Re: Does tomcat support multicores
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Alan, Alan Chaney wrote: | XP Home only supports one core - however, that would hardly be an OS for | a production web server (grin) Unless XP sees an Intel ht processor as something other than two cored, this is BS. I have XP home on one of my laptops, and it happily recognized and utilizes both ht'd processors. | I would suspect that the OPs factors were related to IO Bandwidth or | running out of threads as suggested earlier. I've found that a modern | multicore machine doesn't actually spend very much time processing the | Tomcat stuff at all. That's because CPUs are ridiculously fast these days compared to the hardware with which they are coupled. Bus and memory speeds are disappointingly low, which is where the real time is wasted. :( - -chris -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.8 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAkfIElkACgkQ9CaO5/Lv0PCyxwCfYpAN76N8SYAerozE5gaHWcfG xuAAn1DObFinHiVdIeqpubawAFgaxoHc =YO97 -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: Does tomcat support multicores
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Len, Len Popp wrote: | (Please excuse the boring licensing details, but I've seen a lot of | misinformation on this topic.) Thanks for setting the record straight. I didn't want to call Alan a liar, but I knew that his assertions were in conflict with my experience. - -chris -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.8 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAkfIEqUACgkQ9CaO5/Lv0PCjHACgmRq4HB0DAf+NX9X0WNsbtCib nAsAoIOHPPctspaQb6Uxh32cC+T/az7/ =cFgv -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]
Does tomcat support multicores
Os - WinXP CPU - Intel Quad Core Hi I'm running a tomcat server, and would like to know if Tomcat can make use of multiple cores? When I max the server out, all 4 cores see little usage however the java process never uses more than 25%. So this makes me believe that Tomcat does not make use of a multicore system. Would I benefit from running more than one instance and setup load bearing between the two? Thanks James Law Search all of our current vacancies at www.generic-software.com The information contained within this message is intended for the addressee only and may contain confidential and/or privileged information. If you are not the addressee, please delete this message and notify the sender - you should not copy, distribute or disclose its contents to other parties. Any images, documents, views or opinions expressed in this message are those of the sender and do not necessarily represent those of Generic Software Consultants Ltd or any of its affiliates. No reliance may be placed on this message without written confirmation from an authorised company representative, and no actions should be taken based on its contents. Generic Software Consultants Ltd Registered in England No. 2830109 @ St. Andrews House, Caldecotte Lake Drive, Caldecotte Business Park, Milton Keynes. MK7 8LE Tel: 01908 278450 VAT Registered No: 608 6625 28
Re: Does tomcat support multicores
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 James, James Law wrote: | Os - WinXP | | CPU - Intel Quad Core | | Hi I'm running a tomcat server, and would like to know if Tomcat can | make use of multiple cores? When I max the server out, all 4 cores see | little usage however the java process never uses more than 25%. Sounds like you haven't really maxed-out your server. What is your definition of maxed-out? | So this makes me believe that Tomcat does not make use of a multicore | system. Just like most hardware resource questions in Tomcat, it all comes down to the JVM + the OS. Tomcat itself neither enables nor disables this capability. The JVM supports multiple threads. The OS supports threads. Presumably, the OS is smart enough to allow threads from a single process to run on any CPU (or core). | Would I benefit from running more than one instance and setup load | bearing between the two? Probably not. I would venture a guess that you are seeing appropriate resource usage for your load scenario. What does maxed-out mean, and why do you think you are in that state? Can you see which processor(s) is(are) running java.exe (or whatever) processes, or are you just looking at the overall CPU-usage meter and seeing that it shows 25% total CPU usage? There's also the possibility that your application is I/O-bound instead of CPU bound, meaning that the CPU is spending most of the time waiting around for data to move around instead of performing calculations and whatnot. That wouldn't be a surprise given that network transfer speeds are relatively slow compared to bus speeds and the rate at which your CPU(s) can process information. - -chris -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.8 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAkfG2xgACgkQ9CaO5/Lv0PARPACePFKMUrk6BWYH6Ym2sAsMtAmR VfwAn0/nesfQGN0I1NipHbuSY9dMyJl6 =wnSS -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: Does tomcat support multicores
