This issue came up in testing sds-keyval. The scenario is as follows: A client issues one "open" RPC, then X "put" RPCs, then on "shutdown" RPC. If X is 31 or greater, the "shutdown" RPC will cause the following error on the client side:

# HG -- Warning -- /home/mdorier/spack/var/spack/stage/mercury-master-nreeb4qqqsnhpfwmrl22o7shh7vnv2es/mercury/src/mercury_core_header.c:293
 # hg_core_header_response_verify(): Response return code: HG_INVALID_PARAM

And in the server:

# HG -- Error -- /home/mdorier/spack/var/spack/stage/mercury-master-nreeb4qqqsnhpfwmrl22o7shh7vnv2es/mercury/src/mercury_core.c:2229
 # hg_core_process(): Error while executing RPC callback

To try the code in sds-keyval, call the server as follows:

bin/sdskv-server-daemon -f addr.txt na+sm mydb:bwt

and the client as follows:

test/sdskv-put-test `cat addr.txt` 1 mydb 40