Re: [Nagios-users] Dependent service checks don't fail when depended-on service check fails
Jarrod Moore wrote: > On Mon, Mar 30, 2009 at 10:13 PM, Andreas Ericsson wrote: >> Jarrod Moore wrote: >>> On Thu, Mar 26, 2009 at 7:57 PM, Andreas Ericsson wrote: Jarrod Moore wrote: > Hello everyone, > > I have a couple of related questions regarding service dependencies in > Nagios and their limitations. I have two service checks (let's call > them A and B) and service A depends on service B to function > correctly. I want to set Nagios up so that if service B crashes then > both services A and B are put into the critical state in Nagios. I've > tried using service dependencies in Nagios to represent this behaviour > but have yet to be successful. I can only get it to suppress > notifications of service A if both services go down. > This is expected behaviour. If A is truly dependant on B, then A will turn into a non-ok state of its own volition rather than as a result of any dependency magic. Dependencies are designed as a means of suppressing notifications. Otherwise, you would *always* get a notification for B first, and a minute or so later from A (actually, without the dependency you could get from A first). > Is there a way to do what I'm trying to do here? I'd have thought it > would be logical that if a service depends on another service and the > service depended on dies then all services depending on it would fail > their checks as well, but there;s probably some scenario where it > doesn't work so well. I've had a look through the mailing list > archives and found someone had asked a similar question to the > nagios-devel list about 2.5 years ago and didn't end up getting an > answer, so I thought I might ask whether solutions to this type of > problem had been developed since then. > They haven't. You're using dependencies the wrong way, really. If A is truly dependent on B and doesn't go into a non-ok state after B has crashed, then your check isn't doing what it's supposed to do, or you've misunderstood the relationship somehow. If you were to explain what the two services actually are, it would be easier to point you to a solution that works. -- Andreas Ericsson andreas.erics...@op5.se OP5 AB www.op5.se Tel: +46 8-230225 Fax: +46 8-230231 Considering the successes of the wars on alcohol, poverty, drugs and terror, I think we should give some serious thought to declaring war on peace. >>> Well basically I have a map (similar to Google Maps) embedded in a >>> website, which hits a URL to retrieve maps. So I have one check using >>> check_http to check that the website itself is up and another check on >>> that URL to make sure that the map service is available. Now if the >>> map service goes down, the website is still up but the maps won't >>> appear, which means the website's functionality is significantly >>> affected. However, it is still up and viewable so doing a check on the >>> website URL still passes. >>> >> It sounds to me like you'd want to make the map-check dependent on >> the webserver-check. That would suppress notifications from the >> map-check when it's the webserver that's bombing out. Do you really >> need two notifications when the map-service goes offline? > > Sorry, I didn't explain that very well. I have a website check that I > want to have depend on the result of a map service check. The thing is > that I would like two notifications to be sent to my email - one for > the service check that is failing and one for each site that is > affected by the crashed service. That way I would know what is > affected and what needs fixing. Now I should mention at this point (if > it wasn't already blindingly obvious) that I'm by no means a Nagios > master. However, my idea was to have a chain of service dependencies > and then not send notifications for service dependencies in between > that I don't want emails about. There's probably a better way of doing > what I want and in that case, I'm all ... eyes. > >>> Now of course I could just write a script or something to check both >>> URLs and set that as the check command. There is a problem for me with >>> this approach, however, because I have some other instances where a >>> web service depends on other web services. >> Define "depend". As I understand the definition, coal-based lifeforms >> on our fine planet depend on water and sunlight; Life cannot function >> properly without them. >> It sounds like you want to make sunlight depend on coal-based lifeforms, >> because without the life, the sun is rather pointless. >> >> Instead of trying to coerce dependencies to work backwards, I'd sit >> down and think what you want your Nagios installation to do for you, >> and why you would want two services to go critical when one of them >> does. Isn't one noti
Re: [Nagios-users] Dependent service checks don't fail when depended-on service check fails