From: James Law [mailto:[EMAIL PROTECTED] Subject: Does tomcat support multicores Hi I'm running a tomcat server, and would like to know if Tomcat can make use of multiple cores? Of course - assuming your JVM does (and any modern JVM does - but you didn't bother to mention which one you're using). The fact that you're not seeing much CPU utilization simply means your tests are limited by something else, such as I/O or database access. - Chuck THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE PROPRIETARY MATERIAL and is thus for use only by the intended recipient. If you received this in error, please contact the sender and delete the e-mail and its attachments from all computers. - 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: Does tomcat support multicores
From: Caldarale, Charles R Subject: RE: Does tomcat support multicores From: James Law [mailto:[EMAIL PROTECTED] Subject: Does tomcat support multicores Hi I'm running a tomcat server, and would like to know if Tomcat can make use of multiple cores? Of course - assuming your JVM does And your OS. Doesn't XP limit itself to two cores? - Chuck THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE PROPRIETARY MATERIAL and is thus for use only by the intended recipient. If you received this in error, please contact the sender and delete the e-mail and its attachments from all computers. - 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: Does tomcat support multicores
It works just fine! My guess would be that the load you're putting on it is single threaded, so there's only a single thread executing on the server. You're really only asking it to do one thing at a time. Make sure that you're running multiple concurrent loads. -Original Message- From: Christopher Schultz [mailto:[EMAIL PROTECTED] Sent: Thursday, February 28, 2008 11:03 AM To: Tomcat Users List Subject: Re: Does tomcat support multicores -BEGIN PGP SIGNED MESSAGE- Hash: SHA1 James, James Law wrote: | Os - WinXP | | CPU - Intel Quad Core | | Hi I'm running a tomcat server, and would like to know if Tomcat can | make use of multiple cores? When I max the server out, all 4 cores see | little usage however the java process never uses more than 25%. Sounds like you haven't really maxed-out your server. What is your definition of maxed-out? | So this makes me believe that Tomcat does not make use of a multicore | system. Just like most hardware resource questions in Tomcat, it all comes down to the JVM + the OS. Tomcat itself neither enables nor disables this capability. The JVM supports multiple threads. The OS supports threads. Presumably, the OS is smart enough to allow threads from a single process to run on any CPU (or core). | Would I benefit from running more than one instance and setup load | bearing between the two? Probably not. I would venture a guess that you are seeing appropriate resource usage for your load scenario. What does maxed-out mean, and why do you think you are in that state? Can you see which processor(s) is(are) running java.exe (or whatever) processes, or are you just looking at the overall CPU-usage meter and seeing that it shows 25% total CPU usage? There's also the possibility that your application is I/O-bound instead of CPU bound, meaning that the CPU is spending most of the time waiting around for data to move around instead of performing calculations and whatnot. That wouldn't be a surprise given that network transfer speeds are relatively slow compared to bus speeds and the rate at which your CPU(s) can process information. - -chris -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.8 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAkfG2xgACgkQ9CaO5/Lv0PARPACePFKMUrk6BWYH6Ym2sAsMtAmR VfwAn0/nesfQGN0I1NipHbuSY9dMyJl6 =wnSS -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: Does tomcat support multicores
We use a program called WAPT to ramp up the amount of requests sent to Tomcat, probably not the best way going off what has been said. It got to the point were it the Java process never go above 25% cpu usage while the memory usage increases accordingly. Which is why I assumed it would not making proper use of the cores. Currently using Java 1.6. -Original Message- From: Christopher Schultz [mailto:[EMAIL PROTECTED] Sent: 28 February 2008 16:03 To: Tomcat Users List Subject: Re: Does tomcat support multicores -BEGIN PGP SIGNED MESSAGE- Hash: SHA1 James, James Law wrote: | Os - WinXP | | CPU - Intel Quad Core | | Hi I'm running a tomcat server, and would like to know if Tomcat can | make use of multiple cores? When I max the server out, all 4 cores see | little usage however the java process never uses more than 25%. Sounds like you haven't really maxed-out your server. What is your definition of maxed-out? | So this makes me believe that Tomcat does not make use of a multicore | system. Just like most hardware resource questions in Tomcat, it all comes down to the JVM + the OS. Tomcat itself neither enables nor disables this capability. The JVM supports multiple threads. The OS supports threads. Presumably, the