Thank you, Amos, for your very clear answer. On Wed, Jun 22, 2011 at 7:51 PM, Amos Jeffries <squid3@xxxxxxxxxxxxx> wrote: > On 22/06/11 22:54, Le Trung, Kien wrote: >> >> Hi, I trouble about how to reduce the ESTABLISHED statuses of connections. >> It always have approximately 6300 ESTABLISHED connections when server >> at high load time of the day and just reduce below 1000 ESTABLISHED in >> the midnight. >> >> 1 established) >> 1 Foreign >> 5 FIN_WAIT2 >> 6 LISTEN >> 11 CLOSING >> 43 SYN_RECV >> 63 LAST_ACK >> 237 FIN_WAIT1 >> 1331 TIME_WAIT >> 6258 ESTABLISHED >> >> I wonder how to free the connection after data all been tranferred >> between squid server and clients. (I think squid keeps connections as >> much as possible). > > Depends on which Squid you have. 3.1 and later try to use HTTP/1.1 features > to speed up client access times. These require persistent connections. > > ~6300 connections is not bad. Your box can handle far more than that easily. > >> On another web server (same operating system and hardware, etc ...) >> which has the same connections to (because of DNS round-robin) the >> ESTABLISH connections are range from 2000-3000. > > This is not a valid comparison. see: > http://wiki.squid-cache.org/Features/LoadBalance#Bias:_Connection-based > > This same problem affects DNS round-robin and TCP SYN load balancers. Which > are also per-connection. > > > > Generally speaking ESTABLISHED is good. They are either currently in active > use or waiting and will have zero TCP connection setup delay when they are > needed. > > The more recent your Squid version number the more efficiently it handles > persistent connections. Thus the lower number it uses. So if this is > actually a problem for you a newer version is better. > > You can also adjust it by tweaking the idle_timeout directive. Which > determines a maximum amount of time any one connection can be kept waiting. > > You can disable the persistence and all HTTP features which rely on it by > configuring client_persistent_connections and/or > server_persistent_connections OFF. > > Amos > -- > Please be using > Current Stable Squid 2.7.STABLE9 or 3.1.12 > Beta testers wanted for 3.2.0.9 and 3.1.12.3 >
