Re: Tomcat on Dual CPU Server
It would either be the JVM, but apps are usually rather ignorant of the fact that it is running on one or more CPU's, so it's probably linux. I would try and determine whether other, multi-threaded, apps only use one cpu as well, if so, then it is deffinately the OS, if other multi-threaded apps use both cpu's, then check that you are not perhaps just thinking that it is using one CPU, remember that if your webapp runs in a single thread, then it will only use one CPU. On Wed, 17 Sep 2003, Stuart Stephen wrote: Hi, I've installed tomcat on a dual CPU redhat linux 9.0 machine and have noticed that it only uses 1 cpu. How can I make it use both? Is this a linux thing or a tomcat thing? Regards, Stuart Stephen - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Tomcat on Dual CPU Server
The JVM is spec'd to be able to run on multiple processors transparently and an Java application. (Ignoring natvie code issues) Whether the *implementation* of a JVM takes advantage of a multi-cpu system is a job of the JVM vendor. -Tim Stuart Stephen wrote: Hi, I've installed tomcat on a dual CPU redhat linux 9.0 machine and have noticed that it only uses 1 cpu. How can I make it use both? Is this a linux thing or a tomcat thing? - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
RE: Tomcat on Dual CPU Server
Well, I'm using Sun 1.4.2 with Tomcat 4.1.28. I assumed that multi-threaded CPU's would be supported in Sun's Java VM. However, if i put tomcat into an infinite loop it seems to go only to just above 50% CPU for the whole system. -Original Message- From: Tim Funk [mailto:[EMAIL PROTECTED] Sent: 17 September 2003 12:49 To: Tomcat Users List Subject: Re: Tomcat on Dual CPU Server The JVM is spec'd to be able to run on multiple processors transparently and an Java application. (Ignoring natvie code issues) Whether the *implementation* of a JVM takes advantage of a multi-cpu system is a job of the JVM vendor. -Tim Stuart Stephen wrote: Hi, I've installed tomcat on a dual CPU redhat linux 9.0 machine and have noticed that it only uses 1 cpu. How can I make it use both? Is this a linux thing or a tomcat thing? - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
RE: Tomcat on Dual CPU Server
That would be correct, as I mentioned in my other mail, a single thread can only run on one CPU, thus to get to 100% cpu usage, you need at least two threads performing two concurrent infinite loops. A single loop cannot push 2 cpu's to over 50% as the one cpu will run the loop and the other will sit idle, and every now and again do some arb work. On Wed, 17 Sep 2003, Stuart Stephen wrote: Well, I'm using Sun 1.4.2 with Tomcat 4.1.28. I assumed that multi-threaded CPU's would be supported in Sun's Java VM. However, if i put tomcat into an infinite loop it seems to go only to just above 50% CPU for the whole system. -Original Message- From: Tim Funk [mailto:[EMAIL PROTECTED] Sent: 17 September 2003 12:49 To: Tomcat Users List Subject: Re: Tomcat on Dual CPU Server The JVM is spec'd to be able to run on multiple processors transparently and an Java application. (Ignoring natvie code issues) Whether the *implementation* of a JVM takes advantage of a multi-cpu system is a job of the JVM vendor. -Tim Stuart Stephen wrote: Hi, I've installed tomcat on a dual CPU redhat linux 9.0 machine and have noticed that it only uses 1 cpu. How can I make it use both? Is this a linux thing or a tomcat thing? - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Tomcat on Dual CPU Server
You need 2 infinite loops to peg a dual CPU system. -Tim Stuart Stephen wrote: Well, I'm using Sun 1.4.2 with Tomcat 4.1.28. I assumed that multi-threaded CPU's would be supported in Sun's Java VM. However, if i put tomcat into an infinite loop it seems to go only to just above 50% CPU for the whole system. -Original Message- From: Tim Funk [mailto:[EMAIL PROTECTED] Sent: 17 September 2003 12:49 To: Tomcat Users List Subject: Re: Tomcat on Dual CPU Server The JVM is spec'd to be able to run on multiple processors transparently and an Java application. (Ignoring natvie code issues) Whether the *implementation* of a JVM takes advantage of a multi-cpu system is a job of the JVM vendor. - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
RE: Tomcat on Dual CPU Server
