Re: [Nagios-users] NRPE vs NCSA
I agree, you should plan for expansion with nagios. No sense in limiting yourself with nrpe when you can just engineer for growth with nsca. I'm implementing the same configuration now, with nsca and I would like to point you to a document on the nagios website in the docs section. Someone wrote a very good howto to setup nsca. Regards, Richard On Wed, 2006-09-13 at 14:10 +0200, Thomas Sluyter wrote: > On 13 Sep, 2006, at 13:14, Hari Sekhon wrote: > > > While NCSA would reduce load slightly (probably not noticeably > > though I > > expect), NRPE would allow for a more centralised way of doing things, > > especially since I keep my entire nagios config under svn and like > > to be > > able to redeploy it centrally. > > > > Does anybody have any advice as to which I should go with? What > > have you > > used and what are your experiences of this? > > A few weeks ago I was stuck with the same question. Back then a > fellow by the pseudonym "Jakked Up" (he frequents many Nagios fora) > helped my out by discussing the matter over e-mail. > > One of the most important things to keep in mind is the amount of > checks you'll be performing and how things will be scheduled by Nagios. > > Say that you're running 1000 service checks through NRPE and that you > want them all run within 5 minutes. Let's assume that each service > check averages at 3 seconds before the results are in (best case > scenario). This would mean that Nagios would have a thousand three- > second connections open every five minutes. Parallelizing things > using the Nagios scheduler will help naturally... > > But now start thinking big... Around 7000 service checks? Would mean > 21.000 seconds worth of network connections crammed into five > minutes. That's not going to work nicely. > > And all of this is still excluding things like retries in the case of > a failure. Or assloads of retries in the case of massive failure. > > Now, if you take NSCA, the server will still be getting 7000 incoming > connections every five minutes, but: > 1) All incoming data will be dumped in the NSCA queue > 2) Nagios will "leisurely" pick through the NSCA queue to grab all > the status updates > > Or, as he originally put it: > > = > > To make a check on a remote system, via nrpe for example, nagios has > to schedule the check every 5 minutes, or whatever. > The check is made, which means a plugin runs a script that connects > to a daemon running remotely. The script then tells the daemon what > check to make. The check is made, the data passed on to the client > connection, and now nagios has the data for the check and processes > it. All of that is a lifetime, compared to: > > Periodically nagios reads it's external command file, whenever it has > time to do so, depending on your settings. At times, it finds > completed results of a service check. All nagios has to do is > process that result. So, the check is NOT even really made by the > central server. It's already sitting there for it. Of course, that > is only achieved via something like a passive check via nsca. > > = > > Me, I'll be making our new Nagios environment as passive as possible. > Most checks will be performed locally (scheduled through a small > wrapper script I wrote, run from cron), after which the results are > submitted through NSCA. For the remaining active checks I'll be using > net-SNMP. > > Cheers! > > > > Thomas > > - > Using Tomcat but need to do more? Need to support web services, security? > Get stuff done quickly with pre-integrated technology to make your job easier > Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo > http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 > ___ > Nagios-users mailing list > Nagios-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/nagios-users > ::: Please include Nagios version, plugin version (-v) and OS when reporting > any issue. > ::: Messages without supporting info will risk being sent to /dev/null > > !DSPAM:4507f53a60581166019105! > - Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 ___ Nagios-users mailing list Nagios-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nagios-users ::: Please include Nagios version, plugin version (-v) and OS when reporting any issue. ::: Messages without supporting info will risk being sent to /dev/null
Re: [Nagios-users] NRPE vs NCSA
On Wed, Sep 13, 2006 at 12:14:30PM +0100, Hari Sekhon wrote: > Does anybody have any advice as to which I should go with? What have you > used and what are your experiences of this? I'd take a security-based approach. I do not feel too comfortable with a server holding valueable or vital data is open to connection from the nagios host, which, as a host running a web interface, might be more easily compromised than the actual server. This is a minus for NRPE. With NSCA, the actual server would initiate the connection to the Nagios host which decreases security exposure. otoh, NSCA has a "gap" in data flow as nsca_send wants to see the output in a different format than the plugins put out. There are a bunch of shell scripts around that "translate" between the plugin and nsca_send, but these are like foreign objects in the nagios setup in my feelings. I think that there should be a "glue binary" written in C that calls the plugin and then hands over the results to nsca_send. Greetings Marc -- - Marc Haber | "I don't trust Computers. They | Mailadresse im Header Mannheim, Germany | lose things."Winona Ryder | Fon: *49 621 72739834 Nordisch by Nature | How to make an American Quilt | Fax: *49 621 72739835 - Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 ___ Nagios-users mailing list Nagios-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nagios-users ::: Please include Nagios version, plugin version (-v) and OS when reporting any issue. ::: Messages without supporting info will risk being sent to /dev/null
Re: [Nagios-users] NRPE vs NCSA
