Re: long checkpoints
I'm just curious: What's the row size of the table that's getting all
the inserts? And how does that compare to your system's page size?
Apostrof wrote:
> hi,
> i have some problem with the long running checkpoints in IDS 7.31.UD8
> on HP/UX.
> every day a batch utility making hig volume of insert and updates. and
> this batch works about 5-10 minutes(checkpoint times included).
> during this batch load one or two (long) checkpoints occur.
> (unfortunately blocking checkpoints)
>
> 17:32:53 Checkpoint Completed: duration was 160 seconds.
> 17:32:53 Checkpoint loguniq 1250, logpos 0x1842484
> 17:38:59 Checkpoint Completed: duration was 155 seconds.
> 17:38:59 Checkpoint loguniq 1253, logpos 0x8fa098>
> some of the onconfig parameters are
>
> PHYSDBS rootdbs # Location (dbspace) of physical log
> PHYSFILE 100000 # Physical log file size (Kbytes)
>
> LOGFILES 40 # Number of logical log files
> LOGSIZE 20000 # Logical log size (Kbytes)> LOGSMAX 50
>
> LOCKS 150000 # Maximum number of locks
> BUFFERS 200000 # Maximum number of shared buffers
> NUMAIOVPS # Number of IO vps
> PHYSBUFF 64 # Physical log buffer size (Kbytes)
> LOGBUFF 64 # Logical log buffer size (Kbytes)
> CLEANERS 50 # Number of buffer cleaner processes
> SHMBASE 0x0 # Shared memory base address
> SHMVIRTSIZE 64000 # initial virtual shared memory> segment size
> SHMADD 32000 # Size of new shared memory segments
> (Kbytes)
> SHMTOTAL 0 # Total shared memory (Kbytes).
> 0=>unlimited
> CKPTINTVL 200 # Check point interval (in sec)
> LRUS 50 # Number of LRU queues
> LRU_MAX_DIRTY 60 # LRU percent dirty begin cleaning> limit
> LRU_MIN_DIRTY 50 # LRU percent dirty end cleaning limit
> LTXHWM 50 # Long transaction high water mark> percentage
> LTXEHWM 60 # Long transaction high water mark
> (exclusive)
> TXTIMEOUT 0x12c # Transaction timeout (in sec)
> STACKSIZE 64 # Stack size (Kbytes)>
> when checkpoint starts i look at onstat -F output and see one or two
> lines with state C. the chunk writes takes much of the checkpoint
> time.
> i changed the LRU_MAX_DIRTY:10, LRU_MIN_DIRTY:5 and try the batch
> again. but this time due to LRU writes
> the batch utility gets slower and finishes its job about at 20minutes.
> i've read in some notes that LRU writes is worse than chunk writes.
> so what can i do to make this batch process faster and shorten
> checkpoint times?
> thanks
>
> Abdullah
>