Nlb+application Request Route Network Load Balancing

Preface

In the previous article configuring IIS load Balancing We used the Microsoft Arr, and I mentioned the high availability of the site in that article, but Arr can only do the request Portal Message Distribution service, so if our message distributor is down, then a lot of application service clusters are in vain.

This article I mainly to solve this problem to do analysis, the introduction of NLB, compared to arr, arr is an application-level load balancing scheme, and NLB is a server-level load balancing scheme.

If Microsoft's two solutions are used together, it's the perfect match for Microsoft's highly available Web site solution.

Application Request route and NLB high-availability scenario evolution

First said application Request Route, his specific implementation plan, I have in my previous article has described, you can understand, here I have a picture to do a brief introduction.

ARR can detect if your IIS app is available and load-balance the user's request, distributing the user's request to the application server, based on our configured load balancing algorithm.

However, if our ARR server is down, our entire application cannot be used, and not up to the high-availability requirements of 24*7 with no downtime.

The following is a Network Load balancing scheme that is shown as NLB

NLB can be configured up to 32 servers, 32 servers by having their own independent IP, there is a virtual IP, user access to the virtual Ip,nlb cluster based on the configured load algorithm to determine the user's request distribution to that application server, if an NLB server down, It does not affect the distribution of messages up to 7 * 24 hours without a high-availability scenario.

However, NLB cannot detect if your IIS Web site is down and only detects that the server is down, so that if your IIS Web site has stopped, NLB will return the request to the user, so the hassle can come.

So how do we use Microsoft's technology to make the site highly available? Yes, that's nlb+application Request Route.

The user requests the virtual IP, the Access NLB,NLB detects an available server, and the request is sent to Arr,arr to dispose of the user's request to the website that is available for detection. In the mouth!! In the mouth!! Diao!!!

Installation configuration for NLB

Open the Windows Server, go to the Server management interface, select Features, and then add features.

After installing, open the Network load balancer

New cluster, first you in your local area network, find a non-used IP as your cluster's virtual IP.

Set the priority, the smaller the priority number, the higher the representation.

Add a cluster IP that is, you have checked the LAN does not exist in an IP address, he is the virtual IP in the figure.

Set the port that requires cluster load and then set the protocol, distribution form.

Then add a server to the cluster.

This will be a success. is so simple.

So we're going to look at the relevance of the filter pattern.

None: Join a B two server, request distribution is this: Abababababab .....

Single: Join A, b two server, request distribution is this: Aaaaaaaaaaaaaaaaa ..... Or bbbbbbbbbbb ....

Network: According to the IP Class C screen to decide which server to handle, that is, a server will only handle requests from some network segment c. This approach ensures that clients that use multiple proxies can be directed to the same server.

Single host: One of the highest-priority available servers handles the user requests that are said.

Disable this port range: The configured port range is not forwarded and the remaining is done.

Show the effect

53 server, Access virtual ip176, get content to 121 server.

Simulate 100 users, send 1000 requests virtual cluster IP, yellow access is 121 server, white is 122 server, the correlation is none.

This article is here, the other test results do not show one by one, sit down, feel more profound points.

Summarize

If you are using these techniques in your development process, or if you want to use any of the problems encountered, welcome to the upper left corner of the group, we discuss learning together.

Nlb+application Request Route Network Load Balancing