Request duplication across batches following epoch transition

[harrymknight]

Following epoch transition requests are sometimes duplicated across batches e.g

First epoch

&{Preprepare:seq_no:189 epoch:1 batch:{client_id:1 req_no:588 digest:"I\xffu\x0b\xca\xc0A\xc4\x06\x9a\x00*\xce#N_\x97\x9bt\x03\xa7\x83\tՁ@\xab\x85\xca\xf02\xd0"} batch:{client_id:1 req_no:592 digest:"P?\x82\x1e\x95\x16\x12ϜX\x85\xaf\xb4\xfbղy\x86\xb6\xa8\xb5\x05n\x85w\xd3ު\xee\x08\xeaf"} batch:{client_id:1 req_no:596 digest:";\xb3\xedR\xcf\x1eM\xdf\xef\xac\xf4X\xa46\xe9\xe58\xda̘X%\x81\x01\x05!\xb4\xbf\xbe`\xbe\x9a"} batch:{client_id:1 req_no:600 digest:"sG\xb7\xd2k\xe7!L\xfaA\x83J\x16\xef<\xed\xe2\xa7\xf4\x98ҫ\xf7%T\xc34\x07\xcb-"} batch:{client_id:1 req_no:604 digest:"\x98j%\xa2lE\xd1K\xfa\x00E\x86\x1f~=\x8e\x81\x12й\xe2\xf3F\xea=\xd9\x1b\x93\xacp\x8a\xf0"}}
&{Prepare:seq_no:189 epoch:1 digest:")a\x10\x04\xacIbܟ0\xc8\xfc\xd4\x0eP\xfe\xf6\x0c_\xa0Vγ\x06G\xaf\xc9#c\n}a"}
&{Commit:seq_no:189 epoch:1 digest:")a\x10\x04\xacIbܟ0\xc8\xfc\xd4\x0eP\xfe\xf6\x0c_\xa0Vγ\x06G\xaf\xc9#c\n}a"}

Second epoch

&{Preprepare:seq_no:201 epoch:2 batch:{client_id:1 req_no:588 digest:"I\xffu\x0b\xca\xc0A\xc4\x06\x9a\x00*\xce#N_\x97\x9bt\x03\xa7\x83\tՁ@\xab\x85\xca\xf02\xd0"} batch:{client_id:1 req_no:592 digest:"P?\x82\x1e\x95\x16\x12ϜX\x85\xaf\xb4\xfbղy\x86\xb6\xa8\xb5\x05n\x85w\xd3ު\xee\x08\xeaf"} batch:{client_id:1 req_no:596 digest:";\xb3\xedR\xcf\x1eM\xdf\xef\xac\xf4X\xa46\xe9\xe58\xda̘X%\x81\x01\x05!\xb4\xbf\xbe`\xbe\x9a"} batch:{client_id:1 req_no:600 digest:"sG\xb7\xd2k\xe7!L\xfaA\x83J\x16\xef<\xed\xe2\xa7\xf4\x98ҫ\xf7%T\xc34\x07\xcb-"} batch:{client_id:1 req_no:604 digest:"\x98j%\xa2lE\xd1K\xfa\x00E\x86\x1f~=\x8e\x81\x12й\xe2\xf3F\xea=\xd9\x1b\x93\xacp\x8a\xf0"} batch:{client_id:1 req_no:608 digest:"\xa2\xeb׼\x86#řf\x88\xa6\x1d\x1551BK\xb1\x11V.-sݿ\xaal\xabԬ\x89\x93"} batch:{client_id:1 req_no:612 digest:"id<\xe9\xc8\xcb\xcb\xd3P\xdbӫ\xdb\x10\xea,\x16Q\x82zJ4\xaa|\xb0݉\x95\xdc\xd1\xcei"} batch:{client_id:1 req_no:616 digest:"\xa9\x0b\xfc\x1fn\xfeE\x08A\xd8.\xc0\x18TV\xa0\x03:[& \xc1"\x10\xd4g;M\xb4\xf0\xdc$"} batch:{client_id:1 req_no:620 digest:"\x81\x8c\x9c\x10S9\xf71\xad\xc3\x0c\xb1n\xe6BUi\x18\xf3a\xb8;\x06!\x90t\xbb\x17\x80\x89Z\xaa"} batch:{client_id:1 req_no:624 digest:"6JUt\x91\x7fD\xe6\xebH\xd5\x08ako\xa3#\x03\xe8\xcbe#C;E\xfc\xc0\xbc\xcb\x07V\x05"}}

Note that in the first epoch these requests are committed so they shouldn't be present in the following epoch.

[matejpavlovic]

This issue is legitimate, but concerns legacy code (on the legacy branch) and should not be expected to be fixed.