Jarrod Moore wrote: > On Fri, Mar 27, 2009 at 5:43 PM, Matthias Flacke > wrote: >> Jarrod Moore wrote: >>> On Thu, Mar 26, 2009 at 7:57 PM, Andreas Ericsson wrote: Jarrod Moore wrote: > Hello everyone, > > I have a couple of related questions regarding service dependencies in > Nagios and their limitations. I have two service checks (let's call > them A and B) and service A depends on service B to function > correctly. I want to set Nagios up so that if service B crashes then > both services A and B are put into the critical state in Nagios. I've > tried using service dependencies in Nagios to represent this behaviour > but have yet to be successful. I can only get it to suppress > notifications of service A if both services go down. > This is expected behaviour. If A is truly dependant on B, then A will turn into a non-ok state of its own volition rather than as a result of any dependency magic. Dependencies are designed as a means of suppressing notifications. Otherwise, you would *always* get a notification for B first, and a minute or so later from A (actually, without the dependency you could get from A first). > Is there a way to do what I'm trying to do here? I'd have thought it > would be logical that if a service depends on another service and the > service depended on dies then all services depending on it would fail > their checks as well, but there;s probably some scenario where it > doesn't work so well. I've had a look through the mailing list > archives and found someone had asked a similar question to the > nagios-devel list about 2.5 years ago and didn't end up getting an > answer, so I thought I might ask whether solutions to this type of > problem had been developed since then. > They haven't. You're using dependencies the wrong way, really. If A is truly dependent on B and doesn't go into a non-ok state after B has crashed, then your check isn't doing what it's supposed to do, or you've misunderstood the relationship somehow. If you were to explain what the two services actually are, it would be easier to point you to a solution that works. -- Andreas Ericsson andreas.erics...@op5.se OP5 AB www.op5.se Tel: +46 8-230225 Fax: +46 8-230231 Considering the successes of the wars on alcohol, poverty, drugs and terror, I think we should give some serious thought to declaring war on peace. >>> Well basically I have a map (similar to Google Maps) embedded in a >>> website, which hits a URL to retrieve maps. So I have one check using >>> check_http to check that the website itself is up and another check on >>> that URL to make sure that the map service is available. Now if the >>> map service goes down, the website is still up but the maps won't >>> appear, which means the website's functionality is significantly >>> affected. However, it is still up and viewable so doing a check on the >>> website URL still passes. >>> >>> Now of course I could just write a script or something to check both >>> URLs and set that as the check command. There is a problem for me with >>> this approach, however, because I have some other instances where a >>> web service depends on other web services. When I want to use these >>> services in websites, I'd then have to write a check for each script, >>> each containing every service in the chain that is needed to display >>> the website correctly. This way of doing things just seems a bit >>> repetitive to me, especially when I have a check for these web >>> services already. >> You can give check_multi a try (http://my-plugin.de/check_multi). >> >> It allows to combine multiple checks on plugin level and has a >> builtin state logic to evaluate the results of these checks. >> You can reuse the command files by implementing macros. >> >> If I understood your setup correctly the whole result should return >> CRITICAL if either the main website or the map are not accessible. >> This is the standard behaviour of check_multi and could be >> implemented like this: >> >> # foo.cmd >> # call: check_multi -f -s URLWEB= -s >> URLMAP= >> command [ website ] = check_http ... -u $URLWEB$ ... >> command [ map ] = check_http ... -u $URLMAP$ ... >> >> It should work already with these two statements like you expect it >> with simple check_http, only combined. If one of the child checks >> fails, the whole construct returns WARNING or CRITICAL. >> >> If you need the RC determination more sophisticated, you can define >> it in perl syntax like this: >> state [ WARNING ] = website != OK || $website$=~/some evil output/ >> state [ CRITICAL] = website >= WARNING && map != OK >> >> Cheers, >> -Matthias >> > > Hi Matthias, > > Thanks for the link. I've been checking (no pun intended) out > check_multi over th
Re: [Nagios-users] Dependent service checks don't fail when depended-on service check fails
