Re: Hard limits in Tomcat?
Dear Leon, Oh, don't be so dramatic. There is a whole world out there of smaller companies that have one or two Tomcat servers in production, running on the cheapest shared server environment they could find. This product targets companies that have two or three developers, one of whom has been pressed into doing the admin role on the side. yes, but why should they give their very sensitive data into the hand of someone? You understand that tomcat operation profile provides perfect opportunity for a potential attacker or competitor? Especially when there are tools which does the same without giving the data away. I see, so you are saying that Tomcat's JMX stats are very sensitive. Is that true in all cases? For each and every running instance of Tomcat? This is basically the same discussion as is currently raging between using internal mail servers and using Google's. I note that both you and I are using Google mail. Some company policies forbid the use of external mail systems precisely for the reasons you suggest. I've even worked at companies that firewalled hotmail.com to keep their employees off of it. Other companies decide to outsource all of their mail services to Google for the convenience and savings it offers. I apologize if the operational model of Java-monitor startled you. That was not my intention. It works this way because that takes the care and feeding of the monitoring platform away from the user. Some people like that while others, such as yourself, prefer not to work like this. Why dont you just supply another web/app which collects the data locally in the customers environment? Well, it's kind'a hard to send out an e-mail message that your app server has died, when the monitor is running inside that very same server. Also, I have plans for rules processing that should help predict server death. I'm not sure everyone will want to have the overhead of such processing in their operational environment. I'm not asking anyone to switch away from their existing tools. I'm certainly not suggesting that you use it, as Java-monitor is clearly not suited for your environment. -- Kees Jan http://java-monitor.com/forum/ [EMAIL PROTECTED] 06-51838192 Human beings make life so interesting. Do you know that in a universe so full of wonders, they have managed to invent boredom. Quite astonishing... -- Terry Partchett - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Hard limits in Tomcat?
Dear Chris, I am setting up a monitoring system for Tomcat servers and I am looking for hard limits in Tomcat servers in general. I found a few so far: file descriptors, memory pools (ok, these are jdk limits) and thread pools. Are there any other hard limits that I can run into? I would call these soft limits, as they can be changed. Ah, sorry for the confusion. I should have asked for limits that are hard at run-time. Thread pool sizes may be editable, but they are fixed once Tomcat runs. What limits are relevant? For instance, Java doesn't allow you to have any method with more than 64k of code. I suppose that's of little consequence to a running JVM, since the code would never be loaded. Yes, I ran into that limit for a generated servlet once. This is not the kind of limit that I am looking for, as it is caught compile-time, not run-time. If you are going to count memory (heap?) and file descriptors, I suppose you could also count CPU time, since that is a limitable resource on *NIX systems. Hmm. It's really only useful if I can monitor both the maximum available time and the used time. I have no idea how I would measure that, even at unix level. It gets even more messy in virtual servers. If you really are talking about soft limits, then you probably also want to see the number of requests accepted but not yet being handled (controlled by the Connector's acceptCount attribute), the number of request processors (is this thread pools above?), the number of connections total/available/used in JDBC connection pools. Ah, that is interesting too: queue fill levels that should under normal circumstances be more or less empty. Much like the ObjectPendingFinalizationCount. Thanks for that. How would I use it, though? In my Tomcat acceptCount has a value of 100. That's probaly an upper limit. What is the 'un-use' property that goes with this upper limit? What MBean can I talk to about JDBC connection pooling? -- Kees Jan http://java-monitor.com/forum/ [EMAIL PROTECTED] 06-51838192 Human beings make life so interesting. Do you know that in a universe so full of wonders, they have managed to invent boredom. Quite astonishing... -- Terry Partchett - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Hard limits in Tomcat?
