Introduction: Recently, the first live broadcast of Alibaba Cloud "Run Fast 2021" was launched online. The live broadcast focused on the best practices of the CDN industry. It not only explained the best practice map of Alibaba Cloud CDN products released on the entire network in detail, but also discussed how CDN products and customer scenarios can be more efficiently matched to form an optimal solution. Sharing, hope that based on the sharing of Alibaba and the experience of successful customers, it will speed up the digital upgrade of customers in 2021. This article is organized from the first live broadcast topic "Comprehensive Analysis of CDN Industry Best Practices". In the actual application scenarios of customers, it introduces the core technical function modules of CDN and the best practices of large-scale events accumulated for many years.
Recently, the first live broadcast of Alibaba Cloud's "Run Fast 2021" was launched online. The live broadcast focused on the best practices of the CDN industry. It not only explained the best practice map of Alibaba Cloud CDN products released on the entire network in detail, but also discussed how CDN products and customer scenarios can be more efficiently matched to form an optimal solution. Sharing, hope that based on the sharing of Alibaba and the experience of successful customers, it will speed up the digital upgrade of customers in 2021. This article is organized from the first live broadcast topic "Comprehensive Analysis of CDN Industry Best Practices". In the actual application scenarios of customers, it introduces the core technical function modules of CDN and the best practices of large-scale events accumulated for many years.
Sharing guest: Luo Xiaofei, Alibaba Cloud CDN product architect, has 12 years of experience in the CDN industry. He has rich experience in various modules such as solutions, pre-sales, products, and technical support in the CDN field, and has been responsible for CDN service guarantees for many large-scale events and important projects. Currently participating in the design, evolution, and upgrade of Alibaba Cloud CDN technology architecture as a major technical role.
Complete CDN product best practice diagram
1. Full solution to the big picture
1. Globally recognized CDN
Alibaba Cloud is the first batch of companies to obtain CDN licenses. It has passed multiple global and national certifications and is very safe and reliable in terms of services.
2. Convenient expansion
Alibaba Cloud CDN is a very convenient and easy to expand CDN platform. Within the Alibaba Cloud ecosystem, it can be fully integrated with ECS, OSS, SLB, cloud monitoring and other products and services. For example, through cloud monitoring, users can easily monitor changes in the use of CDN and quickly generate alarms; through CDN back to the OSS source site, the intermediate transmission link will be an integrated cloud optimization solution; for CDN back to the source OSS traffic also has some preferential charging strategies; at the same time, Alibaba Cloud CDN provides solutions for dynamic and static mixed page processing, non-standard transmission protocol solutions, one-key console self-service opening full-link IPv6 access and other capabilities to distribute large files On the one hand, through multi-level caching and technical optimization, 95% hit rate and millisecond response are achieved, effectively helping customers improve user access efficiency and reduce origin site bandwidth.
3. One-stop distribution
Alibaba Cloud CDN realizes one-stop distribution based on four core systems: global intelligent scheduling, self-developed business support, distributed deployment of multi-level cache architecture and intelligent link system. First, the global intelligent scheduling system, equivalent to the brain of the CDN, is responsible for scheduling all users' access to the appropriate nodes, shortening the caching time of local DNS by providing HTTPDNS solutions, and considering bandwidth, operators, regions, CPU computing power, etc. Multi-dimensional attributes to complete the rapid and flexible scheduling of massive access. Second, the self-developed business support system is mainly for customer configuration management, real-time log push, and intelligent and sensitive monitoring, ensuring the stability and health of the CDN platform operation, and can achieve industry-leading network-wide refresh capabilities in seconds. Third, the node caching system achieves the improvement of caching efficiency by merging back to the source, removing the parameter back to the source setting, and setting different caching time for different content; the fourth is the intelligent link system, in the CDN there will always be resources that need to be returned To the source station, this system mainly selects an optimal path for the user in the back-to-source link.
In addition to the four core systems, the Alibaba Cloud CDN platform also provides: content tamper-proof capability, through full-link HTTPS transmission encryption, and entire network content consistency verification to achieve content tamper-proof; low-latency live broadcast capability, based on Alibaba Cloud GRTN global real-time transmission network, when RTMP and FLV traditional live broadcast is delayed by about 3 seconds, low-latency live broadcast is realized based on WEBRTC, and the delay can be controlled within 1 second, which facilitates better interaction between anchors and viewers; content security management capabilities , Through the security protection, machine traffic management and content identification capabilities on the CDN edge nodes, the overall platform content security management is realized; the image processing capability provides functions such as image compression, cropping, and format conversion.
Through the four core systems and the above core capabilities, in many typical business scenarios, customers can better use CDN to meet business needs. For example: in the mobile APP update scenario, user visits are huge. Through the global intelligent scheduling of Alibaba Cloud CDN, flexible and fast user visits can be realized for mass visits; in the online education live broadcast scenario, based on the Alibaba Cloud low-latency live broadcast solution , Can greatly reduce the end-to-end delay; in the dynamic content acceleration scenario of social interaction, through the Alibaba Cloud CDN intelligent link system, the optimal path is selected to improve the acceleration efficiency when returning to the source; in the financial security access scenario, through Alibaba Cloud CDN's content security management and anti-tampering solutions realize the safe and reliable transmission of business content.
