-\subsubsection faq_trouble_gras_transport GRAS spits networking error messages
-
-Gras, on real platforms, naturally use regular sockets to communicate. They
-are deeply hidden in the gras abstraction, but when things go wrong, you may
-get some weird error messages. Here are some example, with the probable
-reason:
-
- - <b>Transport endpoint is not connected</b>: several processes try to open
- a server socket on the same port number of the same machine. This is
- naturally bad and each process should pick its own port number for this.\n
- Maybe, you just have some processes remaining from a previous experiment
- on your machine.\n
- Killing them may help, but again if you kill -KILL them, you'll have to
- wait for a while: they didn't close there sockets properly and the system
- needs a while to notice that this port is free again.
-
- - <b>Socket closed by remote side</b>: if the remote process is not
- supposed to close the socket at this point, it may be dead.
-
- - <b>Connection reset by peer</b>: I found this on Internet about this
- error. I think it's what's happening here, too:\n
- <i>This basically means that a network error occurred while the client was
- receiving data from the server. But what is really happening is that the
- server actually accepts the connection, processes the request, and sends
- a reply to the client. However, when the server closes the socket, the
- client believes that the connection has been terminated abnormally
- because the socket implementation sends a TCP reset segment telling the
- client to throw away the data and report an error.\n
- Sometimes, this problem is caused by not properly closing the
- input/output streams and the socket connection. Make sure you close the
- input/output streams and socket connection properly. If everything is
- closed properly, however, and the problem persists, you can work around
- it by adding a one-second sleep before closing the streams and the
- socket. This technique, however, is not reliable and may not work on all
- systems.</i>\n
- Since GRAS sockets are closed properly (repeat after me: there is no bug
- in GRAS), it is either that you are closing your sockets on server side
- before the client get a chance to read them (use gras_os_sleep() to delay
- the server), or the server died awfully before the client got the data.
-
