Networks

So far this book has covered creating channels between your system and any other system with which you need to have communications, and creating multi-hop channels to systems where you have no direct connections. The message channel connections described in the scenarios are shown as a network diagram in Figure 17.

Channel and transmission queue names

You can give transmission queues any name you like, but to avoid confusion, you can give them the same names as the destination queue manager names, or queue manager alias names, as appropriate, to associate them with the route they use. This gives a clear overview of parallel routes that you create through intermediate (multi-hopped) queue managers.

This is not quite so clear-cut for channel names. The channel names in Figure 17 for QM2, for example, must be different for incoming and outgoing channels. All channel names may still contain their transmission queue names, but they must be qualified to make them unique.

For example, at QM2, there is a QM3 channel coming from QM1, and a QM3 channel going to QM3. To make the names unique, the first one may be named 'QM3_from_QM1', and the second may be named 'QM3_from_QM2'. In this way, the channel names show the transmission queue name in the first part of the name, and the direction and adjacent queue manager name in the second part of the name.

A table of suggested channel names for Figure 17 is given in Table 1.

Figure 17. Network diagram showing all channels

Table 1. Example of channel names

Notes:

1. On WebSphere MQ for z/OS, queue manager names are limited to 4 characters.

2. You are strongly recommended to name all the channels in your network uniquely. As shown in Table 1, including the source and target queue manager names in the channel name is a good way to do this.

Network planner

This chapter has discussed application designer, systems administrator, and channel planner functions. Creating a network assumes that there is another, higher level function of network planner whose plans are implemented by the other members of the team.

If an application is used widely, it is more economical to think in terms of local access sites for the concentration of message traffic, using wide-band links between the local access sites, as shown in Figure 18.

In this example there are two main systems and a number of satellite systems (The actual configuration would depend on business considerations.) There are two concentrator queue managers located at convenient centers. Each QM-concentrator has message channels to the local queue managers:

• QM-concentrator 1 has message channels to each of the three local queue managers, QM1, QM2, and QM3. The applications using these queue managers can communicate with each other through the QM-concentrators.
• QM-concentrator 2 has message channels to each of the three local queue managers, QM4, QM5, and QM6. The applications using these queue managers can communicate with each other through the QM-concentrators.
• The QM-concentrators have message channels between themselves thus allowing any application at a queue manager to exchange messages with any other application at another queue manager.

Figure 18. Network diagram showing QM-concentrators