Retry interval. which specifies the length of time to wait before trying
to connect to a server that has been marked temporarily unavailable. The
plug-in marks a server temporarily unavailable if the connection to the server
fails. Although a default value is 60 seconds, you might have to lower this
value in order to increase throughput under heavy load conditions. Lowering
the RetryInterval might help when the IBM HTTP Server is configured to have
fewer than 10 threads per process.
How can lowering the RetryInterval
affect throughput? If the plug-in attempts to connect to a particular application
server while the application server threads are busy handling other connections,
which happens under heavy load conditions, the connection might time out,
causing the plug-in to mark the server temporarily unavailable. If the same
plug-in process has other connections open to the same server and a response
is received on one of these connections, the server is marked again. If there
are only a few threads per IBM HTTP Server process, there might not be an
established connection to this application server . When this situation occurs,
the plug-in must wait for the entire retry interval.
Note: Although
lowering the RetryInterval can improve performance, if all the application
servers are running, a low value can have an adverse affect when one of the
application servers is down. In this case, each IBM HTTP Server process attempts
to connect and fail more frequently, resulting in increased latency and decreased
overall throughput.