Re: oninit use 95+%cpu

Informix 'trainers' that I've been around tend to know about odd quirks of the engine -- they hear about stuff from internal sources that we are rarely informed of. That said, I think the SERVERNUM suggestion is a crock that I would ignore and going resident is something of an extreme measure -- you'd have to go through a lengthy process of identifying exactly what would comprise resident memory (tables, indexes, etc) otherwise your memory map would be chaotic. What has been done to stat exactly what was taking place on the cpu that was under 95% load ? Was the offending VP(s) identified ? Could anyone isolate a thread ? What was happening with waiters, sleepers and ready threads ? Could you isolate a particular session, say an SQL stmt run amuck ? Try to determine exactly what Informix processes were taking place when the cpu was under 95% load. Use Onstat. have a nice day. vyao@dehavilland.ca wrote: > Hi, > > We have a production server which is running IDS 7.31uc2 on HP-UX 10.20. This > morning one oninit process use 95+% cpu and none of the users could do anything. > No any error could find in informix online log and unix syslog. > > At that time, there was a informix trainer happened to be on site and he suggest > changed two parameter: > 1)SERVERNUM from "101" to be "1". His explanation is that because when it was > 101, the shared memory was loosing contiguous space. He says that when the > default is 1 then contiguous space it retained. > 2) RESIDENT from NO(0) to YES(1). > > I am not sure about these two parameters. As my understanding, the value is not > important. It just need to be unique to the instance. And this machine, totally > 256MB physical memory and informix use 110MB. For me it is too tight to > resident. > > Anybody can tell me if these two parameters related to the problem or explain to > me the reason? > > Thanks in advance. > > Vivian > vyao@dehavilland.ca

richard palmer wrote: > Informix 'trainers' that I've been around tend to know about odd quirks > of the engine -- they hear about stuff from internal sources that we are Often true. > > rarely informed of. That said, I think the SERVERNUM suggestion is > a crock that I would ignore and going resident is something of an extreme > measure -- you'd have to go through a lengthy process of identifying > exactly what would comprise resident memory (tables, indexes, etc) > otherwise your memory map would be chaotic. > HUH? Setting RESIDENT to 1 is ALL one has to do. The engine allocates the 'resident' shared memory segment and requests that the OS make it permanently resident. The resident segment (class 'R' in the onstat -g seg report) contains basic data structures and the various caches: buffers, distributions cache headers, data dictionary cache headers, stored procedure cache headers. All other structures are in the virtual segment(s). > > What has been done to stat exactly what was taking place on the cpu > that was under 95% load ? Was the offending VP(s) identified ? Could > anyone isolate a thread ? What was happening with waiters, sleepers and > ready threads ? Could you isolate a particular session, say an SQL stmt > run amuck ? Try to determine exactly what Informix processes were > taking place when the cpu was under 95% load. Use Onstat. > > have a nice day. > > vyao@dehavilland.ca wrote: > > > Hi, > > > > We have a production server which is running IDS 7.31uc2 on HP-UX 10.20. This > > morning one oninit process use 95+% cpu and none of the users could do anything. > > No any error could find in informix online log and unix syslog. > > > > At that time, there was a informix trainer happened to be on site and he suggest > > changed two parameter: > > 1)SERVERNUM from "101" to be "1". His explanation is that because when it was > > 101, the shared memory was loosing contiguous space. He says that when the > > default is 1 then contiguous space it retained. > > 2) RESIDENT from NO(0) to YES(1). > > > > I am not sure about these two parameters. As my understanding, the value is not > > important. It just need to be unique to the instance. And this machine, totally > > 256MB physical memory and informix use 110MB. For me it is too tight to > > resident. > > > > Anybody can tell me if these two parameters related to the problem or explain to > > me the reason? > > > > Thanks in advance. > > > > Vivian > > vyao@dehavilland.ca