Large volume of send requests prevents some sendings from succeeding

Question

When I concurrently run 10 scripts with a file event job, which each script sends 100 0.1 MB files, not all sendings will succeed.
Please tell me the cause and a workaround.

Answer

In HULFT Transfer, if any of the following conditions are met and a large number of send requests are made at the same time, the send requests will be held up and some requests will time out when the sending process is not started for a certain period of time.
-Request for sending to a same Transfer service (outbound) associated with a same HULFT Transfer Send
-Request for sending to a same Transfer service (outbound) associated with a same HULFT Transfer Host

HULFT Transfer Service is designed to block send requests with a same key from the start of the former sending to its completion, resulting in sending request retention and timeout when a large number of send requests are made.

There is no workaround for this problem, as the sendings failed due to the timeout specification.
Please note that this event is a performance limitation.