KeepAlive
Description |
Enable HTTP Keep-Alive to serve multiple
requests within a single TCP/IP connection |
Synopsis
|
KeepAlive [on | off] |
Context |
Default Server, Virtual Host |
Example
|
KeepAlive on |
The KeepAlive directive enables the HTTP Keep-Alive
facility where a single TCP/IP connection may be reused for
multiple requests. They can significantly speed up overall
performance particularly over longer connections where the TCP/IP
connection setup time is long.
Keep-Alive is supported by AppWeb with both HTTP/1.0 and HTTP/1.1
protocols. With HTTP/1.1, Keep-Alive is the default. With
HTTP/1.0, clients may optionally request Keep-Alive.
Connections can only be reused if the length of the content
returned to the client is know ahead in advance to that a
Content-Length header can be correctly formatted. This means that
very large CGI, ESP or EGI output may cause a TCP/IP connection
to be closed and the effectiveness of Keep-Alive to be
limited.
KeepAliveTimeout
Description |
Set the time period to hold a TCP/IP
connection open for further requests when using
Keep-Alive. |
Synopsis
|
KeepAliveTimeout seconds |
Context |
Default Server, Virtual Host |
Example
|
KeepAliveTimeout 120 |
The KeepAliveTimeout directive defines the time period to
keep connections open waiting for further requests from a given
client. If further requests arrive, the timeout period is
restarted.
Setting the timeout period too high may impact performance on
high-traffic servers because of the large number of open TCP/IP
connections.
MaxKeepAliveRequests
Description |
Define the maximum number of requests for a
connection. |
Synopsis
|
MaxKeepAliveRequests number |
Context |
Default Server, Virtual Host |
Example
|
MaxKeepAliveRequests 50 |
The MaxKeepAliveRequests directive defines the maximum
number of requests that may possibly be services using a single
TCP/IP connect. Limiting the number to a reasonable maximum can
help reduce the impact of some denial of service attacks.
SendBufferSize
Description |
Set the TCP/IP buffer size. |
Synopsis
|
SendBufferSize limit |
Context |
Default Server |
Example
|
SendBufferSize 8192 |
The SendBufferSize directive sets the TCP/IP buffer size.
Increasing the SendBufferSize can improve throughput and lower
CPU usage. You should only need to do this if you have very high
data rates.
The
limit may be set to 0 to use the O/S
default value.
SessionTimeout
Description |
Set an inactivity time period before
disposing of a session data store
|
Synopsis
|
SessionTimeout seconds
|
Context |
Default Server, VirtualHost |
Example
|
SessionTimeout 1800
|
The SessionTimeout directive defines the number of
seconds of inactivity to wait before disposing a session data
store. Embedded Server Pages (ESP) will create session data
stores to store user's state data. If the user abandons their
session, the session will be cleaned up when this timeout
expires. It is good practice for ESP pages to explicitly dispose
of sessions when a user completes a transaction or logs
off.
Timeout
Description |
Set the time period to wait before
cancelling the request |
Synopsis
|
Timeout seconds |
Context |
Default Server, Virtual Host |
Example
|
Timeout 600 |
The Timeout directive defines the number of seconds of
I/O inactivity to wait before cancelling a client request. This
timeout is necessary to cleanup idle connections.
Some web user interfaces with monitoring applets open HTTP
connections and keep them open to stream response data back to
the applet. To prevent AppWeb from closing the connection, you
may need to either increase the timeout value, or you may need to
do some I/O to the applet to ensure it does not get closed.