-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 André,
On 10/26/2009 11:52 AM, André Warnier wrote: > Assuming there is a single (and default) Host, like this : > <Host name="locahost" ...> > <Alias name="somealias.company.com"> > </Host> > > and multiple requests comes in with a header > Host: somealias.company.com > > then indeed the fact of having this Alias, would be faster than not > having it, wouldn't it ? In the case of a single default <Host> with no aliases, you'll get: 1 string compare in findIgnoreCase (compares requested hostname) 1 string compare in find (compares default hostname) 1 string compare in internalMap (compares default hostname to itself) In the case of a single <Host> with the <Alias>, you'll get: Hmm. Re-reading the code for findIgnoreCase, line 1037 is making me frown a bit. It seems that the requested hostname is /always/ compared to the first <Host> element. If the requested hostname is "inferior" to the name of the first <Host>, then -1 is returned and the default host is used. > And in such a case, Chuck's comment that > "Note that if you have only one <Host>, <Alias> elements are completely > superfluous." > would be, in fact, incorrect. Ha ! I'm still undecided until I see an explanation of the line of code above. > We need one of these nice graphs showing the respective gains here.. > Don't you feel tempted ? No, but I'll happily look at your graph once completed ;) > About your optimisation suggestions, I see another possible one : > If this is a keep-alive connection, then the same Tomcat thread will > handle subsequent browser requests over that same connection. There's a check for an existing previously-chosen host at the top of internalMap. I suspect that this is already handled once the first of several keep-alive requests is handled. > As far as I know, there isn't really a case where a browser will issue > multiple requests over the same connection, if not addressed to the same > Host. It would certainly break a lot of clients and servers if the above weren't true: there would be no guarantee that all the "Host" headers would resolve to the same IP address, so the connection might be invalid. On the other hand, issuing a different Host in the middle of a series of keep-alive requests might actually confuse certain components of the server if they all expect the Host to remain constant. > So the thread could also cache a pointer to the Host entry > obtained in the first request of the connection, and re-use it without > lookup for subsequent requests over the same connection. Yeah, I think this is already being done. See above. - -chris -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAkrlzaIACgkQ9CaO5/Lv0PA2NwCfRJrZoLE59xxW+UYDOUrM3jBm Lc0AnRq303TSx3+Aqro1HrUUD4xjBZzA =jfna -----END PGP SIGNATURE----- --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
