Database shadowing

Many Adager users throughout the world shadow their IMAGE/SQL database transactions, either from one HP3000 to another HP3000, or within the same HP3000 system. The most powerful shadowing engine is Netbase from Quest Software (or SharePlex/iX if you acquired Netbase through Hewlett-Packard). As a result of a coordinated project, Adager and Quest have enhanced both of their products to allow their mutual users to also shadow their Adager database transformations and relieve them from the burden of managing duplicate database maintenance. In this month's column I discuss the steps involved to accomplish this.

Prerequisites

All of your systems involved must be licensed to run Adager and Netbase, and you must have at least Adager version 950101 and Netbase version 9.6.

Once Adager and Netbase are installed on the systems, what else do I need?

Netbase traps all of the relevant calls to the system's SL, XL and NL and attempts to replicate the configured ones on the shadow system. Netbase replicates the Adager database transformations by replicating the Adager run on the shadow database. For now, Netbase only replicates those Adager transformations performed in batch in the master system by launching a synchronized JobStream on the shadow system.

The first step in preparing both of your systems to shadow Adager transformations is to exclude Adager from the automatic Netbase shadowing by doing:

Run NBDIR.PUB.NETBASE

D> PROGRAM @.@.REGO;NONB

D> EXIT

This command tells Netbase not to shadow any native-mode calls which originate from programs (or NMXL modules) which reside in the Rego account.

The next step is to update your Netbase system configuration in both systems by using your favorite editor to add the following lines to the ALLOCATE.DATA.NETBASE file:

EDITOR

> T ALLOCATE.DATA.NETBASE

> ADD

5 ADAGER.PUB.REGO

6 ADAGER77.PUB.REGO

7 ADAGER79.PUB.REGO

//

> K;E

After having added these lines and having saved the
ALLOCATE.DATA.NETBASE file, update your Netbase configuration on both systems by doing:

:Run NBVERS.PUB.NETBASE,DISABLE

:Run NBVERS.PUB.NETBASE,ENABLE

These steps stop Adager's compatibility mode front end (and its co-processors) from going through Netbase's SL located in PUB.SYS and allow them to go directly to the system SL.

The final step is to add the NBADAGER program to the Netbase directory by doing:

Run NBDIR.PUB.NETBASE

D> PROGRAM NBADAGER.PUB.NETBASE;NONB

D> EXIT

How do I shadow my Adager jobstreams from the Master system on to the Shadow system?

As of Adager version 950101 and Netbase version 9.6, Adager jobstreams executed on the Master system will automatically execute on the Shadow system, provided the Adager JobStreams are created via the ADAGER.PUB.NETBASE command file.

When you execute the ADAGER.PUB.NETBASE command file, your system runs Adager with Parm=8 to create a standard Adager JobStream and then runs NBADAGER.PUB.NETBASE to complete the Adager-produced JobStream. Using this command file makes this process very simple for you.

After you prepare an Adager JobStream and submit it for execution, Netbase checks that the Adager run is successful in your master system. If it is, it automatically launches the corresponding Adager job in the shadow system. If it isn't, it advises you of the reason for the failure.

The command file ADAGER.PUB.NETBASE must be used to create the jobstream and only one database can be modified with each execution of this command file.

Currently, any Adager database changes made in session mode will NOT be shadowed automatically by Netbase.

Can old Adager jobstreams be shadowed by Netbase?

Yes, they can. To modify existing Adager JobStream files to automatically replicate on the shadow system please do the following: