Apache versions – Oracle Audio Technologies A86828-01 User Manual
Oracle HTTP Server powered by Apache Performance Guide
The problem is that when a connection becomes idle, and the server closes it
because the keep alive time limit has expired, the client host may not perform the
TCP protocol steps required to complete the closure of the connection. The host,
having sent the close request, is left with the connection in the FIN_WAIT_2 state
taking up memory until it gets the appropriate packets back from the client, or until
an internal flush occurs. If a connection is left in the FIN_WAIT_2 state, the httpd
process with which the connection is associated is freed to service other requests as
indicated, so this problem won’t tie up web server processes.
The difference between Apache versions 1.3.9 and 1.3.12 was primarily corrected
bugs. With static page and servlet performance measurements, there was no
performance difference measured between the versions.