So, the very first time I ran your example it worked flawlessly:
Slave7328 reporting for duty!
Slave7328 unregistering duty!
Connection closed!
Connection established!
Slave4532 reporting for duty!
Connection established!
Slave444 reporting for duty!
Connection established!
Connection established!
Connection established!
Connection established!
Slave7956 reporting for duty!
Connection established!
Slave1344 reporting for duty!
Connection established!
Connection established!
Connection established!
Slave7208 reporting for duty!
Connection established!
Slave8056 reporting for duty!
Slave4592 reporting for duty!
Slave8072 reporting for duty!
Slave1744 reporting for duty!
Slave6648 reporting for duty!
Slave4328 reporting for duty!
Connection established!
Connection established!
Slave6908 reporting for duty!
Slave8176 reporting for duty!
Connection established!
Connection established!
Connection established!
Connection established!
Connection established!
Connection established!
Slave7556 reporting for duty!
Slave7188 reporting for duty!
Slave7104 reporting for duty!
Connection established!
Slave8004 reporting for duty!
Slave7624 reporting for duty!
Slave7692 reporting for duty!
Connection established!
Connection established!
Connection established!
Connection established!
Slave5000 reporting for duty!
Slave4532 unregistering duty!
Connection established!
Connection established!
Slave7468 reporting for duty!
Slave8424 reporting for duty!
Slave8352 reporting for duty!
Slave3640 reporting for duty!
Connection established!
Slave444 unregistering duty!
Slave8680 reporting for duty!
Slave7056 reporting for duty!
Slave2320 reporting for duty!
Connection established!
Connection established!
Connection established!
Connection established!
Connection established!
Connection established!
Slave7956 unregistering duty!
Slave8640 reporting for duty!
Slave8240 reporting for duty!
Slave1344 unregistering duty!
Connection established!
Connection established!
Slave7208 unregistering duty!
Connection established!
Slave8056 unregistering duty!
Connection established!
Connection established!
Slave4592 unregistering duty!
Slave8628 reporting for duty!
Slave8072 unregistering duty!
Slave8820 reporting for duty!
Slave1744 unregistering duty!
Slave7272 reporting for duty!
Slave8884 reporting for duty!
Connection established!
Slave6648 unregistering duty!
Slave4328 unregistering duty!
Slave8804 reporting for duty!
Slave8256 reporting for duty!
Slave8984 reporting for duty!
Slave8496 reporting for duty!
Slave7716 reporting for duty!
Slave9184 reporting for duty!
Connection established!
Connection established!
Connection established!
Slave8176 unregistering duty!
Slave6908 unregistering duty!
Slave9396 reporting for duty!
Slave9500 reporting for duty!
Connection established!
Connection established!
Slave9532 reporting for duty!
Connection established!
Slave9556 reporting for duty!
Slave9604 reporting for duty!
Connection established!
Connection established!
Slave9732 reporting for duty!
Slave9796 reporting for duty!
Connection established!
Slave10048 reporting for duty!
Connection established!
Connection established!
Connection established!
Slave8220 reporting for duty!
Connection established!
Slave10312 reporting for duty!
Slave7188 unregistering duty!
Slave7556 unregistering duty!
Slave7104 unregistering duty!
Slave10364 reporting for duty!
Slave8004 unregistering duty!
Slave7624 unregistering duty!
Slave10400 reporting for duty!
Connection established!
Slave7692 unregistering duty!
Slave10500 reporting for duty!
Connection established!
Slave5000 unregistering duty!
Connection closed!
Connection established!
Slave10528 reporting for duty!
Slave7468 unregistering duty!
Slave8424 unregistering duty!
Connection established!
Slave8352 unregistering duty!
Slave3640 unregistering duty!
Connection closed!
Slave10660 reporting for duty!
Slave7056 unregistering duty!
Slave8680 unregistering duty!
Slave10724 reporting for duty!
Connection established!
Slave10772 reporting for duty!
Connection established!
Slave2320 unregistering duty!
Connection established!
Slave10928 reporting for duty!
Connection established!
Slave11052 reporting for duty!
Slave11096 reporting for duty!
Connection established!
Slave11176 reporting for duty!
Connection established!
Connection closed!
Slave8640 unregistering duty!
Connection established!
Connection closed!
Slave8240 unregistering duty!
Connection closed!
Connection closed!
Slave10376 reporting for duty!
Connection closed!
Slave10820 reporting for duty!
Connection established!
Connection closed!
Connection closed!
Slave8820 unregistering duty!
Slave8628 unregistering duty!
Slave8884 unregistering duty!
Slave9408 reporting for duty!
Connection closed!
Connection established!
Slave7272 unregistering duty!
Connection closed!
Connection established!
Slave8804 unregistering duty!
Slave8256 unregistering duty!
Slave8984 unregistering duty!
Slave8496 unregistering duty!
Slave7716 unregistering duty!
Slave9928 reporting for duty!
Slave11460 reporting for duty!