I think the question you wanna ask yourself first is, do you want to monitor tomcat or do you want to monitor your application? regards Leon On Wed, Nov 19, 2008 at 3:18 PM, Kees Jan Koster [EMAIL PROTECTED] wrote: Dear Chris, I am setting up a monitoring system for Tomcat servers and I am looking for hard limits in Tomcat servers in general. I found a few so far: file descriptors, memory pools (ok, these are jdk limits) and thread pools. Are there any other hard limits that I can run into? I would call these soft limits, as they can be changed. Ah, sorry for the confusion. I should have asked for limits that are hard at run-time. Thread pool sizes may be editable, but they are fixed once Tomcat runs. What limits are relevant? For instance, Java doesn't allow you to have any method with more than 64k of code. I suppose that's of little consequence to a running JVM, since the code would never be loaded. Yes, I ran into that limit for a generated servlet once. This is not the kind of limit that I am looking for, as it is caught compile-time, not run-time. If you are going to count memory (heap?) and file descriptors, I suppose you could also count CPU time, since that is a limitable resource on *NIX systems. Hmm. It's really only useful if I can monitor both the maximum available time and the used time. I have no idea how I would measure that, even at unix level. It gets even more messy in virtual servers. If you really are talking about soft limits, then you probably also want to see the number of requests accepted but not yet being handled (controlled by the Connector's acceptCount attribute), the number of request processors (is this thread pools above?), the number of connections total/available/used in JDBC connection pools. Ah, that is interesting too: queue fill levels that should under normal circumstances be more or less empty. Much like the ObjectPendingFinalizationCount. Thanks for that. How would I use it, though? In my Tomcat acceptCount has a value of 100. That's probaly an upper limit. What is the 'un-use' property that goes with this upper limit? What MBean can I talk to about JDBC connection pooling? -- Kees Jan http://java-monitor.com/forum/ [EMAIL PROTECTED] 06-51838192 Human beings make life so interesting. Do you know that in a universe so full of wonders, they have managed to invent boredom. Quite astonishing... -- Terry Partchett - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Hard limits in Tomcat?
Dear Leon, I think the question you wanna ask yourself first is, do you want to monitor tomcat or do you want to monitor your application? I want to monitor Tomcat, not the application. I'm using the information to improve the Tomcat monitoring on Java-monitor.com. Currently you can see the memory pools/thread pools/file descriptors and their limits. I was just curious if there are any other pool-like structures inside Tomcat. I'm sure that there are many applications out there that have pools and limits, but Java-monitor works for all Tomcats. -- Kees Jan http://java-monitor.com/forum/ [EMAIL PROTECTED] 06-51838192 The secret of success lies in the stability of the goal. -- Benjamin Disraeli - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Hard limits in Tomcat?
is there a demo available on the java-monitor.com? sofar i only find a php forum :-) Leon On Wed, Nov 19, 2008 at 3:31 PM, Kees Jan Koster [EMAIL PROTECTED] wrote: Dear Leon, I think the question you wanna ask yourself first is, do you want to monitor tomcat or do you want to monitor your application? I want to monitor Tomcat, not the application. I'm using the information to improve the Tomcat monitoring on Java-monitor.com. Currently you can see the memory pools/thread pools/file descriptors and their limits. I was just curious if there are any other pool-like structures inside Tomcat. I'm sure that there are many applications out there that have pools and limits, but Java-monitor works for all Tomcats. -- Kees Jan http://java-monitor.com/forum/ [EMAIL PROTECTED] 06-51838192 The secret of success lies in the stability of the goal. -- Benjamin Disraeli - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Hard limits in Tomcat?
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Keen Jan, Kees Jan Koster wrote: Ah, sorry for the confusion. I should have asked for limits that are hard at run-time. Thread pool sizes may be editable, but they are fixed once Tomcat runs. Gotcha. Hard runtime limits makes a whole lot more sense. Sorry for not jumping to that obvious conclusion. I wasn't trying to be a jerk ;) What limits are relevant? For instance, Java doesn't allow you to have any method with more than 64k of code. I suppose that's of little consequence to a running JVM, since the code would never be loaded. Yes, I ran into that limit for a generated servlet once. This is not the kind of limit that I am looking for, as it is caught compile-time, not run-time. Yup: one big, nasty JSP will get you some day. If you are going to count memory (heap?) and file descriptors, I suppose you could also count CPU time, since that is a limitable resource on *NIX systems. Hmm. It's really only useful if I can monitor both the maximum available time and the used time. I have no idea how I would measure that, even at unix level. It gets even more messy in virtual servers. I don't see why virtual servers would be trickier: the kernel should be counting beans properly. In terms of getting that information, you need to call getrlimit to see what the limit is. I'm not sure where to get the current resource usage, though. If you really are talking about soft limits, then you probably also want to see the number of requests accepted but not yet being handled (controlled by the Connector's acceptCount attribute), the number of request processors (is this thread pools above?), the number of connections total/available/used in JDBC connection pools. Ah, that is interesting too: queue fill levels that should under normal circumstances be more or less empty. Much like the ObjectPendingFinalizationCount. Thanks for that. How would I use it, though? In my Tomcat acceptCount has a value of 100. That's probaly an upper limit. What is the 'un-use' property that goes with this upper limit? Do you mean something like a minimum accept count? By definition, the minimum accept count is 0, since you're talking about the number of connections that the socket will accept. It can certainly always be zero. But this is an OS thing, and is set when you bind to the socket. I don't think there's a way to change this through Java after the socket has been bound. What MBean can I talk to about JDBC connection pooling? You should get yourself a copy of LabmdaProbe and basically steal all that code. Better yet, just use LambdaProbe and save yourself a lot of headache. I'm sure they'd appreciate any code you'd like to donate to the project to sniff other limits (like file descriptors). - -chris -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.9 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAkkkJikACgkQ9CaO5/Lv0PBuXQCeKp58nHImA6fWFpQmwL59+h9l uqkAoMKrYz4eRVN8rt57KzPcwVlzQFIM =P2f6 -END PGP SIGNATURE- - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Hard limits in Tomcat?
