Previously, the UDP inbound adapter was incorrectly using
the default task scheduler (taskScheduler) to run its main
receive activity. Once a packet is read, it is handed off
to another thread for message processing, using a configured
(or default) task executor.
We should not hold on to a scheduler thread permanently; the
default scheduler has only 10 threads and one user's app
stopped working when using 10 inbound adapters.
The work around was to define an explicit 'taskScheduler'
bean with more threads.
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