Can I bring informix up/down from another computer
Dan asked whether an IDS 11.70 instance on AIX 7.2 could be shut down remotely, since OS memory exhaustion sometimes prevented forking a local process to run onmode. Fernando answered that a graceful shutdown can be triggered over a connection with EXECUTE FUNCTION sysadmin:task('onmode','k'), though there's no equivalent way to start the engine remotely. Discussion then turned to the underlying memory problem: suggestions included reviewing RESIDENT/SHMTOTAL settings and, since Dan believed large file reads were the cause, tuning AIX's file system cache parameters (which favour file caching by default) with help from an AIX specialist. The OS issue itself was left unresolved.
Auto-generated by DrWatson from the posts below — may be imperfect; read the full thread.
Hey Folks, IDS 11.70.FC8 AIX 7.2 I was just wondering if there is a way to bring Informix down from another computer? We have had incidents where memory issues prevented us from forking a process and it would be nice to shut down gracefully. thanx, dan
Shutdown yes, assuming the instance is running and answering requests:
Execute function sysadmin:task('onmode', 'k');
Please test...
This obviously doesn't work to start it.... we used to supply a daemon that
would allow us to start it from OAT.... not sure if it still is the case.
Bit, IMHO you're missing the point... you have to fix the memory issues...
On Oct 26, 2017 18:50, "DAN MUELLER" <ddmueller@west.com> wrote:
> Hey Folks,
>
> IDS 11.70.FC8
> AIX 7.2
>
> I was just wondering if there is a way to bring Informix down from another
> computer? We have had incidents where memory issues prevented us from
> forking
> a process and it would be nice to shut down gracefully.
>
> thanx,
> dan
>
>
> ************************************************************
> *******************
> Forum Note: Use "Reply" to post a response in the discussion forum.
>
>
Also: RESIDENT -1 ? Could be contributing to 'memory issues', and shouldn't be required on AIX.
I didn't want to elaborate too much on this. I tried to answer the question only... But "memory issues" are either a bug (memory leak) which must be fixed, so a PMR must be opened, or bad engine / OS configuration (don't take this as criticism). Either case needs investigation. Informix should not "eat" that much memory that would prevent a login on the machine. And it will only happen if SHMTOTAL is set to "0". I usually recommend against this setting, precisely because a runaway engine can "eat" all the system memory and affect other instances on the same system or the system itself. Naturally if a customer only has one instance on the machine this is not as critical. Now... The big problem in setting it to something differently than "0" is that the parameter is not dynamic! I find it hard to understand why we can't (yet) change it dynamically at least to increase it. I could imagine issues on decreasing it (if we try to lower it beyond the current instance usage. But you already know me... I always think some code changes are easy... probably because I don't mess with the code myself, and because I don't have a tight agenda of features and important customers pressuring with features I consider less important :) In other words, speaking is easy, doing it might me slightly harder :) Regarding RESIDENT set to -1... specially for AIX... again I think it's kind of a myth. I understand why we started to recommend this, and I know we had issues with KAIO ( http://www-01.ibm.com/support/docview.wss?uid=swg1IC76872) but again... It's mainly a misconfiguration and some "dumb"(?) AIX defaults (pinnable memory). Naturally, considering the seriousness of the possible effects, -1 is the safe and simple recommendation. Regards. On Fri, Oct 27, 2017 at 8:55 AM, Andreas Legner1 <Andreas.Legner1@de.ibm.com > wrote: > Also: RESIDENT -1 ? > > Could be contributing to 'memory issues', and shouldn't be required on AIX. > > > ************************************************************ > ******************* > Forum Note: Use "Reply" to post a response in the discussion forum. > > -- Fernando Nunes Portugal http://informix-technology.blogspot.com My email works... but I don't check it frequently...
Fernando, Our "memory issue" in Not Informix related. It comes from the OS. I have a suspicion that opening a very large file loads the entire file into memory and that is causing the issues. Unfortunately, we are not close to our sysadmins and we have not been able to prove/disprove that out. PMRs have been opened and closed w/o much ado. We continue to try to get this one figured out but I have not seen Informix grow past SHMTOTAL (not set to 0). Thank you so much for the followup though. I do appreciate all the help I can get. Dan -----Original Message----- From: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org] On Behalf Of Fernando Nunes Sent: Friday, October 27, 2017 5:33 AM To: ids@iiug.org Subject: Re: Can I bring informix up/down from another .... [40108] I didn't want to elaborate too much on this. I tried to answer the question only... But "memory issues" are either a bug (memory leak) which must be fixed, so a PMR must be opened, or bad engine / OS configuration (don't take this as criticism). Either case needs investigation. Informix should not "eat" that much memory that would prevent a login on the machine. And it will only happen if SHMTOTAL is set to "0". I usually recommend against this setting, precisely because a runaway engine can "eat" all the system memory and affect other instances on the same system or the system itself. Naturally if a customer only has one instance on the machine this is not as critical. Now... The big problem in setting it to something differently than "0" is that the parameter is not dynamic! I find it hard to understand why we can't (yet) change it dynamically at least to increase it. I could imagine issues on decreasing it (if we try to lower it beyond the current instance usage. But you already know me... I always think some code changes are easy... probably because I don't mess with the code myself, and because I don't have a tight agenda of features and important customers pressuring with features I consider less important :) In other words, speaking is easy, doing it might me slightly harder :) Regarding RESIDENT set to -1... specially for AIX... again I think it's kind of a myth. I understand why we started to recommend this, and I know we had issues with KAIO ( http://www-01.ibm.com/support/docview.wss?uid=swg1IC76872) but again... It's mainly a misconfiguration and some "dumb"(?) AIX defaults (pinnable memory). Naturally, considering the seriousness of the possible effects, -1 is the safe and simple recommendation. Regards. On Fri, Oct 27, 2017 at 8:55 AM, Andreas Legner1 <Andreas.Legner1@de.ibm.com > wrote: > Also: RESIDENT -1 ? > > Could be contributing to 'memory issues', and shouldn't be required on AIX. > > > ************************************************************ > ******************* > Forum Note: Use "Reply" to post a response in the discussion forum. > > -- Fernando Nunes Portugal http://informix-technology.blogspot.com My email works... but I don't check it frequently... ******************************************************************************* Forum Note: Use "Reply" to post a response in the discussion forum.
