CPU USAGE DISPLAY (CPU Statistics)
On Jul 23, 2014, at 10:51, Schwab, Jos <Jos.Schwab at newellco.com> wrote:
Hello everyone, I am pretty new to the Linux world. Getting to the point quickly; xymon apparently uses the top display for the CPU display. When I see a CPU alert from xymon I’d like to see the current time interval’s CPU stats (The third line of top display - %us, %sy, %ni, etc) rather than the averages of those stats since the last reboot of the machine. This is an old ‘complaint’ in bugzilla which was closed in 2007 as ‘not a bug’. I couldn’t find any work-arounds or customizing tips out there to change the display in xymon. What changes can a person make to see the current time interval (any top display other than the first one) statistics for the cpu display in xymon? What about changes in the monitored OS? Any suggestions are appreciated! Thanks.
I think I know what you are asking for, but to be sure can you define what you mean by "current time interval" ?
Thanks!
Sorry for the delay mark. I took off a couple of days.
By interval I mean the time span that is used for the calculations in the cpu stats in the third line of TOP. The first display is calculated across the time since boot. The second 'interval' is the time calculated for those same cpu stats since the last iteration of the TOP display which is...well... it looks like 1 or 2 seconds. Thus that is what I mean by 'interval'. Interval is whatever is the measured period of time over which any given TOP display's cpu statistics are calculated. Xymon shows the first display of TOP which looks like the first screen shot below. Then from the same server virtually a few seconds later, I captured a second display of TOP. Notice the cpu statistics are very different even though the REAL condition of the server hadn't changed at all. I would like to change xymon to display that second iteration of the TOP command.
Let me know if you would like more clarification. Thanks! :)Jos Schwab Office - 815-233-8667 Mobile - 815-908-8587 SAP Technical Engineer 29 East Stephenson Street Freeport, Il. 61032
jos.schwab at newellco.com
-----Original Message----- From: Mark Felder [mailto:feld at feld.me] Sent: Wednesday, July 23, 2014 5:40 PM To: Schwab, Jos Cc: xymon at xymon.com Subject: Re: [Xymon] CPU USAGE DISPLAY (CPU Statistics)
On Jul 23, 2014, at 10:51, Schwab, Jos <Jos.Schwab at newellco.com<mailto:Jos.Schwab at newellco.com>> wrote:
Hello everyone, I am pretty new to the Linux world. Getting to the point quickly; xymon apparently uses the top display for the CPU display. When I see a CPU alert from xymon I'd like to see the current time interval's CPU stats (The third line of top display - %us, %sy, %ni, etc) rather than the averages of those stats since the last reboot of the machine. This is an old 'complaint' in bugzilla which was closed in 2007 as 'not a bug'. I couldn't find any work-arounds or customizing tips out there to change the display in xymon. What changes can a person make to see the current time interval (any top display other than the first one) statistics for the cpu display in xymon? What about changes in the monitored OS? Any suggestions are appreciated! Thanks.
I think I know what you are asking for, but to be sure can you define what you mean by "current time interval" ?
Thanks!
Mark, I failed to mention that in the man pages for TOP in CentOS 6.5, the -d command line option is called the interval which I had read somewhere is used to average statistics over. I hope that helps make it more clear and understandable.
Jos Schwab Office - 815-233-8667 Mobile - 815-908-8587 SAP Technical Engineer 29 East Stephenson Street Freeport, Il. 61032
jos.schwab at newellco.com
From: Schwab, Jos Sent: Tuesday, July 29, 2014 10:19 AM To: 'Mark Felder' Cc: xymon at xymon.com Subject: RE: [Xymon] CPU USAGE DISPLAY (CPU Statistics)
Sorry for the delay mark. I took off a couple of days.
By interval I mean the time span that is used for the calculations in the cpu stats in the third line of TOP. The first display is calculated across the time since boot. The second 'interval' is the time calculated for those same cpu stats since the last iteration of the TOP display which is...well... it looks like 1 or 2 seconds. Thus that is what I mean by 'interval'. Interval is whatever is the measured period of time over which any given TOP display's cpu statistics are calculated. Xymon shows the first display of TOP which looks like the first screen shot below. Then from the same server virtually a few seconds later, I captured a second display of TOP. Notice the cpu statistics are very different even though the REAL condition of the server hadn't changed at all. I would like to change xymon to display that second iteration of the TOP command.
