Prerequisite -> Implementing a Tier Management Scheme
Example 134 - Rating: advanced
Example 134 - Rating: advanced
| The Things that Make Up this Example | To Execute this Example |
This example demonstrates a small set of system variables that can be used to implement an example of a tier management scheme.
Applications that use a tier management scheme like this can be used anywhere in LANSA (eg: Visual LANSA, LANSA for the Web, LANSA for iSeries green screen applications, etc). The implementation just uses system variables and normal RDML functions.
An example form named VL_SAM134 (shown) is used to define and manage the physical systems used to actually implement the logical tiers at execution time.
Most typically only one (standalone) or two (a client and a server) physical systems are used at execution time, but you can use VL_SAM134 to configure and implement "n" tier application schemes without having to change a single line of an application that uses the scheme.
If you are interested in understanding this example tier management scheme then you should not worry too much about the precise details at this stage.
Subsequent examples in this section demonstrate how this tier management scheme has been implemented and what benefit it delivers .
Actually implementing and executing the following examples is the quickest and easiest way to understand tier management issues in general and this example tier scheme in particular.
Note: This example tier management scheme uses four logical tiers to represent common commercial level IT application resource requirements. If you chose to implement a scheme like this you could of course have more tiers, less tiers, or tiers with different names. What you should avoid is tiers that are in any way directly linked to physical locations. Tiers are conceptual objects that involve a place you go to access a certain kind of resource (eg: *CAFÉ_TIER, *THEATRE_TIER, *SHOPPING_TIER). Where the tier is physically located is something that is determined at execution time. When in London the *THEATRE_TIER would be in the West End, but in New York it would be in Broadway.
Keywords
Applications that use a tier management scheme like this can be used anywhere in LANSA (eg: Visual LANSA, LANSA for the Web, LANSA for iSeries green screen applications, etc). The implementation just uses system variables and normal RDML functions.
An example form named VL_SAM134 (shown) is used to define and manage the physical systems used to actually implement the logical tiers at execution time.
Most typically only one (standalone) or two (a client and a server) physical systems are used at execution time, but you can use VL_SAM134 to configure and implement "n" tier application schemes without having to change a single line of an application that uses the scheme.
If you are interested in understanding this example tier management scheme then you should not worry too much about the precise details at this stage.
Subsequent examples in this section demonstrate how this tier management scheme has been implemented and what benefit it delivers .
Actually implementing and executing the following examples is the quickest and easiest way to understand tier management issues in general and this example tier scheme in particular.
Note: This example tier management scheme uses four logical tiers to represent common commercial level IT application resource requirements. If you chose to implement a scheme like this you could of course have more tiers, less tiers, or tiers with different names. What you should avoid is tiers that are in any way directly linked to physical locations. Tiers are conceptual objects that involve a place you go to access a certain kind of resource (eg: *CAFÉ_TIER, *THEATRE_TIER, *SHOPPING_TIER). Where the tier is physically located is something that is determined at execution time. When in London the *THEATRE_TIER would be in the West End, but in New York it would be in Broadway.
Keywords
| Tier | Management |
| Multi Tier | Remote Procedure |
| Database | Client |
| Server | n Tier - |
| Example 134 |