On Mon, Mar 30, 2009 at 10:13 PM, Andreas Ericsson wrote: > Jarrod Moore wrote: >> >> On Thu, Mar 26, 2009 at 7:57 PM, Andreas Ericsson wrote: >>> >>> Jarrod Moore wrote: Hello everyone, I have a couple of related questions regarding service dependencies in Nagios and their limitations. I have two service checks (let's call them A and B) and service A depends on service B to function correctly. I want to set Nagios up so that if service B crashes then both services A and B are put into the critical state in Nagios. I've tried using service dependencies in Nagios to represent this behaviour but have yet to be successful. I can only get it to suppress notifications of service A if both services go down. >>> This is expected behaviour. If A is truly dependant on B, then A will >>> turn into a non-ok state of its own volition rather than as a result >>> of any dependency magic. Dependencies are designed as a means of >>> suppressing notifications. Otherwise, you would *always* get a >>> notification for B first, and a minute or so later from A (actually, >>> without the dependency you could get from A first). >>> Is there a way to do what I'm trying to do here? I'd have thought it would be logical that if a service depends on another service and the service depended on dies then all services depending on it would fail their checks as well, but there;s probably some scenario where it doesn't work so well. I've had a look through the mailing list archives and found someone had asked a similar question to the nagios-devel list about 2.5 years ago and didn't end up getting an answer, so I thought I might ask whether solutions to this type of problem had been developed since then. >>> They haven't. You're using dependencies the wrong way, really. If >>> A is truly dependent on B and doesn't go into a non-ok state after >>> B has crashed, then your check isn't doing what it's supposed to do, >>> or you've misunderstood the relationship somehow. >>> >>> If you were to explain what the two services actually are, it would >>> be easier to point you to a solution that works. >>> >>> -- >>> Andreas Ericsson andreas.erics...@op5.se >>> OP5 AB www.op5.se >>> Tel: +46 8-230225 Fax: +46 8-230231 >>> >>> Considering the successes of the wars on alcohol, poverty, drugs and >>> terror, I think we should give some serious thought to declaring war >>> on peace. >>> >> >> Well basically I have a map (similar to Google Maps) embedded in a >> website, which hits a URL to retrieve maps. So I have one check using >> check_http to check that the website itself is up and another check on >> that URL to make sure that the map service is available. Now if the >> map service goes down, the website is still up but the maps won't >> appear, which means the website's functionality is significantly >> affected. However, it is still up and viewable so doing a check on the >> website URL still passes. >> > > It sounds to me like you'd want to make the map-check dependent on > the webserver-check. That would suppress notifications from the > map-check when it's the webserver that's bombing out. Do you really > need two notifications when the map-service goes offline? Sorry, I didn't explain that very well. I have a website check that I want to have depend on the result of a map service check. The thing is that I would like two notifications to be sent to my email - one for the service check that is failing and one for each site that is affected by the crashed service. That way I would know what is affected and what needs fixing. Now I should mention at this point (if it wasn't already blindingly obvious) that I'm by no means a Nagios master. However, my idea was to have a chain of service dependencies and then not send notifications for service dependencies in between that I don't want emails about. There's probably a better way of doing what I want and in that case, I'm all ... eyes. >> Now of course I could just write a script or something to check both >> URLs and set that as the check command. There is a problem for me with >> this approach, however, because I have some other instances where a >> web service depends on other web services. > > Define "depend". As I understand the definition, coal-based lifeforms > on our fine planet depend on water and sunlight; Life cannot function > properly without them. > It sounds like you want to make sunlight depend on coal-based lifeforms, > because without the life, the sun is rather pointless. > > Instead of trying to coerce dependencies to work backwards, I'd sit > down and think what you want your Nagios installation to do for you, > and why you would want two services to go critical when one of them > does. Isn't one notification and one red blob in the UI enough? If > it isn't, what do you hope to gain from having two noti
Re: [Nagios-users] Dependent service checks don't fail when depended-on service check fails
On Fri, Mar 27, 2009 at 5:43 PM, Matthias Flacke wrote: > > Jarrod Moore wrote: >> On Thu, Mar 26, 2009 at 7:57 PM, Andreas Ericsson wrote: >>> Jarrod Moore wrote: Hello everyone, I have a couple of related questions regarding service dependencies in Nagios and their limitations. I have two service checks (let's call them A and B) and service A depends on service B to function correctly. I want to set Nagios up so that if service B crashes then both services A and B are put into the critical state in Nagios. I've tried using service dependencies in Nagios to represent this behaviour but have yet to be successful. I can only get it to suppress notifications of service A if both services go down. >>> This is expected behaviour. If A is truly dependant on B, then A will >>> turn into a non-ok state of its own volition rather than as a result >>> of any dependency magic. Dependencies