GSLB TTL Controller Dynamic Load Adjustment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing global server load balancers face challenges in dynamically adjusting cache time-to-live (TTL) values to balance between rapid propagation of DNS changes and maintaining system stability and service quality, as setting TTL too low leads to increased requests and potential system overload, while setting it too high delays state changes in local servers.
Innovation Solution
A method for dynamically updating TTL values in a global server load balancer based on calculated load, using a TTL controller that adjusts the values within a predetermined range, increasing when load exceeds a threshold and decreasing when load is below it, incorporating a DNS query processor, server selector, and load calculator to manage requests and reflect state changes efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If TTL is set to be significantly small or zero, then rapid propagation of DNS record changes is achieved, but the number of requests to GSLB increases causing system overload
Solution Approach 1:
The patent implements dynamic TTL adjustment where the GSLB automatically modifies TTL values based on real-time system load conditions. When load is high, TTL is increased to reduce request frequency; when load is low, TTL is decreased to enable faster propagation. This dynamic adaptation resolves the contradiction by making TTL flexible rather than fixed.
Solution Approach 2:
The system incorporates feedback mechanisms where the GSLB monitors its own load status and uses this information to adjust TTL values accordingly. The load status information feeds back into the TTL determination process, creating a closed-loop control system that balances propagation speed with system stability.
2Loss of time
If TTL is set to be significantly small or zero, then rapid propagation of DNS record changes is achieved, but the GSLB becomes unable to respond to requests in extreme cases
Solution Approach 1:
The patent makes TTL dynamic by adjusting it according to system load conditions. When the GSLB is under heavy load, TTL is increased to reduce the frequency of DNS queries, thereby preserving system response capability. When load is light, TTL is decreased to minimize propagation delay, thus resolving the contradiction between speed and productivity.
3Adaptability or versatility
If TTL is set to be significantly small or zero, then rapid propagation of situation changes is possible, but the number of requests which come in the GSLB is also increased
Solution Approach 1:
The system dynamically adjusts TTL based on load status to balance adaptability with request volume management. By increasing TTL when load is high, the system maintains responsiveness to changes while reducing the quantity of requests. By decreasing TTL when load is low, it enables rapid propagation without overwhelming the system.
Solution Approach 2:
The patent changes the TTL parameter based on system conditions. Instead of using a fixed TTL value, the system modifies this parameter dynamically according to load status, thereby adapting the request frequency to system capacity while maintaining responsiveness to DNS record changes.
Data Source
AI summary
Disclosed are a global server load balancer (GSLB) apparatus and a method for dynamically controlling cache time-to-live (TTL) in the GSLB apparatus. The GSLB apparatus which performs load balancing among a plurality of local servers includes a domain name system (DNS) query processor that receives a query message from a DNS server, a server selector that selects a local server among the plurality of local servers based on the received query message, a load calculator that collects state information of the GSLB apparatus, and calculates a load of the GSLB apparatus from the collected state information, and a TTL controller that updates a TTL of the GSLB apparatus based on the calculated load.