-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Tony,
On 12/9/2010 5:15 PM, Tony Anecito wrote: > I have done alot of work with another servlet container and your > consultant is correct. More instances do make a difference. Mainly > because certain resources like ports/threads and memory management > for the heap it makes sense. Ports shouldn't be an issue, though dispatching requests to threads could be depending on the connector in use. Can you give us an example of the resource contention you saw drop dramatically with a simple JVM split? I'm not sold on the heap: if you have two GC processes running in parallel (that is, in separate JVMs) I'm not convinced that you are saving yourself any CPU time. Sure, the CPU time required in a single JVM might drop in half, but then you double the number of JVMs so you're back where you started. What kind of GC were you using? > But you still need to test to determine what works best. Thank you for saying that, regardless of any other comments ;) > I agree about the context funkyness. Been there done that. I went > from 2 cpu to 6 cpu (AMD not Intel) and then tuned my html page size > and that made a huge difference. My own IT group was floored by the > performance. My web service response times are down in the 1.5msec > range using Tomcat and APR. I used to have around 1msec but I think > the CPU management and added cpu count caused that to happen. Please clarify: did you simply get a bigger box and experience leaps and bounds of performance increases, or are you saying that you got a bigger box /and/ split into multiple JVMs? I just want to be clear... in your first paragraph above, you said that John's consultant was right and were very vague about why things might go faster. In the second paragraph, you talk about upgrading memory and tweaking application settings and /then/ the IT folks were happy with the performance characteristics you observed. Were these two separate incidents, or was everything together? It's just not that surprising to me that tripling the number of CPUs would improve your webapp's performance -- though most applications are /not/ CPU bound in my experience. > Remember to turn off services you do not need and use NUMA and any > other settings that might help Using NUMA-aware GC would probably help. > like operand compression for the 64-bit jvm if you use it. Er, do you mean "compressed OOPs"? I think that will actually slow things down, since it requires an extra ADD (more likely SHIFT) operation to decode each OOP when referencing the associated object. - -chris -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAk0BoDEACgkQ9CaO5/Lv0PCC7ACfdOoID8pktL/L0zYboY9MEvNo l8cAn35NZTxMIqRI56LXNAhxStvwx5w9 =6Y5h -----END PGP SIGNATURE----- --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
