Attribute-based linked tries for rule evaluation

• US 8,732,207 B2
• Filed: 07/02/2012
• Issued: 05/20/2014
• Est. Priority Date: 07/02/2012
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Ramakrishnan, Arun, Shetty, Rohit
• Primary Examiner(s): Vy, Hung T
• Application Number:
  US13/539,748
• Publication Number:
  US 20140006455A1
• Time in Patent Office: 687 Days
• Field of Search: 707/797, 707/790, 706/47, 706/45
• US Class Current: 707/797
• CPC Class Codes: G06F 16/90344 by using string matching techniques
• CPC Class Codes: G06F 2209/543 Local

Abstract

An embodiment for evaluating rules pertaining to an event includes providing a rule trie comprising multiple nodes, wherein match conditions must be met to trigger a given rule, and each match condition corresponds to a different node. An attribute trie is provided for a string attribute, which includes a node sequence having a value. The string attribute is extracted from the event and also has a value. The value of the extracted string attribute and the value of the node sequence are compared, by traversing a path extending along the node sequence. Responsive to determining that the values of the extracted string attribute and the node sequence are the same, notice is provided that the match condition of a particular node of the rule trie has been met by an attribute of the received event.

Claims

1. A computer implemented method for evaluating one or more rules that pertain to an event having a string attribute, said method comprising the steps of:

providing a rule trie comprising a number of nodes, wherein one or more match conditions must be met to trigger a given rule, and each match condition corresponds to a different node of the rule trie;

providing a string attribute trie for the string attribute, wherein the string attribute trie includes a node sequence that is associated with a particular value that is a match condition of a particular node of the rule trie;

configuring a link between a specified node of the node sequence of the string attribute trie, and the particular node of the rule trie;

responsive to receiving the event, extracting the string attribute from the event, wherein the extracted string attribute has a value;

comparing the value of the extracted string attribute with the associated value of the node sequence, by traversing a path that extends along the node sequence; and

responsive to determining that the value of the extracted string attribute and the associated value of the node sequence are the same, using the configured link to send notice that the match condition of the particular node of the rule trie has been met by the extracted string attribute of the received event.

2. The method of claim 1, wherein:

the extracted string attribute and the node sequence of the string attribute trie each comprises a sequence of alphanumeric characters, and the value of the extracted string attribute is compared by comparing each character of the extracted string attribute with a corresponding character of the node sequence.

3. The method of claim 1, wherein:

an attribute trie is used to extract each string attribute from the received event.

4. The method of claim 1, wherein:

the node sequence included in the string attribute trie comprises one of multiple node sequences that are included in one or a plurality of string attribute tries, selectively, and each node sequence corresponds to a different node of the rule trie, and has an associated value that matches the match condition of its corresponding rule trie node.

5. The method of claim 4, wherein:

a link is provided from an end node of each node sequence to the corresponding rule trie node thereof, for use in notifying the rule trie node when its match condition is met by an attribute of the received event.

6. The method of claim 4, wherein:

subsequent to traversing each of the node sequences, each rule that has had a prespecified combination, or a prespecified one, selectively, of its match conditions met is triggered.

7. The method of claim 1, wherein:

subsequent to traversing each node sequence included in an attribute trie, it is determined whether the received event includes any attributes that are not string attributes.

8. The method of claim 1, wherein:

responsive to determining that the received event includes one or more attributes that are not string events, the received event is evaluated against the rule trie.

9. The method of claim 1, wherein:

the match condition of at least one of the rule trie nodes comprises a numeric match condition.

10. The method of claim 9, wherein:

the method includes determining whether each numeric match condition has been met by an attribute of the received event.