Ahh, I wondered if that was what you meant. I'll have to experiment further. Thanks. -Original Message- From: Jaco Kroon [mailto:[EMAIL PROTECTED] Sent: 17 September 2003 12:59 To: Tomcat Users List Subject: RE: Tomcat on Dual CPU Server That would be correct, as I mentioned in my other mail, a single thread can only run on one CPU, thus to get to 100% cpu usage, you need at least two threads performing two concurrent infinite loops. A single loop cannot push 2 cpu's to over 50% as the one cpu will run the loop and the other will sit idle, and every now and again do some arb work. On Wed, 17 Sep 2003, Stuart Stephen wrote: Well, I'm using Sun 1.4.2 with Tomcat 4.1.28. I assumed that multi-threaded CPU's would be supported in Sun's Java VM. However, if i put tomcat into an infinite loop it seems to go only to just above 50% CPU for the whole system. -Original Message- From: Tim Funk [mailto:[EMAIL PROTECTED] Sent: 17 September 2003 12:49 To: Tomcat Users List Subject: Re: Tomcat on Dual CPU Server The JVM is spec'd to be able to run on multiple processors transparently and an Java application. (Ignoring natvie code issues) Whether the *implementation* of a JVM takes advantage of a multi-cpu system is a job of the JVM vendor. -Tim Stuart Stephen wrote: Hi, I've installed tomcat on a dual CPU redhat linux 9.0 machine and have noticed that it only uses 1 cpu. How can I make it use both? Is this a linux thing or a tomcat thing? - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
RE: Tomcat on Dual CPU Server
Howdy, FYI, Sun JDK 1.4.2 on Solaris 8 and 9 can use many CPUs effectively: I don't know the upper limit but I've maxed it out on 12 and 16 CPU machines that we have around here. We don't have such big linux machines so I can't explore that OS as much... How are you liking tomcat 4.1.28? ;) ;) Yoav Shapira Millennium ChemInformatics -Original Message- From: Stuart Stephen [mailto:[EMAIL PROTECTED] Sent: Wednesday, September 17, 2003 7:55 AM To: Tomcat Users List Subject: RE: Tomcat on Dual CPU Server Well, I'm using Sun 1.4.2 with Tomcat 4.1.28. I assumed that multi-threaded CPU's would be supported in Sun's Java VM. However, if i put tomcat into an infinite loop it seems to go only to just above 50% CPU for the whole system. -Original Message- From: Tim Funk [mailto:[EMAIL PROTECTED] Sent: 17 September 2003 12:49 To: Tomcat Users List Subject: Re: Tomcat on Dual CPU Server The JVM is spec'd to be able to run on multiple processors transparently and an Java application. (Ignoring natvie code issues) Whether the *implementation* of a JVM takes advantage of a multi-cpu system is a job of the JVM vendor. -Tim Stuart Stephen wrote: Hi, I've installed tomcat on a dual CPU redhat linux 9.0 machine and have noticed that it only uses 1 cpu. How can I make it use both? Is this a linux thing or a tomcat thing? - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] This e-mail, including any attachments, is a confidential business communication, and may contain information that is confidential, proprietary and/or privileged. This e-mail is intended only for the individual(s) to whom it is addressed, and may not be saved, copied, printed, disclosed or used by anyone else. If you are not the(an) intended recipient, please immediately delete this e-mail from your computer system and notify the sender. Thank you. - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
RE: Tomcat on Dual CPU Server
Whoops. 4.1.27 :oP -Original Message- From: Shapira, Yoav [mailto:[EMAIL PROTECTED] Sent: 17 September 2003 13:53 To: Tomcat Users List Subject: RE: Tomcat on Dual CPU Server Howdy, FYI, Sun JDK 1.4.2 on Solaris 8 and 9 can use many CPUs effectively: I don't know the upper limit but I've maxed it out on 12 and 16 CPU machines that we have around here. We don't have such big linux machines so I can't explore that OS as much... How are you liking tomcat 4.1.28? ;) ;) Yoav Shapira Millennium ChemInformatics -Original Message- From: Stuart Stephen [mailto:[EMAIL PROTECTED] Sent: Wednesday, September 17, 2003 7:55 AM To: Tomcat Users List Subject: RE: Tomcat on Dual CPU Server Well, I'm using Sun 1.4.2 with Tomcat 4.1.28. I assumed that multi-threaded CPU's would be supported in Sun's Java VM. However, if i put tomcat into an infinite loop it seems to go only to just above 50% CPU for the whole system. -Original Message- From: Tim Funk [mailto:[EMAIL PROTECTED] Sent: 17 September 2003 12:49 To: Tomcat Users List Subject: Re: Tomcat on Dual CPU Server The JVM is spec'd to be able to run on multiple processors transparently and an Java application. (Ignoring natvie code issues) Whether the *implementation* of a JVM takes advantage of a multi-cpu system is a job of the JVM vendor. -Tim Stuart Stephen wrote: Hi, I've installed tomcat on a dual CPU redhat linux 9.0 machine and have noticed that it only uses 1 cpu. How can I make it use both? Is this a linux thing or a tomcat thing? - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] This e-mail, including any attachments, is a confidential business communication, and may contain information that is confidential, proprietary and/or privileged. This e-mail is intended only for the individual(s) to whom it is addressed, and may not be saved, copied, printed, disclosed or used by anyone else. If you are not the(an) intended recipient, please immediately delete this e-mail from your computer system and notify the sender. Thank you. - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
