Load balancing (computing): Difference between revisions

Revision as of 16:05, 31 March 2025

Revision as of 16:06, 31 March 2025

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:www.example.org NS two.example.org

However, the zone file for {{mono|www.example.org}} on each server is different such that each server resolves its own IP Address as the A-record.<ref>[http{{Cite web|url=https://www.zytrax.com/books/dns/ch8/a.html|title=Chapter 8 - IPv4 Address Record (A)] Record|website=www.zytrax.com}}</ref> On server ''one'' the zone file for {{mono|www.example.org}} reports:

:@ in a 192.0.2.1

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====Client-side random load balancing====

Another approach to load balancing is to deliver a list of server IPs to the client, and then to have the client randomly select the IP from the list on each connection.<ref>[https://gameserverarchitecture.com/2015/10/pattern-client-side-load-balancing/ Pattern: Client Side Load Balancing]</ref><ref name="ithare">[{{Cite web|url=http://ithare.com/chapter-vib-server-side-architecture-front-end-servers-and-client-side-random-load-balancing/ MMOG |title=Server-Side Architecture. Front-End Servers and Client-Side Random Load Balancing]|date=December 28, 2015|website=IT Hare on Soft.ware}}</ref> This essentially relies on all clients generating similar loads, and the [[Law of Large Numbers]]<ref name="ithare" /> to achieve a reasonably flat load distribution across servers. It has been claimed that client-side random load balancing tends to provide better load distribution than round-robin DNS; this has been attributed to caching issues with round-robin DNS, that in the case of large DNS caching servers, tend to skew the distribution for round-robin DNS, while client-side random selection remains unaffected regardless of DNS caching.<ref name="ithare" />

With this approach, the method of delivery of a list of IPs to the client can vary and may be implemented as a DNS list (delivered to all the clients without any round-robin), or via hardcoding it to the list. If a "smart client" is used, detecting that a randomly selected server is down and connecting randomly again, it also provides [[fault tolerance]].