Let me know if you would like more clarification. Thanks! :)
<< OLE Object: Picture (Device Independent Bitmap) >><< OLE Object: Picture (Device Independent Bitmap) >>
Jos Schwab Office - 815-233-8667 Mobile - 815-908-8587 SAP Technical Engineer 29 East Stephenson Street Freeport, Il. 61032
jos.schwab at newellco.com
-----Original Message----- From: Mark Felder [mailto:feld at feld.me] Sent: Wednesday, July 23, 2014 5:40 PM To: Schwab, Jos Cc: xymon at xymon.com Subject: Re: [Xymon] CPU USAGE DISPLAY (CPU Statistics)
On Jul 23, 2014, at 10:51, Schwab, Jos <Jos.Schwab at newellco.com<mailto:Jos.Schwab at newellco.com>> wrote:
Hello everyone, I am pretty new to the Linux world. Getting to the point quickly; xymon apparently uses the top display for the CPU display. When I see a CPU alert from xymon I'd like to see the current time interval's CPU stats (The third line of top display - %us, %sy, %ni, etc) rather than the averages of those stats since the last reboot of the machine. This is an old 'complaint' in bugzilla which was closed in 2007 as 'not a bug'. I couldn't find any work-arounds or customizing tips out there to change the display in xymon. What changes can a person make to see the current time interval (any top display other than the first one) statistics for the cpu display in xymon? What about changes in the monitored OS? Any suggestions are appreciated! Thanks.
I think I know what you are asking for, but to be sure can you define what you mean by "current time interval" ?
Thanks!
Mark, Lastly, I also see in the man pages for TOP in the bugs section (again on CentOS) the TOP author speaks to this very topic. He calls the intervals samples. Here is that except:
BUGS Send bug reports to: Albert D. Cahalan, <albert at users.sf.net>
The top command calculates Cpu(s) by looking at the change in CPU time values between samples. When you first run it, it has no previous sample to compare to, so these initial values are the percent- ages since boot. It means you need at least two loops or you have to ignore summary output from the first loop. This is problem for example for batch mode. There is a possible workaround if you define the CPULOOP=1 environment variable. The top command will be run one extra hidden loop for CPU data before standard output.
Jos Schwab Office - 815-233-8667 Mobile - 815-908-8587 SAP Technical Engineer 29 East Stephenson Street Freeport, Il. 61032
jos.schwab at newellco.com
From: Schwab, Jos Sent: Tuesday, July 29, 2014 10:56 AM To: 'Mark Felder' Cc: 'xymon at xymon.com' Subject: RE: [Xymon] CPU USAGE DISPLAY (CPU Statistics)
Mark, I failed to mention that in the man pages for TOP in CentOS 6.5, the -d command line option is called the interval which I had read somewhere is used to average statistics over. I hope that helps make it more clear and understandable.
Jos Schwab Office - 815-233-8667 Mobile - 815-908-8587 SAP Technical Engineer 29 East Stephenson Street Freeport, Il. 61032
jos.schwab at newellco.com<mailto:jos.schwab at newellco.com>
From: Schwab, Jos Sent: Tuesday, July 29, 2014 10:19 AM To: 'Mark Felder' Cc: xymon at xymon.com<mailto:xymon at xymon.com> Subject: RE: [Xymon] CPU USAGE DISPLAY (CPU Statistics)
Sorry for the delay mark. I took off a couple of days.
By interval I mean the time span that is used for the calculations in the cpu stats in the third line of TOP. The first display is calculated across the time since boot. The second 'interval' is the time calculated for those same cpu stats since the last iteration of the TOP display which is...well... it looks like 1 or 2 seconds. Thus that is what I mean by 'interval'. Interval is whatever is the measured period of time over which any given TOP display's cpu statistics are calculated. Xymon shows the first display of TOP which looks like the first screen shot below. Then from the same server virtually a few seconds later, I captured a second display of TOP. Notice the cpu statistics are very different even though the REAL condition of the server hadn't changed at all. I would like to change xymon to display that second iteration of the TOP command.
