Re: keepalive configuration

On Tue, Dec 09, 2003 at 02:12:11PM -0500, Zachary Giardalas wrote:
> Kragen Sitaker wrote:
> >On Tue, Dec 09, 2003 at 10:13:16AM -0500, Zachary Giardalas wrote:
> >>I've played with some of the demo apps on the mod-pubsub.org site and on 
> >>a test server that we've setup here.  When sniffing the connection, I 
> >>find that from the mod-pubsub site javascript keepalive messages are 
> >>sent once every 15 - 30 seconds, whereas the same app from our test 
> >>server sends them about once per second.

So you're running the Perl server module, while mod-pubsub.org is using the
Python server, which doesn't use Apache.

> No, there are no single byte keepalives.  The keepalives I've seen with
> my 1.3 installation are http continuations consisting of 8 bytes
> containing spaces and CRLFS, which are sent once per second or more.

Probably (assuming HTTP/1.1) you're using chunked encoding, which
means that even a single byte must be transmitted with a count preceding
it.  Something like this:

0001<CR><LF>
 <CR><LF>

Maybe that's what you're seeing?

> The mod_pubsub.org based apps contain at least 127 bytes of javascript
> (many are far more wasteful), but only send every 15 to 30 seconds.

I think the Python server defaults to sending a keepalive space every
60 seconds, and the Perl server defaults to sending them every half
second, but I'm not sure.


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