Mainframe Testing

Mainframe

mainframes are high-performance computers (ASP 400 –IBM) with large amounts of memory and processors that process billions of simple calculations and transactions in real time. The mainframe is critical to commercial databases, transaction servers, and applications that require high resiliency, security, and agility.

Mainframe testing
Mainframe testing is connected with two main concepts.

1. Outbound transfer
2. Inbound transfer

Outbound transfer
As the name suggests outbound transfer means transferring files from mainframe to the outside(Applications). In a real world application we don’t transfer a single file during a transaction mostly it is bulk of files (batch processing).

Inbound transfer
This is the opposite of outbound transfer. Files are transferring from outside (Applications) to mainframe.

Testing Methodologies
Mainframe testing is like any other testing procedure starting from Requirement gathering, test design, test execution and result reporting. Mainframe application testing is a time taking process. A clear test schedule should be followed for test design, data setup and execution.

In mainframe testing we are using manual testing technique. Because we have to determine files are transferred successfully or not. We can’t necessarily do this with automation tools. But there are tools we can do this, it depends on our requirements.
According to the requirements we have to choose whether we are testing for a single file or batch of files. In most of the cases it is batch of files. But in some cases you have to perform a test case for a single test file.

In Mainframe testing, the Software or an application are retrieved by end-users in a way, which is diverse from Web applications.
And the application tester should know these significant differences, which are shown below:

Web Applications
The web applications are acquired via two-tier architecture [Client/Server] or three-tier architecture [Presentation/apps/DB storage layers]
The web applications retrieve across Browser or UI.
In this, the testing can be performed straight on the application screen.

Mainframe Applications
In the mainframe application, the end-user must log into the system directly.
Terminal Emulator must retrieve the web applications.
In this, the tester should have precise knowledge of mainframe operations.

Test Cases
• Outbound transfer
Steps

1. x.dat is sending from mainframe to application
2. x.dat file trigger the daemon program
3. x.dat file send via the gateway
4. Verify the delivery notifications.

• Inbound transfer
Steps

1. Trigger x.ack file from application to gateway
2. Verify the file is present in input directory.
3. Verify the file moved to the Archive directory

Common issues occurring in mainframe testing

1. I/O error
   Reading at the end of the file, file length error, attempt to write into read-only file.

2. Error occurred during OPEN
   Gateway is down

3. Operation Exception
   Unable to open file, missing DD card