Re: KAIO and PDQ PRIORITY

Arun Shastry <arun@accentsoftware.com> offerred: +Alexander V.Didytch wrote: +> <snip> +> 10:53:47 dynamically allocated new shared memory segment (size 8388608) +> +> 10:53:50 dynamically allocated new shared memory segment (size 8388608) +> +> 10:53:53 KAIO: out of OS resources, errno = 11, pid = 4120 +> 10:53:53 KAIO: out of OS resources, errno = 11, pid = 4121 +> 10:53:58 KAIO: out of OS resources, errno = 11, pid = 4120 +> + +<snip> + +Check your release notes. Some OS's way of implementing Kernel AIO has +troubled Online (e.g. HP-UX 10.x). There's usually an environment variable +that needs to be set to bump up some default resource levels(e.g. on HP-UX +it is IFMX_HPKAIO_NUM_REQ, which defaults to 1000 but I have always +bumped it up to 2500). + +I really don't think you're running out of memory, unless you're sure about +it. There is a mention of KAIO resources & tuning the kernel in the release notes. However, given the context of the rest of Alexander's message, I'd say that it sounds like he hasn't tuned the other PDQ parameters correctly. KAIO running out of resources is one indication that you may be trying to do too many i/os in parallel. The additional shared memory segments being allocated is an indication that the quantum size for memory (DS_MAX_MEMORY/DS_MAX_QUERIES) may be set too high. Remember that the minimum amount of memory granted to a pdq query is a whole quantum; if the maximum number of queries is set too low, you will get an overly large quantum size, and the query will be granted more memory than it actually requested via PDQPRIORITY. Dave ** Dave Kosenko <davek@summitdata.com> ** Director of Training Services (732) 469-4070 ** Summit Data Group (an Informix Authorized Education Center) ** Find my advice useful? Let me teach you everything I know about ** Informix. Sign up for OFFICIAL Informix training at SDG. ** For details, see http://www.summitdata.com/training