Informix Dynamic Server onstat option

Onstat-D
INFORMIX-OnLineVersion7.22.UC1--On-Line--Up00:00:38--423064Kbytes
Dbspaces
addressnumberflagsfchunknchunksflagsownername
ad5c1001111Ninformixrootdbs
ad5dc282121Ninformixdbs7
ad5dc983131Ninformixdbs8
3active,2047maximum
Chunks
addresschk/dbsoffsetpageRdpageWrpathname
ad5c17011501259289/dev/pa11
ad5c63822501111/dev/pa12
ad5c710335030/dev/pa13
3active,2047maximum

Monitor the number of page reads and Page writes in the "Pagerd" and "pagewr" columns, so that you can check the balance of each chunk access. Remember that there may be multiple chunk on one device.

Onstat-F
InformixDynamicServer2000Version9.21.FC1--On-Line--Up18:05:32--s
FgWritesLRUWritesChunkWrites
0602010355973
addressflusherstatedata
c0000000ba33e8280I0=0X0
c0000000ba33f0281I0=0X0
c0000000ba33f8282I0=0X0
c0000000ba3400283I0=0X0
states:ExitIdleChunkLru

Monitor the kinds of writes that occur on the system. Front-desk Writing (fgwrites) should be limited, LRU write and chunk will vary depending on the system.

OLTP systems should reduce LRU writes, but there are always chunk writes, but LRU writes reduce the duration of checkpoints. In the DSS system, chunk writing should be greatly improved, but some LRU writing will still occur to limit the foreground writing. At checkpoint time, monitor the page cleaner (refresher) to make sure that they are all busy with chunk writing.

onstat-l
InformixDynamicServer2000Version9.21.FC1--On-Line--Up18:07:45--4
046800Kbytes
PhysicalLogging
Bufferbufusedbufsizenumpagesnumwritspages/io
P-245220003647872881266.62
phybeginphysizephyposphyused%used
1021595000003211664800.10
LogicalLogging
Bufferbufusedbufsizenumrecsnumpagesnumwritsrecs/pagespages/io
L-23100011052069515302241221.4213.6
SubsystemnumrecsLogSpaceused
OLDRSAM110520691038267280
addressnumberflagsuniqidbeginsizeused%used
c00000001807d4c04U-B----67243000352500025000100.00
c00000001807d4e05U-B----67253061dd2500025000100.00
c00000001807d5006U-B----672630c3852500025000100.00
c00000001807d5207U-B----672731252d2500025000100.00
c00000001807d5408U-B----67283186d52500025000100.00
c00000001807d5609U-B----672931e87d2500025000100.00

Monitoring the use of physical log buffers and observing the bufsize and Pages/io columns in the first row of output, such as Pages/io divided by bufsize of approximately 75%, can be used to determine the efficiency of the buffer. If less than 75%, the physical log buffer may be too large. If the ratio is greater than 90%. The physical buffer is too small.

The

uses the same method to monitor the use of the logical log buffers. However, if you use no buffer log, the buffer refresh depends on the size of the transaction, not the use of the buffer, which can always be true. If most transactions are smaller than the logical log buffer page, this ratio may always be off, keeping the logical buffer log at its default value. The bit physical log file should be monitored when the checkpoint occurs to determine whether the ratio is close to 75%. A well tuned physical log file is almost full when the checkpoint occurs, wasting disk space if the file is not full. You should also monitor the logical log files to make sure they are backed up. Using the Sysmaster database, you can determine which logical log file is idle, look for the rows of min (Tx_logunip) >0 in the Sytrans table, and find the last logical log file that contains the open transaction.

onstat-m
InformixDynamicServer2000Version9.21.FC1--On-Line--Up18:07:45--4
MessageLogFile:/informix/online_cqys.log
15:04:02Checkpointloguniq6739,logpos0x884360
15:09:06FuzzyCheckpointCompleted:durationwas0seconds,12066buffersno.
15:09:06Checkpointloguniq6739,logpos0x1719768
15:14:11FuzzyCheckpointCompleted:durationwas2seconds,3236buffersnot.
15:14:11Checkpointloguniq6739,logpos0x36aa018
15:19:14FuzzyCheckpointCompleted:durationwas0seconds,4645buffersnot.
15:19:14Checkpointloguniq6739,logpos0x39d8454
15:24:17FuzzyCheckpointCompleted:durationwas0seconds,5692buffersnot.
15:24:17Checkpointloguniq6739,logpos0x3bfb06c
15:29:20FuzzyCheckpointCompleted:durationwas0seconds,6731buffersnot.
15:29:20Checkpointloguniq6739,logpos0x3df959c
15:34:23FuzzyCheckpointCompleted:durationwas0seconds,7886buffersnot.
15:34:23Checkpointloguniq6739,logpos0x403f258