1. Running EntireX Broker

2. The basic started task which must be available on OS/390 is EntireX Broker. EntireX Broker

3. DIT specifies a unique “DBID” for the EntireX Broker started task. Along with some other critical Broker sizing parameters. EntireX Broker DBID#

4. DIT customers will normally supply us with a Broker ATTRibute file to be added to the Broker started task. The Broker ATTR file uniquely identifies valid Broker transactions via CLASSes, SERVERs and SERVICEs. EntireX Broker DBID# CUST ATTR

5. The EntireX Broker started task will only provide the basic communications vehicle. The customer application is responsible for starting Broker application servers. These Broker application servers are normally started in a Complete region. The application servers are simply Natural programs which have issued a CALL to Broker specifying DBID#, CLASS, SERVICE and SERVER. These application servers will normally stay in Broker RECV mode. EntireX Broker DBID# CUST ATTR Complete APPLICATION SERVERS

6. Broker applications normally communicate with the “outside world”. So the next requirement is Net-work. Net-work “talks” VTAM and TCP/IP. ALL of the DIT Net-work regions are coded with ACCEPTUI=YES. This means that any one with valid TCP/IP stack and Net-work can communicate with the OS/390 Net-work. There is no need to define IP addresses on Net-work. Each Net-work region will have a unique TCP/IP port number. EntireX Broker DBID# CUST ATTR Complete APPLICATION SERVERS Net-work port#

7. The next requirement is a TCP/IP stack. The Interlink TCP/IP stack is what we use at DIT. EntireX Broker DBID# CUST ATTR Complete APPLICATION SERVERS Net-work port# TCP/IP

8. Any access to the DIT TCP/IP stack must come thru either the Raptor or PIX Firewall. A Firewall authorization form must be filled out for access. EntireX Broker DBID# CUST ATTR Complete APPLICATION SERVERS Net-work port# TCP/IPFirewall

9. The next piece to the puzzle is a TCP/IP stack on the client side. Most platforms now come with a TCP/IP stack. EntireX Broker DBID# CUST ATTR Complete APPLICATION SERVERS Net-work port# TCP/IPFirewall Client TCP/IP Stack

10. The next piece to the puzzle is Net-work on the client side. The client Net-work parameters contain the TCP/IP address of the front-end of the Firewall and the TCP/IP port# which it wants to communicate with. The client Net-work is normally auto-started when the client system is booted/started. Most client Net- works also will try to auto-reconnect after some pre-defined time period if the TCP/IP connection has been broken for some reason. EntireX Broker DBID# CUST ATTR Complete APPLICATION SERVERS Net-work port# TCP/IPFirewall Client TCP/IP Stack Client Net-work

11. The last piece to the puzzle is the client application. The code itself can be pretty much any language. With the client Net-work, Software AG supplies a CALLable routine (usually) ADALNK which will facilitate “ADABAS Direct Calls” across the Net-work(s). EntireX Broker DBID# CUST ATTR Complete APPLICATION SERVERS Net-work port# TCP/IPFirewall Client TCP/IP Stack Client Net-work Application Code

12. But wait, not all of the pieces are connected!! Correct. Keep in mind that the application servers are still in RECV mode. They are constantly waiting for “input”. Something on the client will initiate a Broker CALL. Again, this Broker CALL must contain a DBID#, CLASS, SERVER and SERVICE in order to uniquely identify the application servers it wants to “talk” to. EntireX Broker DBID# CUST ATTR Complete APPLICATION SERVERS Net-work port# TCP/IPFirewall Client TCP/IP Stack Client Net-work Client Application Code

13. Normally, the application server programs will want to read or update information from ADABAS. So I have added the an ADABAS region as the last piece to the puzzle. EntireX Broker DBID# CUST ATTR Complete APPLICATION SERVERS Net-work port# TCP/IPFirewall Client TCP/IP Stack Client Net-work Client Application Code ADABAS

14. EntireX V511 also provides the option for Broker applications to “talk” directly to native TCP/IP without having to go thru the Net-work middleware. But how do they do this?? The first piece is specifying a port# on the EntireX Broker started task. EntireX Broker DBID# CUST ATTR Complete APPLICATION SERVERS TCP/IPFirewall Client TCP/IP Stack Client Application Code ADABAS PORT#

15. The next piece to the puzzle is the client Broker stub. This broker stub is provided by Software AG on the EntireX CD. The broker stub is specific to each Windows NT or UNIX environment. EntireX Broker DBID# CUST ATTR Complete APPLICATION SERVERS TCP/IPFirewall Client TCP/IP Stack Client Application Code ADABAS PORT# BROKER STUB

16. The next piece is to add the Firewall IP address and port# to the network Domain Name Service and /etc/services file. And the puzzle is complete again... EntireX Broker DBID# CUST ATTR Complete APPLICATION SERVERS TCP/IPFirewall Client TCP/IP Stack Client Application Code ADABAS PORT# BROKER STUB DNS UPATES

17. So let me review a little bit. The basic application logic flow is... Application Server in Broker RECV Mode

18. Something on the client side initiates a SEND to Broker followed *immediately* by a RECV. Application Server in Broker RECV Mode Client CALL Broker (now in RECV mode)

19. The application server READs or UPDATEs ADABAS or performs some other logic. Application Server in Broker RECV Mode Client CALL Broker (in RECV mode now) Application Logic READ/ UPDATE ADABAS

20. The application server will issue a Broker SEND followed immediately by a Broker RECV. Application Server in Broker RECV Mode Client CALL Broker (in RECV mode now) Application Logic READ/ UPDATE ADABAS Application Server issues a Broker SEND followed by a Broker RECV

21. THAT’S ALL FOLKS...