OS is smart enough to allow threads from a single process to run on any CPU (or core). | Would I benefit from running more than one instance and setup load | bearing between the two? Probably not. I would venture a guess that you are seeing appropriate resource usage for your load scenario. What does maxed-out mean, and why do you think you are in that state? Can you see which processor(s) is(are) running java.exe (or whatever) processes, or are you just looking at the overall CPU-usage meter and seeing that it shows 25% total CPU usage? There's also the possibility that your application is I/O-bound instead of CPU bound, meaning that the CPU is spending most of the time waiting around for data to move around instead of performing calculations and whatnot. That wouldn't be a surprise given that network transfer speeds are relatively slow compared to bus speeds and the rate at which your CPU(s) can process information. - -chris - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] Search all of our current vacancies at www.generic-software.com The information contained within this message is intended for the addressee only and may contain confidential and/or privileged information. If you are not the addressee, please delete this message and notify the sender - you should not copy, distribute or disclose its contents to other parties. Any images, documents, views or opinions expressed in this message are those of the sender and do not necessarily represent those of Generic Software Consultants Ltd or any of its affiliates. No reliance may be placed on this message without written confirmation from an authorised company representative, and no actions should be taken based on its contents. Generic Software Consultants Ltd Registered in England No. 2830109 @ St. Andrews House, Caldecotte Lake Drive, Caldecotte Business Park, Milton Keynes. MK7 8LE Tel: 01908 278450 VAT Registered No: 608 6625 28
Re: Does tomcat support multicores
tomcat is core agnostic, it lets the JVM handle it, and the answer is yes, most JVMs will support multi core machines Filip James Law wrote: Os - WinXP CPU - Intel Quad Core Hi I'm running a tomcat server, and would like to know if Tomcat can make use of multiple cores? When I max the server out, all 4 cores see little usage however the java process never uses more than 25%. So this makes me believe that Tomcat does not make use of a multicore system. Would I benefit from running more than one instance and setup load bearing between the two? Thanks James Law Search all of our current vacancies at www.generic-software.com The information contained within this message is intended for the addressee only and may contain confidential and/or privileged information. If you are not the addressee, please delete this message and notify the sender - you should not copy, distribute or disclose its contents to other parties. Any images, documents, views or opinions expressed in this message are those of the sender and do not necessarily represent those of Generic Software Consultants Ltd or any of its affiliates. No reliance may be placed on this message without written confirmation from an authorised company representative, and no actions should be taken based on its contents. Generic Software Consultants Ltd Registered in England No. 2830109 @ St. Andrews House, Caldecotte Lake Drive, Caldecotte Business Park, Milton Keynes. MK7 8LE Tel: 01908 278450 VAT Registered No: 608 6625 28 No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.516 / Virus Database: 269.21.1/1302 - Release Date: 2/27/2008 4:34 PM - 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: Does tomcat support multicores
What kind of work is Tomcat doing for each request that WAPT sends in? For example, if you were doing something that had to go back to a database, and you had a bad sync block in your code somewhere, or didn't have enough connections in your DB pool, that could cause it to behave like it is single threaded - because all of the threads / cores are contending for some shared resource. Or, if you are just serving pages, perhaps you are disk bound, and your disk drive just isn't fast enough. Or, perhaps you have reached the limit of how much load WAPT can generate. There are lots of avenues to explore here, but they are all implementation specific. Dan - 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: Does tomcat support multicores
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 James, James Law wrote: | We use a program called WAPT to ramp up the amount of requests sent | to Tomcat, probably not the best way going off what has been said. It | got to the point were it the Java process never go above 25% cpu | usage while the memory usage increases accordingly. Which is why I | assumed it would not making proper use of the cores. Currently using | Java 1.6. How many concurrent connections was that relative to the maximum connections your Connector will accept? It's possible you've just exhausted your connection pool, and the machine simply will not accept more work to do. This is a good position to be in ;) - -chris -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.8 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAkfHE50ACgkQ9CaO5/Lv0PBy5QCbBdJJ8SdfCpWPYdhbQydlstWa DZMAoJ+1JXluDBBykqdM9yTbQCthw+2c =/AQr -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: Does tomcat support multicores
