Packet Forwarding Engine Statistics Replication During Switchover
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In redundant routing systems, maintaining accurate traffic statistics during a switchover between primary and backup routing engines is challenging due to potential discrepancies and the resulting steady-state load, which affects router performance.
Innovation Solution
A method where the backup routing engine requests and stores traffic statistics from the primary engine, resets counters, and combines this data with duplicated traffic to ensure continuity and minimize load during a switchover.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the backup routing engine independently tracks traffic statistics, then traffic statistics continuity is maintained during switchover, but steady-state load increases affecting router performance
Solution Approach 1:
The backup routing engine performs preliminary actions by requesting and storing traffic statistics from the primary engine before switchover occurs. This advance preparation ensures that when switchover happens, the backup engine already has the necessary statistical data, eliminating the need for continuous independent tracking and reducing steady-state load during normal operation.
2Measurement precision
If the backup routing engine requests traffic statistics frequently, then accurate traffic statistics are maintained, but steady-state load increases
Solution Approach 1:
Instead of continuous or frequent requests, the system implements periodic action by having the backup routing engine request traffic statistics at specific intervals or triggers (such as before switchover). This periodic approach maintains sufficient statistical accuracy while significantly reducing the steady-state load compared to continuous tracking, optimizing the balance between measurement precision and system performance.
Data Source
Figure 1A
Figure 1B
Figure 1C
AI summary
In some implementations, a first processing component of a network device may receive first traffic data obtained by a second processing component of the network device. The first processing component may store the first traffic data as residual statistics. The first processing component may obtain second traffic data associated with a copy of a traffic stream processed by the first processing component based on storing the first traffic data as the residual statistics. The first processing component may perform a switchover from the second processing component to the first processing component. The first processing component may determine current traffic data based on the residual statistics and the second traffic data. The current traffic data may be determined based on performing the switchover from the second processing component to the first processing component.