Disaster Recovery Assistance for Twinax Users
The Best Way to Keep Twinax Users Working is with a Pure TCP/IP Controller
In most disaster recovery scenarios these days TCP/IP is the protocol of choice for switching between machines. Most solutions to switch users from the primary AS/400 to the back-up AS/400 require that the IP address under which the AS/400 appears be changed. For example, say that the production AS/400 has IP address 10.1.1.10, while the back-up AS/400 normally uses 10.1.1.20. In the event of a disaster, the back-up AS/400 switches to 10.1.1.10. All the PC users using TN5250 do not have to change their settings; they simply restart their sessions and sign back on.
What Happens to Twinax Users?
In the same scenario, Twinax users suffer a harsher plight. During disaster recovery the local Twinax users can be left without any access to the back-up AS/400. Remote Twinax users usually can be switched over using some scripts on the AS/400, however is often a challenge.
Is There a Better Way?
IP-based Twinax controllers like the e-Twin@x Controller can easily switch between AS/400’s because they treat Twinax users the same way they treat the PC users, once the session is reset. The e-Twin@x Controller, as a matter of fact, does this automatically; the users can sign on to the back-up AS/400 and continue to work, without any operator intervention!
What About Locally Attached Twinax Users?
Even locally attached Twinax users can work in this fashion, using the 47xx local e-Twin@x Controller series. These very aggressively priced controllers are designed to work in a local Twinax environment. All the local Twinax cables connect into the 47xx Controller in place of the local Twinax controller resident in the AS/400. The 47xx connects to the AS/400 over the built-in 10/100 MHz Ethernet card, ensuring fast response times. The 47xx Controller will switch over to the back-up AS/400, provided it is on the same IP subnet as the production machine.
Special Features for Switch-Over
The e-Twin@x Controller includes the following special features, which are especially relevant for disaster recovery situations:
DNS Look Up
The e-Twin@x Controller has the ability to configure the AS/400 via a DNS name instead of IP address. A timer in the e-Twin@x Controller refreshes the DNS look up every time it expires. This way, the System Administrator changes the internal DNS server, which lists the AS/400 domain name, and after the timer expires, all the devices are automatically changed to the new IP address.
Auto Reconnect
If the connection to the AS/400 is lost, the e-Twin@x Controller tries to re-establish the connection, without user intervention, after a predetermined time-out period.
Default Rollover
Two AS/400’s can be configured to act as default and back-up, respectively. When the primary (default) AS/400 can no longer be accessed, the e-Twin@x Controller automatically attempts to connect to the secondary (back-up) AS/400. After successful connection to the back-up AS/400, it will stay connected to that AS/400 until the e-Twin@x Controller is reset, which can be done by using a Web browser.
By the way, you can define that the process be reversed if the first host is also defined as a backup system (for the secondary host). In this case, if the backup system fails (or if the TCP/IP interface is terminated), all sessions will be re-connected to the primary system.
For More Information
- For more information about the e-Twin@x Controller, visit www.e-twinaxcontroller.com.
- Click here to register for a 30-day demo unit!
- This white paper is also available in PDF format. To download a copy, click here.
|