are designed as a means of >>> suppressing notifications. Otherwise, you would *always* get a >>> notification for B first, and a minute or so later from A (actually, >>> without the dependency you could get from A first). >>> Is there a way to do what I'm trying to do here? I'd have thought it would be logical that if a service depends on another service and the service depended on dies then all services depending on it would fail their checks as well, but there;s probably some scenario where it doesn't work so well. I've had a look through the mailing list archives and found someone had asked a similar question to the nagios-devel list about 2.5 years ago and didn't end up getting an answer, so I thought I might ask whether solutions to this type of problem had been developed since then. >>> They haven't. You're using dependencies the wrong way, really. If >>> A is truly dependent on B and doesn't go into a non-ok state after >>> B has crashed, then your check isn't doing what it's supposed to do, >>> or you've misunderstood the relationship somehow. >>> >>> If you were to explain what the two services actually are, it would >>> be easier to point you to a solution that works. >>> >>> -- >>> Andreas Ericsson andreas.erics...@op5.se >>> OP5 AB www.op5.se >>> Tel: +46 8-230225 Fax: +46 8-230231 >>> >>> Considering the successes of the wars on alcohol, poverty, drugs and >>> terror, I think we should give some serious thought to declaring war >>> on peace. >>> >> >> Well basically I have a map (similar to Google Maps) embedded in a >> website, which hits a URL to retrieve maps. So I have one check using >> check_http to check that the website itself is up and another check on >> that URL to make sure that the map service is available. Now if the >> map service goes down, the website is still up but the maps won't >> appear, which means the website's functionality is significantly >> affected. However, it is still up and viewable so doing a check on the >> website URL still passes. >> >> Now of course I could just write a script or something to check both >> URLs and set that as the check command. There is a problem for me with >> this approach, however, because I have some other instances where a >> web service depends on other web services. When I want to use these >> services in websites, I'd then have to write a check for each script, >> each containing every service in the chain that is needed to display >> the website correctly. This way of doing things just seems a bit >> repetitive to me, especially when I have a check for these web >> services already. > > You can give check_multi a try (http://my-plugin.de/check_multi). > > It allows to combine multiple checks on plugin level and has a > builtin state logic to evaluate the results of these checks. > You can reuse the command files by implementing macros. > > If I understood your setup correctly the whole result should return > CRITICAL if either the main website or the map are not accessible. > This is the standard behaviour of check_multi and could be > implemented like this: > > # foo.cmd > # call: check_multi -f -s URLWEB= -s > URLMAP= > command [ website ] = check_http ... -u $URLWEB$ ... > command [ map ] = check_http ... -u $URLMAP$ ... > > It should work already with these two statements like you expect it > with simple check_http, only combined. If one of the child checks > fails, the whole construct returns WARNING or CRITICAL. > > If you need the RC determination more sophisticated, you can define > it in perl syntax like this: > state [ WARNING ] = website != OK || $website$=~/some evil output/ > state [ CRITICAL] = website >= WARNING && map != OK > > Cheers, > -Matthias > Hi Matthias, Thanks for the link. I've been checking (no pun intended) out check_multi over the last day or two and I like it. My main concern with this, though, is that if I had 10 websites that were dependent on the m
Re: [Nagios-users] Dependent service checks don't fail when depended-on service check fails
Jarrod Moore wrote: > On Thu, Mar 26, 2009 at 7:57 PM, Andreas Ericsson wrote: >> Jarrod Moore wrote: >>> Hello everyone, >>> >>> I have a couple of related questions regarding service dependencies in >>> Nagios and their limitations. I have two service checks (let's call >>> them A and B) and service A depends on service B to function >>> correctly. I want to set Nagios up so that if service B crashes then >>> both services A and B are put into the critical state in Nagios. I've >>> tried using service dependencies in Nagios to represent this behaviour >>> but have yet to be successful. I can only get it to suppress >>> notifications of service A if both services go down. >>> >> This is expected behaviour. If A is truly dependant on B, then A will >> turn into a non-ok state of its own volition rather than as a result >> of any dependency magic. Dependencies are designed as a means of >> suppressing notifications. Otherwise, you would *always* get a >> notification for B first, and a minute or so later from A (actually, >> without the dependency you could get from A first). >> >>> Is there a way to do what I'm trying to do