Copyright © TIBCO Software Inc. All Rights Reserved


Chapter 2 Creating a TIBCO Silver Fabric Enabler for Adapter for SAP Stack : TIBCO Silver Fabric Engine Statistics

TIBCO Silver Fabric Engine Statistics
If you want TIBCO® Adapter for SAP Components to scale (add new Engines) automatically, you can define rules that add or remove TIBCO Silver® Fabric engines based on engine statistics Adapter for SAP component statistics.
Data collected are aggregated. The aggregate is used to average raw statistic values by using a source ID. The average is calculated by individually averaging the statistic values for each source ID (for each Engine), and then averaging the results across all Engines.
For example, if a specific aggregated value triggers the rule, but the normalized geometric variance across the Engines is less than 0.85, then it does not add an Engine. Removing Engines is not affected by variance.
You can set up Enablement Condition rules. The Engine will start when conditions specified are met by statistical values reported by other Engines.
You also can setup rules on threshold activation, which is a statistic on the Engine itself or other Engines.
 
Task A Set Threshold Activation and Enablement Conditions for a Stack
1.
2.
Select Threshold Activation or Enablement Condition in the Add A Rule list.
Figure 8 Creating a new Threshold Activation Rule
3.
If you select Threshold Activation, specify the following parameters in the Create Threshold Activation Rule panel:
In Condition Type list: select the Component Statistic item.
In the Action list, select Add Engine or Remove Engine.
 
Statistics consist of engine and machine measures that are independent of TIBCO® Adapter for SAP and any other statistical information gathered from the Adapter for SAP via TIBCO Hawk ® when that is applicable.
You can see the statistics that are tracked by the component created to publish the Adapter for SAP by selecting that component in the rule creation window.
Create Archive Scaling Rules
You can define stacks that can add or remove component archives based on archive statistics that are monitored for triggering conditions.
Create archive scaling rules to automate creation or removal of new Adapter for SAP Component Archives when rules based on archive statistics meet or exceed thresholds or conditions you have set.
After adding components to your stack you can create new scaling rules by opening the Archive Scaling tab and clicking the Create New button.
Name your new archive scaling rule and give it a description to help you and others quickly identify the purpose and content of your archive scaling rule.
The Archives tab defines what archive is added or removed according to the rules you define in the other tabs.
Use the Add icon at the right of the column heading row to add one or more archives (process instances) to be scaled up or down in your stack.
Select the Adapter for SAP component that was used to upload the application archive file and use the Archive Names field to specify what archive is subject to the rules you set using the other tabs of the Archive Scaling Rule Editor.
Use the Add Archive Conditions tab and click the Add icon to the right of the column heading row to create and define a new Add Archive rule.
Select the statistics, the operator, the value, and the sampling window period in seconds to define your condition for adding a new archive instance.
You can define more than one rule. With more than one rule, set the Satisfies field to specify whether all rules must be satisfied or whether any one rule can be satisfied to trigger addition of a new archive instance.
Optionally you can set a preference for running new archives or new process instances on component instances with favorable usage profiles. Select the statistic that is most relevant to your implementation and you can create new process instances there according to those conditions you defined.
The Remove Archive Conditions tab enables you to release computing resources and remove unused or idle Component Archives or process instances to scale down your Component Archives just as you scaled them up according to conditions you define on usage statistics.
With the Target Component Conditions tab, you can restrict the start of new Archive instances to those machines that have the same set of resources that you choose. Set a rule or several rules with statistics, operators, and values as you would on the Add Archive Conditions tab and further restrict where the new Archive instances can start depending on component Instances that have:
Same Component: works all the time for Component Archive scaling.
From the set of Components: works only if your Component Archive is compatible with the set of components present. For example an Adapter for SAP archive can scale on an Adapter Component.
Same Component Type: the process archive has the possibility of being scaled up on different versions of the product
Same Enabler: components that require a specific enabler should use this option.
Same Middleware Version: this selection ensures that the Component Archive runs on machines with the appropriate middle ware: TIBCO Adapter for SAP, TIBCO TRA, TIBCO Hawk, etc.
Same Enabler and Middleware Version: this selection ensures that your Component Archive scales up successfully, but it is the least restrictive of the target component conditions. .
Provided that the Component Archive has the proper Component Type, TIBCO Silver Fabric can usually find the correct computing environment for scaling up. For example, for an Adapter for SAP Component Archive, a selection of the "Same Component Type" ensures that the Silver Fabric Broker tries and finds an engine with same Adapter for SAP Component Type on which to run new Adapter for SAP Component Archives.
 
 

Copyright © TIBCO Software Inc. All Rights Reserved