• Fail-safe operation; does the gateway offer load-balancing and backup
• Beyond emulation; does the gateway offer GCOS access for your user-developed client applications
• Security; can you encrypt between your clients and the gateway
• Scalability; if you need more sessions, can the gateway power be increased

Load balancing and back-up

Ggate Professional Edition is licensed by number of concurrent sessions, distributed over multiple servers if desired. The license fee is the same whether all sessions are allocated to a single server or split over multiple servers. When Ggate is installed on multiple servers we recommend that you also install G&R Gproxy on every Ggate server. Gproxy collects statistics about all available Ggate servers in the network and can be used to balance the load between the servers; either equally between the servers or according to an assigned load factor if the hardware capacities of the servers differ. If one or more of the Ggate servers are shut down for maintenance, Gproxy will distribute their licenses to the remaining servers.

Gproxy can be purchased independently per server, but it is also available in the GgatePlus Professional Edition package, which includes Ggate Professional Edition, Gproxy, Gspool and GUFT server. GgatePlus is sold by total number of Ggate sessions, but can be installed on as many servers as necessary. Each server included in the license can run Gspool and GUFT, in addition to Ggate and Gproxy.

Client applications

Both the Windows and Java versions of Glink include script languages and APIs that allow you to automate host interaction and build your own client application with a customized user interface. GlinkAPI and the programmatic interfaces offered in the Host Links product GlAPI allow you also to build server applications that communicate through Ggate to the Bull mainframes.

Security

Ggate can be configured to use SSL between itself and the client to provide security and privacy, using encryption and authentication. This means that all network traffic between your user workstations and Ggate can be encrypted and that you can, if you want, authenticate all your users. The users, who may be your business-partners, can also be sure that they are connecting to your Ggate server, and not something masquerading as your server.

Scalability

Ggate is designed to be robust, scalable and to take advantage of multiprocessor architectures. On Linux and UNIX operating systems each session is an independent process that has no influence on other processes and that at any time can be scheduled by the operating system to execute on the least loaded processor. On Windows systems each session executes as an independent thread with the same benefits. Memory is the most important resource, and as long as there is available memory and network capacity you will be able to utilize the processor power of the Ggate server.

Performance

During Ggate qualification tests on Bull’s new GCOS8 Network Server Processor (GNSP), Bull reached 15,000 concurrent sessions and 2,600 TPS on a single quad-CPU GNSP.