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Chuck, Caldarale, Charles R wrote: | From: Caldarale, Charles R | Subject: RE: Does tomcat support multicores | | From: James Law [mailto:[EMAIL PROTECTED] | Subject: Does tomcat support multicores | | Hi I'm running a tomcat server, and would like to know if Tomcat can | make use of multiple cores? | Of course - assuming your JVM does | | And your OS. Doesn't XP limit itself to two cores? I don't think so. And if it does, it certainly does different things based upon the packaging of the OS you got -- like server versus home or whatever. - -chris -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.8 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAkfHE/UACgkQ9CaO5/Lv0PD+zgCeOuojLm48BSrET1mlysJtf+K0 pyIAoMGnywDMOXLddlXN4v1uw43wB0Eb =rAwX -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: Does tomcat support multicores
From: Christopher Schultz [mailto:[EMAIL PROTECTED] Subject: Re: Does tomcat support multicores | Doesn't XP limit itself to two cores? I don't think so. I'm sure some versions of XP are limited to two CPUs, since that was a concern when HyperThreading was all the rage. It may be just the Home edition, rather than Pro. I know the Windows Server versions (different license than XP) all support at least four CPUs. - Chuck THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE PROPRIETARY MATERIAL and is thus for use only by the intended recipient. If you received this in error, please contact the sender and delete the e-mail and its attachments from all computers. - 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: Does tomcat support multicores
XP Home only supports one core - however, that would hardly be an OS for a production web server (grin) XP Professional is limited to 2 cpus I would suspect that the OPs factors were related to IO Bandwidth or running out of threads as suggested earlier. I've found that a modern multicore machine doesn't actually spend very much time processing the Tomcat stuff at all. Caldarale, Charles R wrote: From: Christopher Schultz [mailto:[EMAIL PROTECTED] Subject: Re: Does tomcat support multicores | Doesn't XP limit itself to two cores? I don't think so. I'm sure some versions of XP are limited to two CPUs, since that was a concern when HyperThreading was all the rage. It may be just the Home edition, rather than Pro. I know the Windows Server versions (different license than XP) all support at least four CPUs. - Chuck THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE PROPRIETARY MATERIAL and is thus for use only by the intended recipient. If you received this in error, please contact the sender and delete the e-mail and its attachments from all computers. - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] !DSPAM:47c72002262671410093335! - 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: Does tomcat support multicores
(Please excuse the boring licensing details, but I've seen a lot of misinformation on this topic.) Microsoft Windows is licensed per-processor, not per-core. XP Home supports 1 processor and XP Pro supports 2 processors. Each processor may have multiple cores. Server versions can support more than 2 processors but you pay for them. (Vista works similarly.) I've got a machine running Windows XP Home with 2 cores (Athlon X2) and it definitely uses both cores. And it's running Tomcat. :-) reference: http://www.microsoft.com/licensing/highlights/multicore.mspx -- Len On Thu, Feb 28, 2008 at 4:43 PM, Alan Chaney [EMAIL PROTECTED] wrote: XP Home only supports one core - however, that would hardly be an OS for a production web server (grin) XP Professional is limited to 2 cpus I would suspect that the OPs factors were related to IO Bandwidth or running out of threads as suggested earlier. I've found that a modern multicore machine doesn't actually spend very much time processing the Tomcat stuff at all. Caldarale, Charles R wrote: From: Christopher Schultz [mailto:[EMAIL PROTECTED] Subject: Re: Does tomcat support multicores | Doesn't XP limit itself to two cores? I don't think so. I'm sure some versions of XP are limited to two CPUs, since that was a concern when HyperThreading was all the rage. It may be just the Home edition, rather than Pro. I know the Windows Server versions (different license than XP) all support at least four CPUs. - Chuck THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE PROPRIETARY MATERIAL and is thus for use only by the intended recipient. If you received this in error, please contact the sender and delete the e-mail and its attachments from all computers. - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] !DSPAM:47c72002262671410093335! - 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]