How to deploy load balancing? Practical steps and precautions

in high concurrent business scenarios, a single server is often difficult to carry massive user requests, system response is slow, service interruption and other issues occur frequently, and load balancing, as a core component of a distributed architecture, can reasonably distribute traffic to multiple backend servers, effectively improving the availability and scalability of the system. This article will disassemble the whole process of load balancing deployment in detail from a practical perspective, and share key considerations to help technicians avoid deployment errors and create a stable and efficient business architecture.

What should be done before load balance deployment?

before the load balance deployment is officially launched, adequate preparation can greatly reduce the deployment risk and ensure the smooth progress of the subsequent process.

1, clear business requirements and architecture planning

need to sort out the core metrics such as the peak concurrency, request type, and data transmission volume of the business to determine the performance requirements of load balancing. For example, high concurrent e-commerce scenarios need to select load balancing devices that support millions of connections. At the same time, it is necessary to plan the scale of the back-end server cluster, network topology, and clarify the deployment location of the load balancing device. Whether it is placed behind the firewall or as an edge entry node.

2, complete the preparation of software and hardware environment

the hardware level, if you choose hardware load balance, you need to purchase the corresponding model of equipment in advance and complete the shelf debugging; if you use software load balance, you need to prepare the required server resources to ensure that the CPU, memory and bandwidth meet the running requirements. At the software level, you need to download the load balance software package of the adaptation system version, such as Nginx, HAProxy, etc., and prepare the operating system and application mirror of the back-end server to ensure that all node environments are unified.

2. The practical operation steps of the mainstream deployment mode of load balance

load balancing has a variety of deployment modes, different modes are suitable for different business scenarios, the following describes the specific operation steps of the two most common modes.

1, routing mode deployment practice

first configure the extranet port of the load balancing device with a public IP, and configure the internal network port with a private IP in the same section as the backend server to enable the routing and forwarding function of the device. Then create a virtual service on load balance, set the listening port and protocol type, such as HTTP port 80, HTTPS port 443. Then add the backend server node, configure the server's Internet Protocol Address and server level port, and set the load balance algorithm, such as polling, minimum number of connections, etc. Finally configure security policies to limit illegal IP access. After completion, conduct a traffic test to verify whether the request can be normally assigned to the backend server.

2, bridge mode deployment practice

first configure the two network ports of the load balancing device as the IP of the same network segment, connect the front-end network and the back-end server cluster network respectively, and turn on the bridge mode function. Then create a virtual service, bind the corresponding listening port, add the back-end server node and configure the health check rule to ensure that load balance can sense the server status in real time. Then configure the address conversion rule, so that the response traffic of the back-end server can be returned to the client side through load balance, and finally perform a full-link test to check whether the traffic forwarding is normal and whether the server status can be accurately detected.

3. How to optimize the configuration after load balance deployment?

complete the basic deployment of load balance, targeted configuration optimization can further improve its operating efficiency and better adapt to business needs.

1, optimized load balancing algorithm and session keeping

adjust the load balancing algorithm according to business characteristics, such as for CPU-intensive services, you can choose a weighted minimum load algorithm based on server CPU usage; for services with strong session correlation, such as e-commerce shopping cart, you need to open the session holding function, through Cookies, IP hashes, etc. to assign the same user's request to the same backend server to avoid session loss problems.

2, Optimize health check and timeout settings

refine the health check rules. In addition to basic port detection, HTTP request detection can also be configured to check whether the application service of the backend server responds normally. At the same time, adjust the timeout parameters, such as connection timeout and response timeout time, to avoid the loss of requests or resource waste caused by unreasonable timeout settings. For example, the timeout time can be appropriately extended in weak connection scenarios.

IV. Precautions for load balance deployment and maintenance

load balance is completed, the detailed control of daily operation and maintenance is the key to ensuring its long-term stable operation.

1, establish real-time monitoring and alarm mechanism

need to build a load balance monitoring system to monitor the core indicators such as CPU usage, memory occupation, number of connections, traffic throughput of the equipment in real time, and monitor the health status of the backend server at the same time. Configure alarm rules. When the indicators exceed the threshold or the server is abnormal, notify the operation and maintenance personnel in time through emails, text messages, etc., so as to quickly troubleshoot the problem.

2, do a good job of configuration backup and disaster recovery plan

regularly backup the configuration file of load balance to avoid configuration loss due to equipment failure and misoperation. At the same time, it is necessary to build a load balance disaster recovery architecture, such as using the main and standby mode. When the main device fails, the standby device can automatically switch over the flow to ensure that the business is not interrupted. In addition, disaster recovery drills should be carried out regularly to verify the reliability of the switching process.

To sum up, the deployment of load balance is a systematic project. From the pre-demand sorting, environmental preparation, to the selection of deployment mode, configuration optimization, and then to the later operation and maintenance control, each link needs to be precisely controlled. By following the standardized practical steps and implementing various precautions, load balance can effectively play the role of traffic scheduling, build a high-availability and high-performance operation base for the business system, and help the stable development of the business.