-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Mark,
On 3/15/2011 6:02 AM, Mark Thomas wrote: > On 15/03/2011 06:06, Jason Pringle wrote: >> Clearly what is there is correct, since it takes some extra effort to embed >> a Host header into the HTTP request if you don't have a DNS entry (messing >> with /etc/hosts would be one way). But that last bit of info for how Tomcat >> actually makes use of the header would be handy in the docs (I know - >> patches welcome :)) > > I took a stab at improving the docs. You can read the results here. > http://ci.apache.org/projects/tomcat/tomcat7/docs/config/host.html > And yes, patches/suggested changes welcome. > >> Is there any measurable performance optimization of using the name of the >> host that is expected to be in the request? I would guess not, even for a >> very high volume site, but haven't looked at the code. > > There is a very, very small gain. I doubt it it measurable. I haven't looked in-deptch at the mapper, but I was thinking that there could be some performance optimizations for certain cases. I'm not sure such optimizations would be measurable but they are fortunately easy to test. For instance, I guess the hostnames are stored in a Map keyed on lowercase hostname, and each request does a lookup in that Map to determine the host that will handle the request. If the result is null, you choose the defaulHost. If, on startup, we used a pluggable host mapper, we would optimize for certain cases: * Only one host, which is the default - no case-normalization or lookup required: the one host is always the right host * Only 2 or 3 (or whatever) hosts - use if/then to test a small number of host names directly instead of hashing, etc. (similar to using commons-collections Flat3Map) * All other cases: use existing strategy There are a couple of potential problems with this: 1. Added code complexity... have to determine how much performance gain (if any) this complexity adds 2. Interferes with dynamic host add/remove code, though that could be handled as well 3. Problems often come in 3s :) - -chris -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAk1/f08ACgkQ9CaO5/Lv0PABcQCffRKyaBwFPpMunEiWga6AHnEL Xb0AoK5saev3ySVzobnnwQHBs9ibcsHZ =6orN -----END PGP SIGNATURE----- --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
