The concept of http persistent and non-persistent

[cjrchoi11]

pls somebody explain me the concept of "keepalive type http".

when and where configure the persistent and non-persistent? not clear from the doc that HTTP-head, HTTP-get, classA and classB.

Thanks in advance.

[Gilles Dufour]

Persistent will use HTTP version 1.1 while non-persistent will use version 1.0.

Use non-persistent only if your server does not support http version 1.1.

HTTP method HEAD or GET is selected with the command 'keepalive method'.

A head does not require the server to send us the content of the requested file, but simply an acknowledgement that the file is available.

The GET will request the complete file from the server and the CSS will verify that the content did not change compare to first GET request.

Again, I would recommend the default - head, unless you believe somebody could corrupt the content of your website.

Regards,

Gilles.

[cjrchoi11]

Thanks a lot. some more basic questions.

Q1) what's difference between persistent and non-persistent in the behavior perspective? ex, persistent trying keep continue keepalive into the http server?

Q2) there are table explained the ClassA and B based on the keepalive type. why "http-head non-persistent" is classA versus classB for "http-persistent"? I want to understand relate to the operational behavior.

Regards,

[Gilles Dufour]

I'm glad you asked the question. I had to verify the behavior to be sure of my answer.

When using persistent connections, the CSS only open 1 TCP connection, and it keeps it open for all keepalive HTTP requests.

If using non-persistent, the CSS will open a new connection for every keepalive and close it after receiving the server response.

Regards,

Gilles.

[cjrchoi11]

Thanks Gilles. getting clear the "persistent" concept. I have an another basic question regards the load balancing.

A.balance srcip(same src IP to the same service)

B.balance destip(same dest IP to the same service)

C.balance roundrobin(evenly distribute)

Q1) looks A is stick to specific service and analogue to "advanced-balance sticky-srcip". what's difference?

Q2) in C, what's decision mechanism(ex, source IP) to distribute evenly?

Regards,