Anthony J. Biacco: > Here's my problem. When the request is to a servlet (static apache files > and JSPs through mod_jk are fine) in the form of a GET, instead of > sending a Content-Length response header, I get a Transfer-Encoding: > chunked header > I'd like to know: > 1) What are the causes of either Tomcat (or Apache is it?) enabling > chunking on the connection?
Tomcat, probably, since you're talking about a servlet-created response. And it's not chunking the connection but transferring the response body chunked. If at the time the response headers are sent the size of the response body is already known (for example, if it's just the contents of a file), it's easy to send a Content-Length response header. OTOH, how big the output of a servlet will be is generally not known before the servlet has finished. If you want to send a Content-Length header anyway, I see two (well, really only one) alternatives: 1. Cache the complete servlet output and count the bytes - which isn't very practical.[1] 2. Don't send a Content-Length header. Alternative 2. creates another problem: With HTTP/1.0 a client can quite reliably determine when the entire response body is transferred, even if no content-length header is sent: when the server closes the underlying TCP connection. With HTTP/1.1 this isn't the case any more since the TCP connection may be left open to be used to transfer additional requests/responses (keep-alive). To enable the client to determine when the entire response was transmitted, you'll have to transfer it chunked. > 2) How do I get a Content-Length reponse header instead? Do I need to > downgrade the client to HTTP/1.0 or is there another way? What's the point in caching dynamically created responses? > FYI, the reason I'm trying to do this is that I use a CDN, and they > won't cache my data without the presence of a Content-Length response > header, so my servlet data isn't getting cached at the CDN. What's a CDN? [1] Tomcat will, by default, cache some output of servlets. IIRC the default buffer size is 8k. So, if your servlet creates output of no more then 8k, a Content-Length header will be sent. Otherwise chunked encoding will be used. This might be the reason why you see Content-Length headers from your JSPs - their output is probably small enough. -- Regards mks --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