Let me know if you would like more clarification. Thanks! :)
<< OLE Object: Picture (Device Independent Bitmap) >><< OLE Object: Picture (Device Independent Bitmap) >>
Jos Schwab Office - 815-233-8667 Mobile - 815-908-8587 SAP Technical Engineer 29 East Stephenson Street Freeport, Il. 61032
jos.schwab at newellco.com<mailto:jos.schwab at newellco.com>
-----Original Message----- From: Mark Felder [mailto:feld at feld.me] Sent: Wednesday, July 23, 2014 5:40 PM To: Schwab, Jos Cc: xymon at xymon.com<mailto:xymon at xymon.com> Subject: Re: [Xymon] CPU USAGE DISPLAY (CPU Statistics)
On Jul 23, 2014, at 10:51, Schwab, Jos <Jos.Schwab at newellco.com<mailto:Jos.Schwab at newellco.com>> wrote:
Hello everyone, I am pretty new to the Linux world. Getting to the point quickly; xymon apparently uses the top display for the CPU display. When I see a CPU alert from xymon I'd like to see the current time interval's CPU stats (The third line of top display - %us, %sy, %ni, etc) rather than the averages of those stats since the last reboot of the machine. This is an old 'complaint' in bugzilla which was closed in 2007 as 'not a bug'. I couldn't find any work-arounds or customizing tips out there to change the display in xymon. What changes can a person make to see the current time interval (any top display other than the first one) statistics for the cpu display in xymon? What about changes in the monitored OS? Any suggestions are appreciated! Thanks.
I think I know what you are asking for, but to be sure can you define what you mean by "current time interval" ?
Thanks!
On Tue, July 29, 2014 9:05 am, Schwab, Jos wrote:
Mark, Lastly, I also see in the man pages for TOP in the bugs section (again on CentOS) the TOP author speaks to this very topic. He calls the intervals samples. Here is that except:
BUGS Send bug reports to: Albert D. Cahalan, <albert at users.sf.net>
The top command calculates Cpu(s) by looking at the change in CPUtime values between samples. When you first run it, it has no previous sample to compare to, so these initial values are the percent- ages since boot. It means you need at least two loops or you have to ignore summary output from the first loop. This is problem for example for batch mode. There is a possible workaround if you define the CPULOOP=1 environment variable. The top command will be run one extra hidden loop for CPU data before standard output.
From: Schwab, Jos Sent: Tuesday, July 29, 2014 10:56 AM To: 'Mark Felder' Cc: 'xymon at xymon.com' Subject: RE: [Xymon] CPU USAGE DISPLAY (CPU Statistics)
Mark, I failed to mention that in the man pages for TOP in CentOS 6.5, the -d command line option is called the interval which I had read somewhere is used to average statistics over. I hope that helps make it more clear and understandable.
Oof: https://bugzilla.redhat.com/show_bug.cgi?id=174619
Well, the system / idle / user etc percentages that end up getting graphed in xymon are actually coming from the vmstat command, being run on rotating 5 minute intervals, so the top output doesn't have an affect on those graphs (or alerting, really). That being said, that's fairly confusing, and it's a bit disappointing that procps doesn't call that out a little bit better in its batch mode.
As a quick workaround, you can add CPULOOP=1 to the end of /path/to/xymonclient.cfg and it should be in the environment for the $TOP call in xymonclient-linux.sh. ($TOP gets a -x test against it, so the command itself can't be modified to include env.)
That being said, this seems patch-worthy to at least give a more accurate
visual output. Wonder how non-Linux top's deal with this...
HTH, -jc
July 29 2014 6:19 PM, "J.C. Cleaver" wrote:
That being said, this seems patch-worthy to at least give a more accurate visual output. Wonder how non-Linux
top's deal with this...
FreeBSD: No CPU statistics shown in batch mode. In interactive mode the CPU statistics are blank until the second poll.
OpenBSD: Similar behavior to Linux. Their BUGS section in the man page says this:
BUGS As with ps(1), things can change while top is collecting information for an update. The picture it gives is only a close approximation to reality.
participants (3)
-
cleaver＠terabithia.org
-
feld＠feld.me
-
Jos.Schwab＠newellco.com