WS-Discovery Redundancy Attributes for Server Failover
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing communication systems between servers and client stations lack transparency and automatic failover mechanisms, making it difficult to seamlessly transition from an active server to a standby server when the active server becomes inactive.
Innovation Solution
Implementing the Web Services Dynamic Discovery (WS-Discovery) protocol with additional redundancy attributes in messages to enable automatic and transparent election of a standby server as the new active server, using messages like 'Hello+' with fields such as 'Unique ID', 'MessageType', 'Priority', and 'AdvertisementTimeout' to manage server redundancy and maintain continuous communication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a standby server is configured to replace an inactive active server, then service continuity is improved, but the complexity of server management and configuration increases
Solution Approach 1:
The standby server is pre-configured with the capability to assume the active server role, including pre-assigning the floating IP address and preparing the redundancy attribute. When the active server fails, the standby server can immediately take over without requiring complex manual reconfiguration, thus maintaining service continuity while reducing management complexity.
Solution Approach 2:
The system implements a health check mechanism where the active server periodically sends messages to the standby server to indicate its active status. The standby server monitors these messages and automatically triggers failover when messages are not received within a determined time interval. This feedback loop automates the failover process, reducing the need for complex manual management.
2Ease of operation
If manual intervention is required for server failover, then control over the transition process is improved, but the time required for failover and service interruption increases
Solution Approach 1:
The standby server autonomously monitors the active server's health through periodic message reception and automatically executes the failover process when the active server becomes inactive. The system uses the redundancy attribute and determined time interval to self-determine when failover is necessary, eliminating the need for manual intervention and reducing failover time while maintaining controlled transitions.
3Ease of operation
If the failover process is made transparent to client stations, then ease of operation is improved, but the complexity of the server communication protocol increases
Solution Approach 1:
The floating IP address serves as an intermediary between the server infrastructure and client stations. When failover occurs, only the floating IP address changes association between physical servers, while client stations continue to communicate using the same IP address. This abstracts the complexity of server replacement from clients, making failover transparent while the protocol handles the complexity of IP address reassignment and server coordination in the background.
4Reliability
If periodic health check messages are transmitted, then reliability of failover detection is improved, but network traffic and energy consumption increase
Solution Approach 1:
The active server transmits health check messages at periodic intervals to the standby server. This periodic transmission provides reliable failover detection while allowing the system to enter low-power states between transmissions. The determined time interval is optimized to balance detection reliability with energy consumption, sending messages frequently enough to detect failures promptly but not so frequently as to waste energy.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a method for communication between a first server (S1) and a second server (S2), the first server (S1) being designated as an active server for communicating with one or more client stations (C1, C2, C3) via a network, wherein said method is based on the use of messages consistent with the Web Services Dynamic Discovery (WS-Discovery) specification, and is characterized in that the messages include an additional redundancy attribute for electing the second server (S2) as an active server when the first server (S1) is no longer an active server.