Yes, same webapp load - i.e. they're both handling the same number of transactions per second.
I guess the only advantage of multiple JVM's is reliability - if one instance goes down the other can still handle load on that machine. Also; I guess someone thought originally that 2 instances doing less work would be easier for the VM to handle and therefore more performant than one instance doing it all - clearly not! ( I didnt set this architecture up - If it's best practice to use one VM on each app server then fair enough - i'd like to read up why tho! ) Thanks! Dan --------- Original Message -------- From: Tomcat Users List <users@tomcat.apache.org> To: Tomcat Users List <users@tomcat.apache.org> Subject: Re: CPU usage quirk with multiple tomcat instances Date: 04/05/08 12:49 > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > Da, > > Lists wrote: > |> My guess (and that's all it is) is that you have eliminated much of the > |> context-switching overhead that two instances would have compared to one. > | > | Ah I see. I guess i can look at that with mpstat and look at things like > | thread migrations etc. Important because if we install more CPU's i guess > | that may mitigate the context switching overhead. Or maybe we can gain > | performance by tying zones to one or two cpu's. > > Is there any advantage to running multiple JVMs on a single machine? Why > not just give your single JVM a big chunk of memory and let it do its thing? > > | Opteron 254 vs 252. So 0.2ghz less but afaik no other difference. Not > | enough of a difference to account for the additional cpu. so this box > uses > | 80% cpu vs 30% on the other one for the same load. > > Do you mean "same webapp load"? Obviously, that addition load is coming > from /somewhere/. What about other services running on the same machine? > > - -chris > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.4.9 (MingW32) > Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org > > iEYEARECAAYFAkgdrqkACgkQ9CaO5/Lv0PCgqACfRxKediPbJyxkYpcBA0z1Qslt > 5M8An1t6VYvyOh3+tMThcXqIZcHQFGVc > =y2AR > -----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] > > > ________________________________________________ Message sent using UebiMiau 2.7.10 --------------------------------------------------------------------- To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
