Build high-availability server Load balancer components and cache DNS

As shown in the following figure, this task consists of the high-availability server Load balancer component and cache DNS. High-availability server Load balancer component requirements: optimize some key links in the business system architecture, load balancing for TCP layer data traffic, and ensure high service availability. Technology Selection: HAProxy + Keepalived, which are common and mature combinations. In addition

As shown in the following figure, this task consists of the high-availability server Load balancer component and cache DNS. High-availability server Load balancer component requirements: optimize some key links in the business system architecture, load balancing for TCP layer data traffic, and ensure high service availability. Technology Selection: HAProxy + Keepalived, which are common and mature combinations. In addition

As shown in the following figure, this task consists of the high-availability server Load balancer component and cache DNS.

High-availability Load Balancing Components

Requirement: optimize some key links in the business system architecture, perform Load Balancing for TCP layer data traffic, and ensure high service availability.

Technology Selection: HAProxy + Keepalived, which are common and mature combinations.

In addition, because HAProxy has many Load Balancing tasks and manual Configuration modification is not reliable to add, delete, and modify tasks, a simple HAProxy management system is implemented, in the future, the source code will be open for verification and improvement.

Cache DNS

Take www.qq.com as an example to explain the domain name resolution process:

1. the user initiates a request for www.qq.com. query to the Local DNS;

2. Local DNS initiates a com. query request to the root server;

3. The root server returns the com. Resolution record to the Local DNS;

4. The Local DNS initiates a qq.com. query request to the com. authoritative server;

5.com. the authoritative server returns the qq.com. Resolution record to the Local DNS;

6. The Local DNS initiates a request for www.qq.com. query to the qq.com. authoritative server;

7.qq.com. the authoritative server returns the www.qq.com. Resolution record to the Local DNS;

8. The Local DNS returns the www.qq.com resolution record to the user.

Local DNS is generally provided by network operators (such as China Telecom and China Netcom.

The cache DNS is between the client (this is a relative concept) and the local DNS, and uses the cache function of the DNS server software and the close-up characteristics between the cache DNS and the client to accelerate domain name resolution.

You can also perform Domain Name Hijacking on the cache DNS as needed. For profit, the operator will also perform Domain Name Hijacking on the local DNS, which is a big problem for Internet companies to provide external services.

After completing the work, I wrote a installation configuration document for reference by other colleagues. For more information, see haproxy?haproxy=le=keepalived=bindassemblies.

Original article address: Build a high-availability server Load balancer component and cache DNS. Thank you for sharing it with me.