Slave9184 unregistering duty!
Slave11632 reporting for duty!
Connection established!
Connection established!
Connection established!
Connection established!
Slave11732 reporting for duty!
Slave11900 reporting for duty!
Connection closed!
Connection established!
Connection closed!
Slave12200 reporting for duty!
Slave12028 reporting for duty!
Slave9396 unregistering duty!
Slave9500 unregistering duty!
Connection established!
Connection established!
Slave12268 reporting for duty!
Connection established!
Slave9532 unregistering duty!
Slave12312 reporting for duty!
Connection established!
Slave10316 reporting for duty!
Slave12412 reporting for duty!
Slave9556 unregistering duty!
Connection established!
Slave9604 unregistering duty!
Connection established!
Slave12532 reporting for duty!
Connection established!
Slave12672 reporting for duty!
Connection established!
Slave9732 unregistering duty!
Slave12972 reporting for duty!
Connection established!
Slave9796 unregistering duty!
Slave13100 reporting for duty!
Connection established!
Slave10048 unregistering duty!
Slave13184 reporting for duty!
Connection established!
Connection established!
Slave13268 reporting for duty!
Slave11492 reporting for duty!
Connection established!
Slave8220 unregistering duty!
Slave4776 reporting for duty!
Connection established!
Slave13424 reporting for duty!
Slave10312 unregistering duty!
Connection closed!
Connection closed!
Connection closed!
Slave10364 unregistering duty!
Connection closed!
Slave13560 reporting for duty!
Connection closed!
Connection established!
Slave10400 unregistering duty!
Slave13644 reporting for duty!
Connection established!
Connection closed!
Connection established!
Slave10500 unregistering duty!
Connection established!
Slave13756 reporting for duty!
Connection closed!
Connection established!
Slave13860 reporting for duty!
Connection established!
Slave13972 reporting for duty!
Slave10528 unregistering duty!
Connection closed!
Connection established!
Slave14080 reporting for duty!
Connection closed!
Connection closed!
Connection established!
Connection established!
Connection closed!
Slave14208 reporting for duty!
Connection closed!
Connection closed!
Slave10660 unregistering duty!
Slave12704 reporting for duty!
Slave13060 reporting for duty!
Connection established!
Slave14384 reporting for duty!
Slave14496 reporting for duty!
Slave10724 unregistering duty!
Connection established!
Connection established!
Connection established!
Slave10772 unregistering duty!
Connection established!
Slave14620 reporting for duty!
Connection established!
Slave14752 reporting for duty!
Connection closed!
Slave15008 reporting for duty!
Slave14884 reporting for duty!
Slave15144 reporting for duty!
Slave15272 reporting for duty!
Slave10928 unregistering duty!
Slave11052 unregistering duty!
Slave11096 unregistering duty!
Slave11176 unregistering duty!
Connection closed!
Connection closed!
Slave10376 unregistering duty!
Slave10820 unregistering duty!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Slave9408 unregistering duty!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Slave9928 unregistering duty!
Slave11460 unregistering duty!
Connection closed!
Slave11632 unregistering duty!
Slave11732 unregistering duty!
Slave11900 unregistering duty!
Slave12028 unregistering duty!
Slave12200 unregistering duty!
Connection closed!
Connection closed!
Slave12268 unregistering duty!
Connection closed!
Slave12312 unregistering duty!
Slave10316 unregistering duty!
Slave12412 unregistering duty!
Connection closed!
Connection closed!
Slave12532 unregistering duty!
Slave12672 unregistering duty!
Connection closed!
Slave12972 unregistering duty!
Connection closed!
Slave13100 unregistering duty!
Connection closed!
Slave13184 unregistering duty!
Slave13268 unregistering duty!
Slave11492 unregistering duty!
Connection closed!
Slave4776 unregistering duty!
Slave13424 unregistering duty!
Connection closed!
Connection closed!
Slave13560 unregistering duty!
Connection closed!
Slave13644 unregistering duty!
Connection closed!
Slave13756 unregistering duty!
Slave13860 unregistering duty!
Slave13972 unregistering duty!
Connection closed!
Slave14080 unregistering duty!
Slave14208 unregistering duty!
Connection closed!
Slave12704 unregistering duty!
Slave13060 unregistering duty!
Slave14384 unregistering duty!
Slave14496 unregistering duty!
Connection closed!
Connection closed!
Slave14620 unregistering duty!
Slave14752 unregistering duty!
Slave15008 unregistering duty!
Slave14884 unregistering duty!
Slave15144 unregistering duty!
Slave15272 unregistering duty!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!
Connection closed!Every subsequent run I ended up with the error you described. My suspicion at this point is that this may be an operating system limitation. In one of our own test cases we start 50k connections simultaneously in a very similar way to yours but all within a maximum of two processes.
I will keep investigating as I am interested to know what the root cause of this is. I do however have to ask why you are interested in this particular use case. It is probably a bad system design to require many independent processes to start within such a short space of time.
Regards,
Marc