1. Home
  2. Cloud Computing
  3. Microsoft: How to fix Load Balancer not working in Round-robin fashion for your Cloud Service

Microsoft: How to fix Load Balancer not working in Round-robin fashion for your Cloud Service


I recently came across a case where customer has an issue that the Load balancer of his cloud service is not working in round robin basis. He confirmed that by seeing more number of requests going to few instances whereas the other instances are getting very less number of requests. To analyse the issue, we have collected the IIS logs from all the instances( Customer has 7 instances) and when we parsed the logs, we could be able to confirm the same that 2 instances are getting very less number of requests than the other 5 instances.

How Load Balancer works?

Load balancer uses 5 tuple algorithm to distribute client requests by default. This algorithm is a 5 tuple (source IP, source port, destination IP, destination port, protocol type) hash to map traffic to available servers. It provides stickiness only within a transport session. Packets in the same TCP or UDP session will be directed to the same datacenter IP (DIP) instance behind the load balanced endpoint. When the client closes and re-opens the connection or starts a new session from the same source IP, the source port changes and causes the traffic to go to a different DIP endpoint.

If most of the load goes to a single instance, the number one reason is due to the testing client creating and reusing the same TCP connections. The Azure loadbalancer does round robin load balancing for new incoming TCP connections, not for new incoming HTTP requests. So when a client makes the first request to the cloudapp.net URL, the LB sees an incoming TCP connection and routes it to the next instance in the LB rotation, and then the TCP connection is established between the client and the server.  Depending on the client app, all future HTTP traffic from that client will may go over the same TCP connection or a new TCP connection.

Read the entire article here, How to fix Load Balancer not working in Round-robin fashion for your Cloud Service – Microsoft Azure Cloud Integration Engineering

via the fine folks at Microsoft

Microsoft Founded in 1975, Microsoft (Nasdaq “MSFT”) is the worldwide leader in software, services, devices and solutions that help people and businesses realize their full potential.

Featured Resources:

Related Articles:


White Papers

‘All You Need to Know About Microsoft Windows Nano Server’ Veeam White Paper

Now updated for Windows Server 2016 GA release! You probably heard about Windows Nano Server already … but what is it exactly, and how do you get started with it? What value will it bring to your environment? Nano Server is a headless, 64-bit only deployment option for Windows Server 2016. Microsoft created this component specifically with […]


Download Commvault VM Backup and Recovery: end-to-end VM backup, recovery and cloud management

Commvault’s ability to provide end-to-end VM backup, recovery and cloud management creates a significantly better way to build, protect and optimize VMs throughout their lifecycle. Our best-in-class software for VM backup, recovery and cloud management delivers a number of significant benefits, including: VM recovery with live recovery options; backup to and in the cloud; custom-fit […]

On-Demand Webinars

Architecting for today’s desktop environments – FSLogix On-Demand Webinar

October 19, 2017 Webinar with David Young, Solutions Architect and Product Champion, and Brandon Lee, Solutions Marketer. Video Recording of a live demo of FSLogix and an overview of the latest release of FSLogix Apps featuring Roaming XenApp Email Search and OneDrive App along with Skype for Business Global Address List and Device Based Licensing. […]

Latest Videos

Current State of EUC – E2EVC Video

Session from @E2EVC 2017 Orlando. For event information please visit www.e2evc.com/home. For slides, additional info etc please contact the presenter directly on Twitter. For best video and sound quality do visit the event! This video is from the fine folks at E2EVC Conference

Views All IT News on DABCC.com
Views All IT Videos on DABCC.com
Win a Tesla P100D

Visit Our Sponsors