A socket server coded in rexx, the server recieve data from client socket, when a whole packet arrived, the server invoke coresponding packet handler, after the packet handler proccessed the packet, the server send the result to client socket.

socksvr.rexx: socket server coded in rexx, the main logic of the server.

strsvr.jcl: jcl to run the server as a batch job in mainframe.

config.ini: configuration file to set server parameters and configure packet handler

RXPDSMGT.rexx: packet handler to read a pds member(or sequential dataset) and return the content to client

RXSYSCMD.rexx: packet handler to execute a command and return the result to client

pycli.py: a sample python client to send packet to server and print the result

1. use ftp to transfer config.ini, strsvr.jcl, socksvr.rexx, RXPDSMGT.rexx and RXSYSCMD.rexx to a pds in mainframe.
2. submit strsvr.jcl as a batch job.

Done! the server is ready for use!

8 bytes packet type + 10 bytes content length + content length bytes of content

packet type is used to decide which packet handler to invoke to process the packet, and the content length is used to decide whether the whole packet is arrived.

8 bytes message id + 10 bytes content lenght + content length bytes of content

rule of message id:

• the first 2 bytes of message id is 'RX'

• the next 1 bytes represent module, 'S' means socket server main module, 'H' means packet handler.

• the next 4 bytes represent message number.

• the next 1 bytes represent message type. 'I' means information, 'W' means warning, 'E' means error.

commonly used message id:

• RXH0000I: packet proccessed sucessfully

• RXS0001E: packet handler interface error

• RXS0002E: packet handler not found

New packet handler can be conveniently added to the server, once new packet handler developped, you can configure as shown below:

1. edit configuration file, add a line like this: packet_type=paket_handler /* add a new packet handler */

2. put the new packet handler rexx scripts in the rexx library specified in the jcl

3. restart the server batch job.