What is `request flow control ?
AAn iAS engine will attempt to allocate new threads to incoming requests (up to a specified number), and queue any requests that cannot be handled immediately by an existing thread. Queuing is only used when the maximum number of threads is exceeded. The administrator can enable `request flow control’ to limit the number of requests that are queued. When the maximum queue size is reached (`high-water mark’) no further requests are accepted. The engine remains in this state until it has cleared enough requests for the queue to reach the `low-water mark’.If flow control is disabled, there is no restriction on the size of an engine’s request queue (apart from system resources, of course). Enabling flow control is usually only helpful if there are other servers available to accept the requests that would otherwise not be handled. By default, flow control is enabled, but the high and low water marks are both set to zero, which has the same effect as disabling it.
