Hi,thanks for your notes. Still I don't entirely understand what I see. Here's how I tested. I've set up 2 virtualhosts on my ubuntu gutsy notebook (apache 2.2.4, prefork): localhost and localhost-external.
Here's localhost-external:
<VirtualHost 127.0.0.1:80>
ServerAdmin webmaster@localhost
ServerName localhost-external
DocumentRoot /var/www/apache2-default
ErrorLog /var/log/apache2/error.log
LogLevel warn
CustomLog /var/log/apache2/access.log combined
ServerSignature On
ProxyPass /proxied http://localhost/internal min=30 smax=190 max=200 timeout=120 keepalive=On
ProxyPassReverse /proxied http://localhost/internal
</VirtualHost>
and localhost:
<VirtualHost 127.0.0.1:80>
ServerAdmin webmaster@localhost
ServerName localhost
DocumentRoot /var/www/apache2-default
ErrorLog /var/log/apache2/error.log
LogLevel warn
CustomLog /var/log/apache2/access.log combined
ServerSignature On
</VirtualHost>
Now I've put a small php script called headers.php to both
/var/www/apache2-default and /var/www/apache2-default/internal, which
dumps all http request header data.
If I open url http://localhost-external/headers.php then, among others,
there's the Connection: keep-alive header. OK, now I open
http://localhost-external/proxied/headers.php, and connection keep-alive
is still there. So keep-alive is OK for http backends.
But if I change the ProxyPass and ProxyPassReverse lines in localhost-external to use https instead of http (and set up localhost to serve https), then http://localhost-external/proxied/headers.php shows that the Connection header value changed to "close".
This tells me that it's not possible to use persistent connections to https backends in proxy workers, which is strange, as it seemed to be possible in apache 2.0 mod_proxy. Is this correct or I've made a mistake somewhere?
Thanks for any help, Balint On Tue, 8 Jan 2008, Axel-Stephane SMORGRAV wrote:
Hi This is very surprising to me because this is one of the things about 2.2 that I was looking forward to and therefore tested specifically. Roughly speaking httpd 2.2 creates a connection pool for each ProxyPass. Actually it associates a "worker" (not to be mixed-up with MPM worker workers or worker processes) with each ProxyPass destination, and there is a connection pool associated with each worker. Workers and the associated connections persist across client requests. You may therefore use persistent backend connections even if the client connection is not. This works fine in 2.2.4. There was however a bug in 2.2.0 http://issues.apache.org/bugzilla/show_bug.cgi?id=38602. If you use rewrite rules for proxying however, the back-end connections will not be persistent because the default worker will be used, and the default worker has only non-persistent connections associated with it. There is a way to de-activate keep-alive for back-end connections: setting the proxy-nokeepalive environment variable (see the "Protocol Adjustments" section of the mod_proxy manual pages). In 2.0 back-end connections were persistent only of the client connection was so. Back-end connections could not be used to serve requests from different clients. For further reading, refer to the mailing list archive for last September http://mail-archives.apache.org/mod_mbox/httpd-dev/200709.mbox/thread or my Bugzilla report http://issues.apache.org/bugzilla/show_bug.cgi?id=43308 -ascs -----Message d'origine----- De : KOZMAN Bálint [mailto:qzy@xxxxxxxxxxxxx] Envoyé : mardi 8 janvier 2008 16:45 ? : users@xxxxxxxxxxxxxxxx Objet : mod_proxy and keepalive question Hi there, I'm experiencing a different behaviour of apache 2.2's mod_proxy compared to the one in 2.0. From my point of view the main difference is that 2.0 mod_proxy does not send the "Connection" request header to the backend, while 2.2 mod_proxy always sends "Connection: Close" regardles whether the backend connection goes through http or https. The question is if it's possible to use persistent connections from 2.2 mod_proxy to the backend (and thus force mod_proxy to send "keep-alive" in the Connection header)? Any help would highly be appreciated, thanks, Balint --------------------------------------------------------------------- The official User-To-User support forum of the Apache HTTP Server Project. See <URL:http://httpd.apache.org/userslist.html> for more info. To unsubscribe, e-mail: users-unsubscribe@xxxxxxxxxxxxxxxx " from the digest: users-digest-unsubscribe@xxxxxxxxxxxxxxxx For additional commands, e-mail: users-help@xxxxxxxxxxxxxxxx --------------------------------------------------------------------- The official User-To-User support forum of the Apache HTTP Server Project. See <URL:http://httpd.apache.org/userslist.html> for more info. To unsubscribe, e-mail: users-unsubscribe@xxxxxxxxxxxxxxxx " from the digest: users-digest-unsubscribe@xxxxxxxxxxxxxxxx For additional commands, e-mail: users-help@xxxxxxxxxxxxxxxx
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