I wrote a couple of programs using NETIPC intrinsics to transfer data between
data bases and MPE files in different accounts and/or machines.  These
programs
run about 60 to 70 times per day, and after 3 years of continuous use they
began
to get a Socket Error 50, Invalid Data Length, once in a while, maybe a
couple of
times a month.  The error ALWAYS occurs on the first of a pair of calls to
IPRECV,
the one which reads the next two bytes to get the length of the data packet
to
follow.  I put in a single retry whenever this error is encountered, but so
far that
has not helped: it just gets the same error again.  We have not been able to
identify any kind of hardware or software change that seems to coincide with
the appearance of this error.
 
The programs are in Fortran/77, and have run under MPE/XL 1.0, 2.1, and 4.0.
The Socket Error 50 did not appear until 4.0.
 
Error checking in the programs prevents any data loss; the next time the
programs
run they re-transmit the same data and then the transfer succeeds.  Still, it
is
annoying to keep getting an error I can't explain.  Any ideas on what I might
check would be appreciated.
 
Cecile Chi