Hmmmm.... traditionally AIX devides the memory in "cache" and "program" memory. There were AIX versions (maybe late 5/ early 6) where the defaults tended to consider the machines were mainly file servers (!). So, heavy filesystem usage could "steal" program memory that could end up being paged out... But current versions AFAIK have reasonable defaults... It's a bit confusing issue... Involving an AIX specialist would be my advice.... Regards and good luck. On Fri, Oct 27, 2017 at 1:23 PM, Mueller, Daniel D. <DDMueller@west.com> wrote: > Fernando, > > Our "memory issue" in Not Informix related. It comes from the OS. I have a > suspicion that opening a very large file loads the entire file into memory > and > that is causing the issues. Unfortunately, we are not close to our > sysadmins > and we have not been able to prove/disprove that out. PMRs have been opened > and closed w/o much ado. > > We continue to try to get this one figured out but I have not seen Informix > grow past SHMTOTAL (not set to 0). Thank you so much for the followup > though. > I do appreciate all the help I can get. > > Dan > > -----Original Message----- > From: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org] On Behalf Of > Fernando > Nunes > Sent: Friday, October 27, 2017 5:33 AM > To: ids@iiug.org > Subject: Re: Can I bring informix up/down from another .... [40108] > > I didn't want to elaborate too much on this. I tried to answer the question > only... But "memory issues" are either a bug (memory leak) which must be > fixed, so a PMR must be opened, or bad engine / OS configuration (don't > take > this as criticism). > Either case needs investigation. > > Informix should not "eat" that much memory that would prevent a login on > the > machine. And it will only happen if SHMTOTAL is set to "0". I usually > recommend against this setting, precisely because a runaway engine can > "eat" > all the system memory and affect other instances on the same system or the > system itself. Naturally if a customer only has one instance on the machine > this is not as critical. > > Now... The big problem in setting it to something differently than "0" is > that > the parameter is not dynamic! I find it hard to understand why we can't > (yet) > change it dynamically at least to increase it. I could imagine issues on > decreasing it (if we try to lower it beyond the current instance usage. But > you already know me... I always think some code changes are easy... > probably > because I don't mess with the code myself, and because I don't have a tight > agenda of features and important customers pressuring with features I > consider > less important :) In other words, speaking is easy, doing it might me > slightly > harder :) > > Regarding RESIDENT set to -1... specially for AIX... again I think it's > kind > of a myth. I understand why we started to recommend this, and I know we had > issues with KAIO ( > http://www-01.ibm.com/support/docview.wss?uid=swg1IC76872) but again... > It's mainly a misconfiguration and some "dumb"(?) AIX defaults (pinnable > memory). Naturally, considering the seriousness of the possible effects, > -1 is > the safe and simple recommendation. > > Regards. > > On Fri, Oct 27, 2017 at 8:55 AM, Andreas Legner1 < > Andreas.Legner1@de.ibm.com > > wrote: > > > Also: RESIDENT -1 ? > > > > Could be contributing to 'memory issues', and shouldn't be required on > AIX. > > > > > > ************************************************************ > > ******************* > > Forum Note: Use "Reply" to post a response in the discussion forum. > > > > > > -- > Fernando Nunes > Portugal > > http://informix-technology.blogspot.com > My email works... but I don't check it frequently... > > > ************************************************************ > ******************* > Forum Note: Use "Reply" to post a response in the discussion forum. > > > ************************************************************ > ******************* > Forum Note: Use "Reply" to post a response in the discussion forum. > > -- Fernando Nunes Portugal http://informix-technology.blogspot.com My email works... but I don't check it frequently...
AIX file cache tuning is what your after. The defaults favor the file system side so they probably need to be tuned downwards. https://www.stix.id.au/wiki/Tuning_the_AIX_file_caches