RE: [squid-users] Squid 3.x very slow loading on ireport.cnn.com

Already did use Wireshark. Here is some more info:

If you look through the traces you'll notice that at some point Squid sends a TCP [FIN, ACK] right in the middle of a connection for seemingly no reason. (Attempting to close the connection) The server ignores this and sends the rest of the data, which Squid responds to with TCP RST (request to reset) since it now believes the connection to be closed.

From the browser side it seems to be given no notification that the connection was closed (and indeed I can see no reason why it should be closed) so it seems to sit around doing nothing as it may have reached the max connections limit. After about 2 minutes (possibly related to a persistent connection timeout limit in squid) Squid seems to terminate all the connections with FIN,ACKs. The browser then seems to realize its connections are gone and it requests the remaining resources resulting in a bunch of TCP SYNs followed by the rest of the resources.

Why it does this in the middle of connections we still have no clue, however turning off server_persistent_connections seems to make it load fast. However this is probably a bad idea in general...

Max

-----Original Message-----
From: Henrik Nordström [mailto:henrik_at_henriknordstrom.net]
Sent: Sunday, January 23, 2011 7:16 PM
To: Max Feil
Cc: squid-users_at_squid-cache.org
Subject: RE: [squid-users] Squid 3.x very slow loading on ireport.cnn.com

tor 2011-01-20 klockan 02:50 -0500 skrev Max Feil:
> Thanks. I am looking at the squid access.log and the delay is caused by
> a GET which for some reason does not result in a response from the
> server. Either there is no response or Squid is missing the response.
> After a 120 second time-out the page continues loading, but the end
> result may be malformed due to the object which did not load.

I would take a peek at the traffic using wireshark to get some insight
in what is going on there.

REgards
Henrik
Received on Mon Jan 24 2011 - 04:36:10 MST