topic Re: top question in Operating System - HP-UX

Re: top question

Franky_1 — Tue, 22 Jun 2004 10:10:48 GMT

Hi Scott,

i don't know about top causing real other problems. The only thing i know about is the fact, that top itself is consuming a lot of cpu time and therefore may cause a little trouble :)

HTH

Franky

Re: top question

Mark Grant — Tue, 22 Jun 2004 10:14:40 GMT

The only problem with top is that you have every user with shell access on the system thinking they can interpret "top"'s output properly and tell you that something is wrong with the system when it isn't.

Other than that and th elsight performance hit mentioned above, "top" is OK by me :)

Re: top question

Jeff_Traigle — Tue, 22 Jun 2004 10:16:21 GMT

Well, it's difficult to say without knowing what "other problems" this "someone" was talking about. I can't say that I've ever had problems related to top. I've even run Glance for extended periods without detrimental system performance. Of course, if your system is so resource constrained than running a performance monitoring tool is a problem, I'd say the problem isn't with the performance monitoring tool. :)

Re: top question

A. Clay Stephenson — Tue, 22 Jun 2004 10:16:50 GMT

Years ago there was a version of top that would dump core --- but's that's hardly a terrible system failure. As long as you are reasonably patched, top is stable and safe.

Probably the biggest downside of top is that people read much into it that is simply not there. For example, memory only refers to memory used by processes so that top's "real" memory is not at all related to physical memeory but many people make that false association.

The other downside is that like all measurement tools, the tool itself has overhead and thus affects the very thing you are trying to measure.

That being said, top is one of those tools that you should feel safe in using -- just be aware of its limitations.

Re: top question

Joseph Loo — Tue, 22 Jun 2004 10:20:12 GMT

hi,

i never had problem with running of top command. however, you may like to check using top if the top process is taking up too much CPU time.

also, check if there is any core dump after you "break out" of a existing top process, i.e. CTRL+C. you may need a patch if it do happens.

regards.

Re: top question

Steven E. Protter — Tue, 22 Jun 2004 10:56:21 GMT

I have used top on two or three versions of HP-UX and 5 or 6 versions of Linux with no issues.

There is no reason to have it running if nobody's looking at it, but it has never casued me a problem.

SEP

Re: top question

Dave Hutton — Tue, 22 Jun 2004 13:35:45 GMT

I've heard of issues actually with AIX on IBM servers and top. Could be the same myth though.

I do recall the last place I worked, removed top from the servers for some sort of reason. I don't think it was something as simple as not wanting end users who happened to have accounts on the server, trying to check out performance. I think there was something about it causing issues with the OS/hardware or something.

Not exactly an answer, but I had heard the same. Just not with HPUX.

Dave

Re: top question

Manish Srivastava — Tue, 22 Jun 2004 13:38:03 GMT

Hi,

As all the replies suggest there is no problem running top on the system. It is a harmless application running in user space it neither has root ownership nor is a setuid program. It surely does figure out in the top applications but that is hardly any "problem".

manish

Re: top question

Bharat Katkar — Tue, 22 Jun 2004 14:10:50 GMT

Hi,
TOP is a tool which helps you to monitor System performance and i believe the tool which itself encourage you to tune your system properly should not create any problem or add any considerable overheads on the system.
Inever had problem using TOP and it always helped me to monitor processor/processes alongwith CPU and memory.

Relax and keep using it.
Regards,