Re: KAIO Question [8766]

Art, I did have our Techs configure one raw dbspace/chunk that I added within the instance to see if that made a difference, but it did not. -John -----Original Message----- >From: "ART KAGEL, BLOOMBERG/ 731 LEXIN" <kagel@bloomberg.net> >Sent: Mar 30, 2007 7:56 AM >To: ids@iiug.org >Subject: Re: KAIO Question [8766] > >No, KAIOON is only needed on HPUX platforms (IB there's some difficulty >detecting whether the OS KAIO services are online or not) KAIO is the default >for RAW chunks on all other platforms. Are any of your chunks in that instance >RAW? If not, KAIO will be disabled. > >Art S. Kagel >----- Original Message ----- >From: John <ids@iiug.org> >At: 3/30 8:53:45 > >Art, > >I agree, and having checked for the env variable "KAIO_OFF=1", made sure it >was removed from the .profile, and confirmed I do not see it set anywhere >else. I have bounced the engine, and confirmed it does not exist, but still do >not see the KIO thread. Do I need to do something to turn it back on (i.e., >KAIOON=1000 or KAIOOFF=0)? > >-John > >-----Original Message----- >>From: "ART KAGEL, BLOOMBERG/ 731 LEXIN" <kagel@bloomberg.net> >>Sent: Mar 29, 2007 4:54 PM >>To: ids@iiug.org >>Subject: Re: KAIO Question [8763] >> >>IDS AIO VPs do NOT use OS Asynch IO facilities, they simulate asynch IO for >>cooked chunks. If you use RAW chunks there should be only a few aio vps >>configures and onstat -g iov will show one kio thread for each CPU VP. The >>only >>way you would not see KIO threads if all of your chunks are RAW is if you >>disabled KAIO using the environment variable KAIO_OFF=1 in the server's >>startup >>environment. >> >>Art S. Kagel >>----- Original Message ----- >>From: John <ids@iiug.org> >>At: 3/29 17:45:04 >> >>To any AIX / IDS gurus out there, >> >>Background: >> >>We are running IDS 10.00 FC4 on AIX 5.2 TL8. We have been having some AIO >>issues with two boxes (each is a 390 with 8 cpu's), one dev and one prod. We >>tuned the DEV box with min and max AIX AIO 5, and 180 respectively, and it is >>running fine, and seemingly wide open. There are actually over 360 IO threads >>running, but only a dozen or so showing that they are clocking any CPU time. >>This machine, with (all cpu and aio) noage activated, is seemingly screaming >>along. >>PROD is set with min max 1 and 180 respectively (the machine notes show that >>it should be set to MIN =1) and it only has one thread running, and it does >>not even show it clocking any CPU. Although on the database side there are >140 >>aio vp's (threads), it appears that something is holding AIX from spawning >any >>more (Unix)AIO processes, and it is seemingly creating a bottleneck. This >>database also has noage activated on all cpu and aio vp's, but the machine >>seems to not be spawning off any of the seemingly needed (Unix)AIO procs. The >>tech does not want to increase the prod config based on the machine notes. >>The boxes, prod and dev, have 8 and 128, and 4 and 128 cpu and aio vp's >>configured, respectively, again, all noage. Dev is a shared box and only has >4 >>cpuvp's. >>Tech has showed that although I/O should be in the 80mb per second, we are >>using but a small fraction of that. >> >>Questions: >>A. Does setting the AIX MIN aio value to 1 disable the spawning of additional >>threads/processes as needed?, and does setting it at say "5" and bouncing the >>machine enable and open it up to AIO thread volume increases as AIX deems >>appropriate? According to the aforementioned scenario, it certainly appears >>to, but if I could get an explanation of exactly why/how it works...??? >> >>B. On AIX, in regards to the PSE driver, the machine notes for AIX 5.2 and >5.3 >>say it should be loaded via "/usr/bin/strload" (generic configuration) and >>that it works hand in hand with enabling KAIO. Is there a preferred way as a >>DBA to ensure that it is activated on both of our servers and configured >>properly? I have read all the documentation I can find, but it does not >answer >>these specific questions. Does the NETTYPE have to reflect socstr in order to >>work? >> >>C. We have been advised through documentation available on the IBM website >>that we should enable KAIO, but have been unable to get it to come on/with >the >>cooked files, even when building the DB in raw, and have been unable to find >>the necessary settings to config to get it to activate. >> >>I have requested to turn KAIO on for this server. They have cooked >>filesystems, and yes, I would alwys use KAIO with raw, but there has been >>documentation that shows that you can still use it with KAIO enabled and get >>almost raw performance. >> >>Here is an excerpt from the onconfig file. You can see we have discontinued >>using processor affinity until we can get the I/O issue resolved, and scaled >>the aiovp's way back. We have reduced the number of aiovps until we can get >>the ones that are present to work. This is a data warehouse database with >>several fragmented tables, of about 700GB in size. >> >>....... >>SERVERNUM 1 # Unique id corresponding to a OnLine instance >>DBSERVERNAME nmprdbdev_shm # Name of default database server>>DBSERVERALIASES nmprdbdev_tcp,nmprdbdev_tcp2 # List of alternate >dbservernames >>SINGLE_CPU_VP 0 # Set to 1 if VPCLASS cpu, num=1 >>MULTIPROCESSOR 1 # Set to 1 if VPCLASS cpu, num>1>> >>#VPCLASS cpu,num=4,aff=4-7,noage # Number of cpu virtual processors (vps) >>#VPCLASS aio,num=8,aff=0-7,noage # Number of IO vps >> >>VPCLASS cpu,num=8 # Number of cpu virtual processors (vps) >>VPCLASS aio,num=8 # Number of IO vps (at least 1 per XPSdbspace >> >>NETTYPE ipcshm,1,250,CPU # Poll thread type,no. of cpu's,max users,class >>NETTYPE soctcp,4,250,NET # Poll thread type,no. of cpu's,max users,class >>........>> >>Thanks, >> >>John >> >> > > >>******************************************************************************* > >>Forum Note: Use "Reply" to post a response in the discussion forum. >> >> > > >>******************************************************************************* > >> Forum Note: Use "Reply" to post a response in the discussion forum. >> > > >******************************************************************************* >Forum Note: Use "Reply" to post a response in the discussion forum. > > >******************************************************************************* > Forum Note: Use "Reply" to post a response in the discussion forum. >