shm # Name of default database server DBSERVERALIASES emco1_net # List of alternate dbservernames NETTYPE ipcshm,2,200,CPU # Configure poll thread(s) for sharedmem NETTYPE tlitcp,2,130,NET # Configure poll thread(s) fornetwork DEADLOCK_TIMEOUT 60 # Max time to wait of lock indistributed env. RESIDENT 1 # Forced residency flag (Yes = 1, No = 0) MULTIPROCESSOR 1 # 0 for single-processor, 1 formulti-processor NUMCPUVPS 3 # 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 300000 # Maximum number of shared buffers NUMAIOVPS # Number of IO vps PHYSBUFF 32 # Physical log buffer size (Kbytes) LOGBUFF 32 # Logical log buffer size (Kbytes)LOGSMAX 200 # Maximum number of logical log files CLEANERS 20 # Number of buffer cleaner processes SHMBASE 0x82000000 # Shared memory base address SHMVIRTSIZE 131072 # initial virtual shared memorysegment size SHMADD 32768 # Size of new shared memory segments (Kbytes) SHMTOTAL 0 # Total shared memory (Kbytes). 0=>unlimited CKPTINTVL 300 # Check point interval (in sec) LRUS 20 # Number of LRU queues LRU_MAX_DIRTY 3 # LRU percent dirty begin cleaninglimit LRU_MIN_DIRTY 1 # LRU percent dirty end cleaning limit LTXHWM 40 # Long transaction high water markpercentage LTXEHWM 50 # Long transaction high water mark (exclusive) TXTIMEOUT 0x12c # Transaction timeout (in sec) STACKSIZE 32 # Stack size (Kbytes) # 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 /u/ifmx/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) # 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 # Informix Storage Manager variables ISM_DATA_POOL ISMData # If the data pool name is changed, be sure to # update $INFORMIXDIR/bin/onbar. Change to # ism_catalog -create_bootstrap -pool <new name> ISM_LOG_POOL ISMLogs # Read Ahead Variables RA_PAGES # Number of pages to attempt to readahead RA_THRESHOLD # Number of pages left before nextgroup DBSPACETEMP temp1dbs:temp2dbs # Default temp dbspaces # DUMP*: # The following parameters control the type of diagnostics information which # is preserved when an unanticipated error condition (assertion failure) occurs # during Dynamic Server operations. # For DUMPSHMEM, DUMPGCORE and DUMPCORE 1 means Yes, 0 means No. DUMPDIR /tmp # Preserve diagnostics in thisdirectory DUMPSHMEM 0 # Dump a copy of shared memory DUMPGCORE 0 # Dump a core image using 'gcore' DUMPCORE 0 # Dump a core image (Warning:thisaborts Dynamic Server) DUMPCNT 1 # Number of shared memory or gcoredumps for # a single user's session FILLFACTOR 90 # Fill factor for building indexes # method for Dynamic Server to use when determining current time USEOSTIME 0 # 0: use internal time(fast), 1: get time from O@@

FWIW, you can increase your SHMVIRTSIZE to 196608 ( 131072 + 32768 + 32768 ) to prevent the instance from asking for more memory the next time this problem occurs. You'll need to bounce your instance for this to take effect. The instance had to allocate two more shared memory segments at 5:00. The next time have a SHMVIRTSIZE that is big enough ( SHMVIRTSIZE + SHMADD + SHMADD ). Hope this helps. Brice Gary Quiring wrote: > We had a pause in our Informix 7.3 system today around 5:00pm. The > system just 'froze' for almost a minute. Is there something that > needs to be tuned? This is the log during that period: > > Thanks > > Gary Quiring > > 16:44:50 Logical Log 23611 Complete. > 16:48:13 Logical Log 23612 Complete. > 16:49:25 Checkpoint Completed: duration was 12 seconds. > 16:52:56 Logical Log 23613 Complete. > 16:54:41 Checkpoint Completed: duration was 13 seconds. > 16:55:05 dynamically allocated new shared memory segment (size > 33554432) > > 16:55:44 dynamically allocated new shared memory segment (size > 33554432) > > 16:58:20 Logical Log 23614 Complete. > 17:00:17 Checkpoint Completed: duration was 32 seconds. > 17:04:02 Logical Log 23615 Complete. > 17:05:33 Checkpoint Completed: duration was 12 seconds. > 17:10:42 Checkpoint Completed: duration was 7 seconds. > 17:13:00 Logical Log 23616 Complete.