NOT11 — Suspension of connections

Summary: This issue relates to the ability provided in Notification Service
ProxyPushSuppliers for a consumer to suspend a connection to the channel
(stop the channel pushing events to it) which is unavailable to the
other passive clients of the service - pull suppliers.

The problem arises because, without the ability for a pull supplier to
suspend a connection, its only choices are

(a) to block the return of a pull() call until it is able to
supply an event - resulting in some ORB-dependent timeout on
the call, or a blocked thread in the channel.

(b) to reply to many unnecessary try_pull() calls with a FALSE
result - expecting that the channel will use some sort of
backoff algorithm.

(c) to disconnect from the proxy and obtain a new one when it is
ready to supply events again - causing significant overhead
for both itself and the channel.
I suspect that we only provided one set of suspend/resume operations
because the only circumatance we considered in the design was data
overrun at consumer clients. We ignored the traditional symmetry, and
neglected "under-run" and its less disasterous, but still significant
problems.

No Data Available