Dear Leon, is there a demo available on the java-monitor.com? sofar i only find a php forum :-) The forum has the monitoring tool built-in. A bit weird at forst, but it makes it really simple to post questions, as you can just post graphs from the tool right on the forum. No need to make screenshots. If you register and log in, the tool shows up. I have not put any screenshots hi-res on-line yet. I have only two hands. :-( I should do that. Here are some low-res ones: http://java-monitor.com/forum/showthread.php?t=123 -- Kees Jan http://java-monitor.com/forum/ [EMAIL PROTECTED] 06-51838192 The secret of success lies in the stability of the goal. -- Benjamin Disraeli -- Kees Jan http://java-monitor.com/forum/ [EMAIL PROTECTED] 06-51838192 Rule 1 for being in a hole: stop digging. - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Hard limits in Tomcat?
Dear Chris, Ah, sorry for the confusion. I should have asked for limits that are hard at run-time. Thread pool sizes may be editable, but they are fixed once Tomcat runs. Gotcha. Hard runtime limits makes a whole lot more sense. Sorry for not jumping to that obvious conclusion. I wasn't trying to be a jerk ;) Don't worry. Better to ask for clarification than to assume. I wish more people would follow your example. If you are going to count memory (heap?) and file descriptors, I suppose you could also count CPU time, since that is a limitable resource on *NIX systems. Hmm. It's really only useful if I can monitor both the maximum available time and the used time. I have no idea how I would measure that, even at unix level. It gets even more messy in virtual servers. I don't see why virtual servers would be trickier: the kernel should be counting beans properly. In terms of getting that information, you need to call getrlimit to see what the limit is. I'm not sure where to get the current resource usage, though. Hmmyeah. We're way off into OS-land here. Virtual servers get esepcially tricky when a few are running on a host and you're in one of them. You may still be able to measure your own cpu usage, but you have no idea at all how much was available. So you can never tell if you're using what is available or not. I run Java- monitor's components on the bare iron for that very reason. So that I can see what uses the cpu and optimise the right places. If you really are talking about soft limits, then you probably also want to see the number of requests accepted but not yet being handled (controlled by the Connector's acceptCount attribute), the number of request processors (is this thread pools above?), the number of connections total/available/used in JDBC connection pools. Ah, that is interesting too: queue fill levels that should under normal circumstances be more or less empty. Much like the ObjectPendingFinalizationCount. Thanks for that. How would I use it, though? In my Tomcat acceptCount has a value of 100. That's probaly an upper limit. What is the 'un-use' property that goes with this upper limit? Do you mean something like a minimum accept count? By definition, the minimum accept count is 0, since you're talking about the number of connections that the socket will accept. It can certainly always be zero. But this is an OS thing, and is set when you bind to the socket. I don't think there's a way to change this through Java after the socket has been bound. Grr. Off into OS-land again. Oh well. :-) What MBean can I talk to about JDBC connection pooling? You should get yourself a copy of LabmdaProbe and basically steal all that code. Better yet, just use LambdaProbe and save yourself a lot of headache. I'm sure they'd appreciate any code you'd like to donate to the project to sniff other limits (like file descriptors). Yes, LambdaProbe sure looks nice. My probe code is available from Google code (http://code.google.com/p/java-monitor-probes/) but really all I do so query JMX mbeans. Hmm. Maybe I should talk to the devs of the new default connection pool to incorporate a pool MBean too. That's useful for all of us, regardless of monitoring tool in use. For Java-monitor I have to keep in mind that I cannot do anything invasive. I want the probe to be so lightweigth that installation is a mere 5 minutes work and has no measurable impact on the JVM's run-time performance. -- Kees Jan http://java-monitor.com/forum/ [EMAIL PROTECTED] 06-51838192 Human beings make life so interesting. Do you know that in a universe so full of wonders, they have managed to invent boredom. Quite astonishing... -- Terry Partchett -- Kees Jan http://java-monitor.com/forum/ [EMAIL PROTECTED] 06-51838192 The secret of success lies in the stability of the goal. -- Benjamin Disraeli - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Hard limits in Tomcat?