> > onconfig file: > > ROOTNAME rootdbs # Root dbspace name > ROOTPATH /dev/lrootdbs # Path for device containing root> dbspace > ROOTOFFSET 0 # Offset of root dbspace into device > (Kbytes) > ROOTSIZE 200000 # 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 plogdbs > PHYSFILE 100000> > # Logical Log Configuration > > LOGFILES 100 # Number of logical log files > LOGSIZE 2500 # Logical log size (Kbytes)> > # Diagnostics > > MSGPATH /u/ifmx/online.log # System message log file path > CONSOLE /dev/console # System console message path > ALARMPROGRAM # /u/ifmx/etc/log_full.sh # Alarm program path> SYSALARMPROGRAM /u/ifmx/etc/evidence.sh # System Alarm program path > TBLSPACE_STATS 1> > # Optical > > STAGEBLOB # Informix Dynamic Server/Optical > staging area > > # System Configuration > > SERVERNUM 0 # Unique id corresponding to a Dynamic> Server in > stance > DBSERVERNAME emco1_shm # Name of default database server > DBSERVERALIASES emco1_net # List of alternate dbservernames > NETTYPE ipcshm,2,200,CPU # Configure poll thread(s) for shared> mem > NETTYPE tlitcp,2,130,NET # Configure poll thread(s) for> network > DEADLOCK_TIMEOUT 60 # Max time to wait of lock in> distributed env. > RESIDENT 1 # Forced residency flag (Yes = 1, No = > 0) > > MULTIPROCESSOR 1 # 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 > > 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 300000 # Maximum number of shared buffers > NUMAIOVPS # Number of IO vps > PHYSBUFF 32 # Physical log buffer size (Kbytes) > LOGBUFF 32 # Logical log buffer size (Kbytes)> LOGSMAX 200 # Maximum number of logical log files > CLEANERS 20 # Number of buffer cleaner processes > SHMBASE 0x82000000 # Shared memory base address > SHMVIRTSIZE 131072 # initial virtual shared memory> segment size > SHMADD 32768 # Size of new shared memory segments > (Kbytes) > SHMTOTAL 0 # Total shared memory (Kbytes). > 0=>unlimited > CKPTINTVL 300 # Check point interval (in sec) > LRUS 20 # Number of LRU queues > LRU_MAX_DIRTY 3 # LRU percent dirty begin cleaning> limit > LRU_MIN_DIRTY 1 # LRU percent dirty end cleaning limit > LTXHWM 40 # Long transaction high water mark> percentage > LTXEHWM 50 # Long transaction high water mark > (exclusive) > TXTIMEOUT 0x12c # Transaction timeout (in sec) > STACKSIZE 32 # Stack size (Kbytes)> > # 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 /u/ifmx/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)> > # 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> > # Informix Storage Manager variables > ISM_DATA_POOL ISMData # If the data pool name is changed, be > sure to > # update $INFORMIXDIR/bin/onbar. > Change to > # ism_catalog -create_bootstrap -pool > <new name> > > ISM_LOG_POOL ISMLogs > > # Read Ahead Variables > RA_PAGES # Number of pages to attempt to read> ahead > RA_THRESHOLD # Number of pages left before next> group > > DBSPACETEMP temp1dbs:temp2dbs # Default temp dbspaces > > # DUMP*: > # The following parameters control the type of diagnostics information > which > # is preserved when an unanticipated error condition (assertion > failure) occurs > # during Dynamic Server