here? I'd have thought it >>> would be logical that if a service depends on another service and the >>> service depended on dies then all services depending on it would fail >>> their checks as well, but there;s probably some scenario where it >>> doesn't work so well. I've had a look through the mailing list >>> archives and found someone had asked a similar question to the >>> nagios-devel list about 2.5 years ago and didn't end up getting an >>> answer, so I thought I might ask whether solutions to this type of >>> problem had been developed since then. >>> >> They haven't. You're using dependencies the wrong way, really. If >> A is truly dependent on B and doesn't go into a non-ok state after >> B has crashed, then your check isn't doing what it's supposed to do, >> or you've misunderstood the relationship somehow. >> >> If you were to explain what the two services actually are, it would >> be easier to point you to a solution that works. >> >> -- >> Andreas Ericsson andreas.erics...@op5.se >> OP5 AB www.op5.se >> Tel: +46 8-230225 Fax: +46 8-230231 >> >> Considering the successes of the wars on alcohol, poverty, drugs and >> terror, I think we should give some serious thought to declaring war >> on peace. >> > > Well basically I have a map (similar to Google Maps) embedded in a > website, which hits a URL to retrieve maps. So I have one check using > check_http to check that the website itself is up and another check on > that URL to make sure that the map service is available. Now if the > map service goes down, the website is still up but the maps won't > appear, which means the website's functionality is significantly > affected. However, it is still up and viewable so doing a check on the > website URL still passes. > It sounds to me like you'd want to make the map-check dependent on the webserver-check. That would suppress notifications from the map-check when it's the webserver that's bombing out. Do you really need two notifications when the map-service goes offline? > Now of course I could just write a script or something to check both > URLs and set that as the check command. There is a problem for me with > this approach, however, because I have some other instances where a > web service depends on other web services. Define "depend". As I understand the definition, coal-based lifeforms on our fine planet depend on water and sunlight; Life cannot function properly without them. It sounds like you want to make sunlight depend on coal-based lifeforms, because without the life, the sun is rather pointless. Instead of trying to coerce dependencies to work backwards, I'd sit down and think what you want your Nagios installation to do for you, and why you would want two services to go critical when one of them does. Isn't one notification and one red blob in the UI enough? If it isn't, what do you hope to gain from having two notifications and two red blobs? > When I want to use these > services in websites, I'd then have to write a check for each script, > each containing every service in the chain that is needed to display > the website correctly. This way of doing things just seems a bit > repetitive to me, especially when I have a check for these web > services already. I'm sorry, but I still fail to see the point. Perhaps you'd be better off defining each website as a servicegroup with all of the services that make up the entire visitor-experience parts of a particular servicegroup. That would make it possible for you to get some sort of visualization of what (Nagios-)services affect which customer-services, while at the same time keeping configuration work to a minimum. -- Andreas Ericsson andreas.erics...@op5.se OP5 AB www.op5.se Tel: +46 8-230225
Re: [Nagios-users] Dependent service checks don't fail when depended-on service check fails
Jarrod Moore wrote: > On Thu, Mar 26, 2009 at 7:57 PM, Andreas Ericsson wrote: >> Jarrod Moore wrote: >>> Hello everyone, >>> >>> I have a couple of related questions regarding service dependencies in >>> Nagios and their limitations. I have two service checks (let's call >>> them A and B) and service A depends on service B to function >>> correctly. I want to set Nagios up so that if service B crashes then >>> both services A and B are put into the critical state in Nagios. I've >>> tried using service dependencies in Nagios to represent this behaviour >>> but have yet to be successful. I can only get it to suppress >>> notifications of service A if both services go down. >>> >> This is expected behaviour. If A is truly dependant on B, then A will >> turn into a non-ok state of its own volition rather than as a result >> of any dependency magic. Dependencies are designed as a means of >> suppressing notifications. Otherwise, you would *always* get a >> notification for B first, and a minute or so later from A (actually, >> without the dependency you could get from A first). >> >>> Is there a way to do what I'm trying to do here? I'd have thought it >>> would be logical that if a service depends on another service and the >>> service depended on dies then all services depending on it would fail >>> their checks as well, but