NodeBrain  Demonstration Site
A Rule Engine for State and Event Monitoring     


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This site provides simple demonstrations of the NodeBrain Rule Engine described at to quickly introduce you to the concepts. You are encouraged to modify the demonstration rules and transactions to experiment and test your understanding.


The demonstrations on this site run in a restricted mode that prevents you from using:

  1. host shell commands,
  2. source commands, and
  3. modules other than Table and Cache.
These restrictions prevent the rule engine from interacting with the host environment, making it useless for any purpose other than demonstrating how the rule engine makes decisions. We are not able to demonstrate here how the rule engine gets input from a variety of sources, or how it responds by interacting with the host or remote instances of the rule engine.

Rules and Transactions

Input to the rule engine for each demonstration is divided into Rules and Transactions. You may modify either or both of these inputs before rerunning a demonstration. In some applications rules are relatively static and managed under version control. Rules are normally loaded by the rule engine at startup, so you should think about the demonstration rules in this way. To be useful, all applications need one or more, often many, dynamic streams of transactions. The ALERT and ASSERT commands are the most common transactions, but any command may be processed as a transaction, including DEFINE, REDEFINE, and UNDEFINE commands that modify the rules. So think of demonstration transactions as the information input to the rule engine after startup.


In addition to the restrictions listed above, the design of this site prevents illustrations of many time related conditions. This is because the transactions are flushed through the rule engine quickly, so timers don't have an opportunity to expire. This deficiency will be resolved in a future update to this site.


You can navigate through the demonstration scenarios using [Next], [Prior] and [Up] links on each page. Each demonstration also has a [Run] button to run it again after modifications, and a [Reset] link to undo all your modification and run the demonstration with the original rules and transactions. If you return to this page in the future, use the link in the upper right portion of the page to the start the demonstration.