What does connection keep alive means?

HTTP keep-alive, a.k.a., HTTP persistent connection, is an instruction that allows a single TCP connection to remain open for multiple HTTP requests/responses. By default, HTTP connections close after each request. Keep-alive also reduces both CPU and memory usage on your server.

How does connection keep alive work?

Connection: Keep-Alive When the client sends another request, it reuses the same connection. The connection will continue to be reused until either the client or the server decides that the conversation is over, and one of them drops the connection.

How do I make my connection keep alive?

How to enable keep-alive connections

Edit or create an . htaccess file in your site’s document root directory.
Copy the following lines and paste them into the .htaccess file: Header set Connection keep-alive
Save your changes to the . htaccess file.

What is the purpose of keep alive message?

A keepalive (KA) is a message sent by one device to another to check that the link between the two is operating, or to prevent the link from being broken.

How long does a TCP connection last?

TCP connections will generally last about two hours without any traffic. Either end can send keep-alive packets, which are, I think, just an ACK on the last received packet. This can usually be set per socket or by default on every TCP connection. An application level keep-alive is also possible.

What is the benefit of using a persistent connection?

Persistent connections can also be used with APIs to enable servers to push data to clients. Other benefits of persistent connections include reduced network congestion, latency and CPU and memory usage due to the lower number of connections; errors can also be reported without closing the connection.

How long you can keep a TCP connection alive?

There is no limit in the TCP connection itself. Client and server could in theory stay connected for years without exchanging any data and without any packet flow. Problems are usually caused by middleboxes like NAT router or firewalls which keep a state and expire the state after some inactivity.

How do I check my keep alive connection?

All modern browsers use persistent connections as long as the server has Keep-Alive enabled. In order to check if your pages are delivered with a Keep-Alive header, you can use the HTTP Header Checker tool. This will display the Connection: Keep-Alive field if the HTTP Keep-Alive header is enabled.

Where do you put Keep-Alive?

How to Enable Keep Alive in Apache

Open Apache Config File. Open terminal and run the following command to open Apache server configuration file.
Enable Keep Alive in Apache. Add the following lines as per your requirement.
Restart Apache Server.
How to Know If Keep-Alive is Enabled.

What is long lived TCP connection?

By long-lived connection I mean TCP connections that are opened once and then used for tens of minutes, hours or even days. Basically any connection that you don’t open, use for a few seconds and then tear down.

What does keep-alive mean on Wireshark?

A TCP Keep-Alive is sent with a Seq No one less than the sequence number the receiver is expecting. Because the receiver has already ACKd the Seq No of the Keep-Alive (because that Seq No was in the range of an earlier segment), it just ACKs it again and discards the segment (packet).

What is keep alive timeout?

The keep alive timeout on the Message Processor allows a single TCP connection to send and receive multiple HTTP requests/responses from/to the backend server, instead of opening a new connection for every request/response pair.

What are the benefits of connection keep alive?

Enabling the keep-alive header allows you to serve all web page resources over a single connection. Keep-alive also reduces both CPU and memory usage on your server. In the event that keep-alive is not enabled on your server, it can be turned on by adding the following code to your .htaccess file:

Is it possible to keep HTTP connection keep-alive?

HTTP connection can be kept alive with a parameter setting, Keep-Alive: timeout=15, max=100 Is it possible to keep the connection alive indefinitely to a server endpoint? If so, how? Stack Overflow About

What does the keep alive instruction in http mean?

What does keep alive mean for a TCP connection?

Establishing a TCP connection first requires a three-way handshake – a mutual exchange of SYN and ACK packets between a client and server before data can be transmitted. Using the keep-alive header means not having to constantly perform this process.