On 13 Sep, 2006, at 13:14, Hari Sekhon wrote: > While NCSA would reduce load slightly (probably not noticeably > though I > expect), NRPE would allow for a more centralised way of doing things, > especially since I keep my entire nagios config under svn and like > to be > able to redeploy it centrally. > > Does anybody have any advice as to which I should go with? What > have you > used and what are your experiences of this? A few weeks ago I was stuck with the same question. Back then a fellow by the pseudonym "Jakked Up" (he frequents many Nagios fora) helped my out by discussing the matter over e-mail. One of the most important things to keep in mind is the amount of checks you'll be performing and how things will be scheduled by Nagios. Say that you're running 1000 service checks through NRPE and that you want them all run within 5 minutes. Let's assume that each service check averages at 3 seconds before the results are in (best case scenario). This would mean that Nagios would have a thousand three- second connections open every five minutes. Parallelizing things using the Nagios scheduler will help naturally... But now start thinking big... Around 7000 service checks? Would mean 21.000 seconds worth of network connections crammed into five minutes. That's not going to work nicely. And all of this is still excluding things like retries in the case of a failure. Or assloads of retries in the case of massive failure. Now, if you take NSCA, the server will still be getting 7000 incoming connections every five minutes, but: 1) All incoming data will be dumped in the NSCA queue 2) Nagios will "leisurely" pick through the NSCA queue to grab all the status updates Or, as he originally put it: = To make a check on a remote system, via nrpe for example, nagios has to schedule the check every 5 minutes, or whatever. The check is made, which means a plugin runs a script that connects to a daemon running remotely. The script then tells the daemon what check to make. The check is made, the data passed on to the client connection, and now nagios has the data for the check and processes it. All of that is a lifetime, compared to: Periodically nagios reads it's external command file, whenever it has time to do so, depending on your settings. At times, it finds completed results of a service check. All nagios has to do is process that result. So, the check is NOT even really made by the central server. It's already sitting there for it. Of course, that is only achieved via something like a passive check via nsca. = Me, I'll be making our new Nagios environment as passive as possible. Most checks will be performed locally (scheduled through a small wrapper script I wrote, run from cron), after which the results are submitted through NSCA. For the remaining active checks I'll be using net-SNMP. Cheers! Thomas - Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 ___ Nagios-users mailing list Nagios-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nagios-users ::: Please include Nagios version, plugin version (-v) and OS when reporting any issue. ::: Messages without supporting info will risk being sent to /dev/null
Re: [Nagios-users] NRPE vs NCSA
Hi, On Wed, 2006-09-13 at 12:28 +0100, Hari Sekhon wrote: > Marco Ramos wrote: > > Hi, > > > > On Wed, 2006-09-13 at 12:14 +0100, Hari Sekhon wrote: > > > > > I want to extend my nagios configuration to cover things like disk space > > > on servers etc so I need to evaluate which is better for this purpose: > > > NRPE or NCSA. > > > > > > > IMHO, you should also consider SNMP. > > > > Best regards, > > Marco Ramos > > > > > > > I believe that looking at the (very) brief doc that comes with Nagios > > > that NRPE is a server side executor which tells the remote host "go run > > > this plug-in and pass the result back to me", whereas NCSA executes > > > itself on the host side and then sends the result to a listening NCSAd > > > on the monitoring server running Nagios. > > > > > > So it comes down to active server initiated test or passive client > > > initiated test. > > > > > > While NCSA would reduce load slightly (probably not noticeably though I > > > expect), NRPE would allow for a more centralised way of doing things, > > > especially since I keep my entire nagios config under svn and like to be > > > able to redeploy it centrally. > > > > > > Does anybody have any advice as to which I should go with? What have you > > > used and what are your experiences of this? > > > > > > -h > > > > > > > > > seeing as I've never used snmp (it's on my todo list) I'd need a bit > more of a guideline than that... How would you get check results, what > would you run on the client, what would you run on the server? > As I see it, SNMP has a major advantage: it's a industry standard. For instance, if you also monitor routers or other network equipment, you can't install nrpe or nsca on it. There are also other advantages. There are many servers/applications (jabber, squid, etc, etc) that have SNMP built-in support, so that you can use that you can monitor a lot of things with SNMP. Other advantage is the fact that you can use SNMP not only with Nagios, but also with stats application (like Cacti or other rrdtool based application ) which greatly reduces the ammount of software you'll have to install on your servers. It's really simple to start using SNMP. Take a look at Net-SNMP (http://net-snmp.sourceforge.net). After understanding how it works, you just have to identify the OIDs of the things you want to monitor and make some simple scripts to monitor them. For instance, I use perl scripts with the Net::SNMP module on my Nagios server to check disk space, load average and all that kind of stuff on my monitored servers. HTH, Marco Ramos > -h > > -- > Hari Sekhon > - > Using Tomcat but need to do more? Need to support web services, security? > Get stuff done quickly with pre-integrated technology to make your job easier > Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo > http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 > ___ Nagios-users mailing list > Nagios-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/nagios-users ::: Please include > Nagios version, plugin version (-v) and OS when reporting any issue. ::: > Messages without supporting info will risk being sent to /dev/null - Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 ___ Nagios-users mailing list Nagios-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nagios-users ::: Please include Nagios version, plugin version (-v) and OS when reporting any issue. ::: Messages without supporting info will risk being sent to /dev/null