there;s probably some scenario where it >>> doesn't work so well. I've had a look through the mailing list >>> archives and found someone had asked a similar question to the >>> nagios-devel list about 2.5 years ago and didn't end up getting an >>> answer, so I thought I might ask whether solutions to this type of >>> problem had been developed since then. >>> >> They haven't. You're using dependencies the wrong way, really. If >> A is truly dependent on B and doesn't go into a non-ok state after >> B has crashed, then your check isn't doing what it's supposed to do, >> or you've misunderstood the relationship somehow. >> >> If you were to explain what the two services actually are, it would >> be easier to point you to a solution that works. >> >> -- >> Andreas Ericsson andreas.erics...@op5.se >> OP5 AB www.op5.se >> Tel: +46 8-230225 Fax: +46 8-230231 >> >> Considering the successes of the wars on alcohol, poverty, drugs and >> terror, I think we should give some serious thought to declaring war >> on peace. >> > > Well basically I have a map (similar to Google Maps) embedded in a > website, which hits a URL to retrieve maps. So I have one check using > check_http to check that the website itself is up and another check on > that URL to make sure that the map service is available. Now if the > map service goes down, the website is still up but the maps won't > appear, which means the website's functionality is significantly > affected. However, it is still up and viewable so doing a check on the > website URL still passes. > > Now of course I could just write a script or something to check both > URLs and set that as the check command. There is a problem for me with > this approach, however, because I have some other instances where a > web service depends on other web services. When I want to use these > services in websites, I'd then have to write a check for each script, > each containing every service in the chain that is needed to display > the website correctly. This way of doing things just seems a bit > repetitive to me, especially when I have a check for these web > services already. You can give check_multi a try (http://my-plugin.de/check_multi). It allows to combine multiple checks on plugin level and has a builtin state logic to evaluate the results of these checks. You can reuse the command files by implementing macros. If I understood your setup correctly the whole result should return CRITICAL if either the main website or the map are not accessible. This is the standard behaviour of check_multi and could be implemented like this: # foo.cmd # call: check_multi -f -s URLWEB= -s URLMAP= command [ website ] = check_http ... -u $URLWEB$ ... command [ map ] = check_http ... -u $URLMAP$ ... It should work already with these two statements like you expect it with simple check_http, only combined. If one of the child checks fails, the whole construct returns WARNING or CRITICAL. If you need the RC determination more sophisticated, you can define it in perl syntax like this: state [ WARNING ] = website != OK || $website$=~/some evil output/ state [ CRITICAL] = website >= WARNING && map != OK Cheers, -Matthias -- ___ 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
Re: [Nagios-users] Dependent service checks don't fail when depended-on service check fails
On Thu, Mar 26, 2009 at 7:57 PM, Andreas Ericsson wrote: > Jarrod Moore wrote: >> >> Hello everyone, >> >> I have a couple of related questions regarding service dependencies in >> Nagios and their limitations. I have two service checks (let's call >> them A and B) and service A depends on service B to function >> correctly. I want to set Nagios up so that if service B crashes then >> both services A and B are put into the critical state in Nagios. I've >> tried using service dependencies in Nagios to represent this behaviour >> but have yet to be successful. I can only get it to suppress >> notifications of service A if both services go down. >> > > This is expected behaviour. If A is truly dependant on B, then A will > turn into a non-ok state of its own volition rather than as a result > of any dependency magic. Dependencies are designed as a means of > suppressing notifications. Otherwise, you would *always* get a > notification for B first, and a minute or so later from A (actually, > without the dependency you could get from A first). > >> Is there a way to do what I'm trying to do here? I'd have thought it >> would be logical that if a service depends on another service and the >> service depended on dies then all services depending on it would fail >> their checks as well, but there;s probably some scenario where it >> doesn't work so well. I've had a look through the mailing list >> archives and found someone had asked a similar question to the >> nagios-devel list about 2.5 years ago and didn't end up getting an >> answer, so I thought I might ask whether solutions to this type of >> problem had been developed since then. >> > > They haven't. You're using dependencies the wrong way, really. If > A is truly dependent on B and doesn't go into a non-ok state after > B has crashed, then your check isn't doing what it's supposed to do, > or you've misunderstood the relationship somehow. > > If you were to explain what the two services actually are, it would > be easier to point you to a solution that works. > > -- > Andreas Ericsson andreas.erics...