well, downloaded, installed, started, klicked, ... deleted... you should announce that your war is SENDING DATA to the central server in LARGE letters :-) which users are you targeting? No one i know (and i'm in the webapp business for about 10 years) will ever going to use this stuff, since its opposes all security guidelines which exists in the real applications world, without considering if its useful or not. It may sound a bit harsh, but any admin who installs java-monitor webapp on companies server should be fired at once (and probably will be). regards Leon On Wed, Nov 19, 2008 at 4:27 PM, Kees Jan Koster [EMAIL PROTECTED] wrote: Dear Leon, is there a demo available on the java-monitor.com? sofar i only find a php forum :-) The forum has the monitoring tool built-in. A bit weird at forst, but it makes it really simple to post questions, as you can just post graphs from the tool right on the forum. No need to make screenshots. If you register and log in, the tool shows up. I have not put any screenshots hi-res on-line yet. I have only two hands. :-( I should do that. Here are some low-res ones: http://java-monitor.com/forum/showthread.php?t=123 - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Hard limits in Tomcat?
Better yet do you want to know how the application uses Tomcat resources? To do what Leon mentions requires a profilier that is approved for production use or have the developers write timers in the code for critical measurements say around time it takes for a request versus jdbc calls some may have to be an aggragate of many calls if that is what is happening like say 1000 calls to get data for one servlet method request. If you can have measurements around the edge of your app and servlet container measuements you should bet set for isolating performance issues for some time. Regards, -Tony --- On Wed, 11/19/08, Leon Rosenberg [EMAIL PROTECTED] wrote: From: Leon Rosenberg [EMAIL PROTECTED] Subject: Re: Hard limits in Tomcat? To: Tomcat Users List users@tomcat.apache.org Date: Wednesday, November 19, 2008, 7:23 AM I think the question you wanna ask yourself first is, do you want to monitor tomcat or do you want to monitor your application? regards Leon On Wed, Nov 19, 2008 at 3:18 PM, Kees Jan Koster [EMAIL PROTECTED] wrote: Dear Chris, I am setting up a monitoring system for Tomcat servers and I am looking for hard limits in Tomcat servers in general. I found a few so far: file descriptors, memory pools (ok, these are jdk limits) and thread pools. Are there any other hard limits that I can run into? I would call these soft limits, as they can be changed. Ah, sorry for the confusion. I should have asked for limits that are hard at run-time. Thread pool sizes may be editable, but they are fixed once Tomcat runs. What limits are relevant? For instance, Java doesn't allow you to have any method with more than 64k of code. I suppose that's of little consequence to a running JVM, since the code would never be loaded. Yes, I ran into that limit for a generated servlet once. This is not the kind of limit that I am looking for, as it is caught compile-time, not run-time. If you are going to count memory (heap?) and file descriptors, I suppose you could also count CPU time, since that is a limitable resource on *NIX systems. Hmm. It's really only useful if I can monitor both the maximum available time and the used time. I have no idea how I would measure that, even at unix level. It gets even more messy in virtual servers. If you really are talking about soft limits, then you probably also want to see the number of requests accepted but not yet being handled (controlled by the Connector's acceptCount attribute), the number of request processors (is this thread pools above?), the number of connections total/available/used in JDBC connection pools. Ah, that is interesting too: queue fill levels that should under normal circumstances be more or less empty. Much like the ObjectPendingFinalizationCount. Thanks for that. How would I use it, though? In my Tomcat acceptCount has a value of 100. That's probaly an upper limit. What is the 'un-use' property that goes with this upper limit? What MBean can I talk to about JDBC connection pooling? -- Kees Jan http://java-monitor.com/forum/ [EMAIL PROTECTED] 06-51838192 Human beings make life so interesting. Do you know that in a universe so full of wonders, they have managed to invent boredom. Quite astonishing... -- Terry Partchett - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Hard limits in Tomcat?
