> > As i said we can easily reproduce this with midas/examples/odbxx/odbxx_test.cpp  (with cm_connect_experiment changed to "localhost")
> > [test,ERROR] [system.cxx:5104:recv_tcp2,ERROR] unexpected connection closure
> > [test,ERROR] [system.cxx:5158:ss_recv_net_command,ERROR] error receiving network command header, see messages
> > [test,ERROR] [midas.cxx:13900:rpc_call,ERROR] routine "db_copy_xml": error, ss_recv_net_command() status 411, program abort
> 
> ok, cool. looks like we crashed the mserver. either run mserver attached to gdb or enable mserver core dump, we need it's stack trace,
> the correct stack trace should be rooted in the handler for db_copy_xml.
> 
> but most likely odbxx is asking for more data than can be returned through the MIDAS RPC.
> 
> what is the ODB key passed to db_copy_xml() and how much data is in ODB at that key? (odbedit "du", right?).
> 
> K.O.

Ok. Maybe i have to make this more clear. ANY odbxx access of a remote odb reproduces this error for us on multiple machines. 
It does not matter how much data odbxx is asking for.

Something as simple as this reproduces the error, asking for a single integer:

int main() {
   cm_connect_experiment("localhost", "Mu3e", "test", NULL);
   midas::odb o = {
      {"Int32 Key", 42}
   };
   o.connect("/Test/Settings");
   cm_disconnect_experiment();
   return 1;
}

at the same time this runs fine:

int main() {
   cm_connect_experiment(NULL, NULL, "test", NULL);
   midas::odb o = {
      {"Int32 Key", 42}
   };
   o.connect("/Test/Settings");
   cm_disconnect_experiment();
   return 1;
}

in both cases mserver does not crash. I do not have a stack trace. There is also no error produced by mserver.

Last year we did not have these problems with the same midas frontends (For example in midas commit 9d2ef471 the code from above runs 
fine). I am trying to pinpoint the exact commit where this stopped working now.