@op5.se > OP5 AB www.op5.se > Tel: +46 8-230225 Fax: +46 8-230231 > > Considering the successes of the wars on alcohol, poverty, drugs and > terror, I think we should give some serious thought to declaring war > on peace. > Well basically I have a map (similar to Google Maps) embedded in a website, which hits a URL to retrieve maps. So I have one check using check_http to check that the website itself is up and another check on that URL to make sure that the map service is available. Now if the map service goes down, the website is still up but the maps won't appear, which means the website's functionality is significantly affected. However, it is still up and viewable so doing a check on the website URL still passes. Now of course I could just write a script or something to check both URLs and set that as the check command. There is a problem for me with this approach, however, because I have some other instances where a web service depends on other web services. When I want to use these services in websites, I'd then have to write a check for each script, each containing every service in the chain that is needed to display the website correctly. This way of doing things just seems a bit repetitive to me, especially when I have a check for these web services already. -- ___ 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] Dependent service checks don't fail when depended-on service check fails
Jarrod Moore wrote: > Hello everyone, > > I have a couple of related questions regarding service dependencies in > Nagios and their limitations. I have two service checks (let's call > them A and B) and service A depends on service B to function > correctly. I want to set Nagios up so that if service B crashes then > both services A and B are put into the critical state in Nagios. I've > tried using service dependencies in Nagios to represent this behaviour > but have yet to be successful. I can only get it to suppress > notifications of service A if both services go down. > This is expected behaviour. If A is truly dependant on B, then A will turn into a non-ok state of its own volition rather than as a result of any dependency magic. Dependencies are designed as a means of suppressing notifications. Otherwise, you would *always* get a notification for B first, and a minute or so later from A (actually, without the dependency you could get from A first). > Is there a way to do what I'm trying to do here? I'd have thought it > would be logical that if a service depends on another service and the > service depended on dies then all services depending on it would fail > their checks as well, but there;s probably some scenario where it > doesn't work so well. I've had a look through the mailing list > archives and found someone had asked a similar question to the > nagios-devel list about 2.5 years ago and didn't end up getting an > answer, so I thought I might ask whether solutions to this type of > problem had been developed since then. > They haven't. You're using dependencies the wrong way, really. If A is truly dependent on B and doesn't go into a non-ok state after B has crashed, then your check isn't doing what it's supposed to do, or you've misunderstood the relationship somehow. If you were to explain what the two services actually are, it would be easier to point you to a solution that works. -- Andreas Ericsson andreas.erics...@op5.se OP5 AB www.op5.se Tel: +46 8-230225 Fax: +46 8-230231 Considering the successes of the wars on alcohol, poverty, drugs and terror, I think we should give some serious thought to declaring war on peace. -- ___ 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] Dependent service checks don't fail when depended-on service check fails
Hello everyone, I have a couple of related questions regarding service dependencies in Nagios and their limitations. I have two service checks (let's call them A and B) and service A depends on service B to function correctly. I want to set Nagios up so that if service B crashes then both services A and B are put into the critical state in Nagios. I've tried using service dependencies in Nagios to represent this behaviour but have yet to be successful. I can only get it to suppress notifications of service A if both services go down. Is there a way to do what I'm trying to do here? I'd have thought it would be logical that if a service depends on another service and the service depended on dies then all services depending on it would fail their checks as well, but there;s probably some scenario where it doesn't work so well. I've had a look through the mailing list archives and found someone had asked a similar question to the nagios-devel list about 2.5 years ago and didn't end up getting an answer, so I thought I might ask whether solutions to this type of problem had been developed since then. Cheers, Jarrod -- ___ 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