Dear Leon, well, downloaded, installed, started, klicked, ... deleted... you should announce that your war is SENDING DATA to the central server in LARGE letters :-) which users are you targeting? No one i know (and i'm in the webapp business for about 10 years) will ever going to use this stuff, since its opposes all security guidelines which exists in the real applications world, without considering if its useful or not. It may sound a bit harsh, but any admin who installs java-monitor webapp on companies server should be fired at once (and probably will be). Oh, don't be so dramatic. There is a whole world out there of smaller companies that have one or two Tomcat servers in production, running on the cheapest shared server environment they could find. This product targets companies that have two or three developers, one of whom has been pressed into doing the admin role on the side. I apologize if the operational model of Java-monitor startled you. That was not my intention. It works this way because that takes the care and feeding of the monitoring platform away from the user. Some people like that while others, such as yourself, prefer not to work like this. Even in large companies, Java-monitor has its place. I spoke to one of my users this week and he tells me that he uses Java-monitor on the test machine because the process of getting JBoss performance statistics out of their hosting company takes days. I like it because I can check the status of my servers from my iPhone. -- Kees Jan http://java-monitor.com/forum/ [EMAIL PROTECTED] 06-51838192 Rule 1 for being in a hole: stop digging. - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Hard limits in Tomcat?
Hello Kees Jan, On Wed, Nov 19, 2008 at 8:25 PM, Kees Jan Koster [EMAIL PROTECTED] wrote: Dear Leon, Oh, don't be so dramatic. There is a whole world out there of smaller companies that have one or two Tomcat servers in production, running on the cheapest shared server environment they could find. This product targets companies that have two or three developers, one of whom has been pressed into doing the admin role on the side. yes, but why should they give their very sensitive data into the hand of someone? You understand that tomcat operation profile provides perfect opportunity for a potential attacker or competitor? Especially when there are tools which does the same without giving the data away. I apologize if the operational model of Java-monitor startled you. That was not my intention. It works this way because that takes the care and feeding of the monitoring platform away from the user. Some people like that while others, such as yourself, prefer not to work like this. Why dont you just supply another web/app which collects the data locally in the customers environment? Even in large companies, Java-monitor has its place. I spoke to one of my users this week and he tells me that he uses Java-monitor on the test machine because the process of getting JBoss performance statistics out of their hosting company takes days. I like it because I can check the status of my servers from my iPhone. Again, there are tools which perform the same or more without giving the data to potential competitor or hacker. Check lambdaprobe (tomcat level) or moskito (application level). Regards Leon - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Hard limits in Tomcat?
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Kees Jan, Kees Jan Koster wrote: I am setting up a monitoring system for Tomcat servers and I am looking for hard limits in Tomcat servers in general. I found a few so far: file descriptors, memory pools (ok, these are jdk limits) and thread pools. Are there any other hard limits that I can run into? I would call these soft limits, as they can be changed. What limits are relevant? For instance, Java doesn't allow you to have any method with more than 64k of code. I suppose that's of little consequence to a running JVM, since the code would never be loaded. If you are going to count memory (heap?) and file descriptors, I suppose you could also count CPU time, since that is a limitable resource on *NIX systems. If you really are talking about soft limits, then you probably also want to see the number of requests accepted but not yet being handled (controlled by the Connector's acceptCount attribute), the number of request processors (is this thread pools above?), the number of connections total/available/used in JDBC connection pools. Does that help? - -chris -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.9 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAkkjPLUACgkQ9CaO5/Lv0PBlYACbBopvrcbKmuHs8He1a+riMuFm mNMAoLe0/90h12/VsLEouDmIyBh2D676 =s+w0 -END PGP SIGNATURE- - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