Re: [Nagios-users] NRPE vs NCSA
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Hari Sekhon wrote: > > Does anybody have any advice as to which I should go with? What have you > used and what are your experiences of this? For everything I can't check across SNMP, I use NRPE. I just started using it less than a year ago for a few things. I like it because of my distribution though, the repo I use RPMs from has NRPE and Nagios all ready to go. This makes it perfect for my use, so your application of it may vary. Anyways, back to NRPE. I haven't noticed any overhead with processing checks even on older machines. My advice would be load both NCSA and NRPE up on a machine or two and experiment first. That way you can see for yourself which one you prefer to use. Let me know if you run Red Hat or a CentOS flavor and you decide to go with NRPE. I can assist with setting it up. ;) Max -BEGIN PGP SIGNATURE- Version: GnuPG v1.2.6 (GNU/Linux) Comment: Using GnuPG with CentOS - http://enigmail.mozdev.org iD8DBQFFB+tUHoeeepPau2ERAvoFAJ4qS4Ua77zJ/4y3ogRazeE5pISQaACfdeLq Qo2VTjF2TiS85jc/lpVeRX4= =Cbm6 -END PGP SIGNATURE- - Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 ___ Nagios-users mailing list Nagios-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nagios-users ::: Please include Nagios version, plugin version (-v) and OS when reporting any issue. ::: Messages without supporting info will risk being sent to /dev/null
Re: [Nagios-users] NRPE vs NCSA
Marco Ramos wrote: Hi, On Wed, 2006-09-13 at 12:14 +0100, Hari Sekhon wrote: I want to extend my nagios configuration to cover things like disk space on servers etc so I need to evaluate which is better for this purpose: NRPE or NCSA. IMHO, you should also consider SNMP. Best regards, Marco Ramos I believe that looking at the (very) brief doc that comes with Nagios that NRPE is a server side executor which tells the remote host "go run this plug-in and pass the result back to me", whereas NCSA executes itself on the host side and then sends the result to a listening NCSAd on the monitoring server running Nagios. So it comes down to active server initiated test or passive client initiated test. While NCSA would reduce load slightly (probably not noticeably though I expect), NRPE would allow for a more centralised way of doing things, especially since I keep my entire nagios config under svn and like to be able to redeploy it centrally. Does anybody have any advice as to which I should go with? What have you used and what are your experiences of this? -h seeing as I've never used snmp (it's on my todo list) I'd need a bit more of a guideline than that... How would you get check results, what would you run on the client, what would you run on the server? -h -- Hari Sekhon - Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642___ Nagios-users mailing list Nagios-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nagios-users ::: Please include Nagios version, plugin version (-v) and OS when reporting any issue. ::: Messages without supporting info will risk being sent to /dev/null
Re: [Nagios-users] NRPE vs NCSA
Hi, On Wed, 2006-09-13 at 12:14 +0100, Hari Sekhon wrote: > I want to extend my nagios configuration to cover things like disk space > on servers etc so I need to evaluate which is better for this purpose: > NRPE or NCSA. IMHO, you should also consider SNMP. Best regards, Marco Ramos > I believe that looking at the (very) brief doc that comes with Nagios > that NRPE is a server side executor which tells the remote host "go run > this plug-in and pass the result back to me", whereas NCSA executes > itself on the host side and then sends the result to a listening NCSAd > on the monitoring server running Nagios. > > So it comes down to active server initiated test or passive client > initiated test. > > While NCSA would reduce load slightly (probably not noticeably though I > expect), NRPE would allow for a more centralised way of doing things, > especially since I keep my entire nagios config under svn and like to be > able to redeploy it centrally. > > Does anybody have any advice as to which I should go with? What have you > used and what are your experiences of this? > > -h > - Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 ___ Nagios-users mailing list Nagios-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nagios-users ::: Please include Nagios version, plugin version (-v) and OS when reporting any issue. ::: Messages without supporting info will risk being sent to /dev/null
[Nagios-users] NRPE vs NCSA
I want to extend my nagios configuration to cover things like disk space on servers etc so I need to evaluate which is better for this purpose: NRPE or NCSA. I believe that looking at the (very) brief doc that comes with Nagios that NRPE is a server side executor which tells the remote host "go run this plug-in and pass the result back to me", whereas NCSA executes itself on the host side and then sends the result to a listening NCSAd on the monitoring server running Nagios. So it comes down to active server initiated test or passive client initiated test. While NCSA would reduce load slightly (probably not noticeably though I expect), NRPE would allow for a more centralised way of doing things, especially since I keep my entire nagios config under svn and like to be able to redeploy it centrally. Does anybody have any advice as to which I should go with? What have you used and what are your experiences of this? -h -- Hari Sekhon - Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 ___ Nagios-users mailing list Nagios-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nagios-users ::: Please include Nagios version, plugin version (-v) and OS when reporting any issue. ::: Messages without supporting info will risk being sent to /dev/null