4. Diversified management
The Alibaba Cloud CDN platform can realize diversified management. Through API interface, SDK or edge scripting capabilities, diversified requirements can be quickly implemented, and flexible connection with customer systems can be realized. At the same time, there are very complete and professional practices in the Double 11 shopping carnival, strong interactive live broadcast, and large-scale global event live broadcast.
2. CDN best practices for guaranteeing major events
With the annual Double Eleven and the popularization of mobile Internet and video, CDN traffic has shown exponential growth. Up to now, Alibaba Cloud CDN has 2800+ edge nodes around the world, with a bandwidth reserve of 130Tbps, serving hundreds of thousands of customers around the world, and providing accelerated services for 1.5 million domain names. Alibaba Cloud CDN creates an edge ecological network that connects the world. During the evening peak period, it processes hundreds of millions of QPS user connection requests per second, and sends billions of customer configuration management instructions to all nodes in the entire network every day.
1. Systematic engineering combining organization and system
Because Alibaba Cloud CDN has done a lot of major event guarantees, including the New Year’s Eve party, Spring Festival Gala live broadcast, World Cup, Asian Games, League of Legends Global Finals, CBA Professional League, 2020 World Artificial Intelligence Conference, and Double 11 Cat Night Internet live broadcast of many important events. Therefore, precipitation has summarized a set of systematic major event guarantee procedures, which are mainly realized from six parts: needs assessment, plan preparation, demand delivery, exercise stress testing, network closure guarantee, and event escort.
Most of the work is actually in the preparatory stage, that is, the preparatory stage and the pre-war stage. Just like the iceberg model, the real activity is like the tip of the iceberg at sea level. The actual work behind the activity is below sea level. For the larger iceberg main body, a lot of preparation and planning can be done to ensure the best results.
2. Bandwidth, computing resources and full link monitoring
When guaranteeing major events, one of the most important key resources of CDN is bandwidth resources. Bandwidth resources will focus on core indicators such as service type, service coverage, service hit rate, service classification, and combine network quality, storage conditions, CPU capacity, and node geographic location to achieve optimal scheduling and realize the maximum capacity of the entire network. And the safest operation.
The second key resource is computing power. With more and more business forms, the dynamic access carried on the CDN platform will also become particularly important for computing needs. So how to schedule computing power? Alibaba Cloud CDN knows the CPU consumption of each node and the amount of concurrent requests for each business on each node. To calculate the CPU consumption of each business unit QPS, combined with the overall bandwidth and computing power, can we do a more comprehensive global load balance Scheduling strategy to ensure the smooth operation of activities.
At the same time, the ability to monitor major events is very important. Alibaba Cloud CDN provides a flexible real-time full-link monitoring system. In the process from regional user access to edge nodes, upper-layer nodes, and full links, each link Key indicators, such as packet loss rate, first byte, error rate, round-trip delay, and bandwidth, can all be displayed on a graph in minutes. At the same time, full link monitoring is also very flexible, and customers can set different thresholds for different indicators according to the business form. Therefore, in a large-scale event, assuming an abnormal access to a certain area occurs, through Alibaba Cloud CDN full-link monitoring, the abnormal situation and the number of specific abnormal indicators can be quickly located, and the problem can be solved more efficiently.
3. A guarantee plan that connects with the customer's business
Whether it is Alibaba Group ecology or cloud customers, when CDN undertakes major event guarantees, the team must have a very clear understanding of its business. The figure below shows that when a customer is guaranteeing a live broadcast event, the CDN needs to understand the customer’s situation from the customer’s signal source, direction, master/backup mechanism, and bottoming plan, and formulate the most reasonable and complete live broadcast guarantee plan accordingly. , Including the structure of the live broadcast, the preparation of domain-related resources, and data display.
4. HTTPDNS method to build a highly available architecture
Most business scheduling is based on DNS, but there are problems such as hijacking and caching time in DNS scheduling. For this reason, for the protection of major activities, Alibaba Cloud CDN provides a high-availability architecture of HTTPDNS to better achieve:
- Avoid DNS hijacking
- Control the retry logic on the client
- Httpdns+dns combined use
- Solve the ttl time problem of LDNS
- Combining different resource groupings of Alibaba Cloud CDN to create highly available services
5. Programmable CDN
In 2019, Alibaba Cloud CDN launched the EdgeScript function, which supports CDN programmable configuration. Writing EdgeScript can be directly applied to the Alibaba Cloud CDN system quickly and flexibly. Through EdgeScript, it can quickly support the customized business requirements of CDN, and solve the problems of long release cycle of customized requirements and unagile business changes.
The applicable scenarios for EdgeScript are as follows:
- Customized authentication logic
- Customized request header & response header control
- Customized rewriting & redirection
- Customized A/B Testing
- Customized cache control
- Customized speed limit
- Other customized services
These functions are very useful for major event protection. For example, when the customer business wants the overall bandwidth to reach 800G, and wants to limit the speed of each user's single link, the CDN platform is required for custom development, testing, and release in the traditional way, and the cycle is relatively long. Through the programmable CDN platform, customers can directly implement edge scripts, greatly improving deployment efficiency.
Follow-up Alibaba Cloud CDN will share more latest product capabilities, solutions and technical practices in the "Alibaba Cloud Edge Plus" public account. Welcome everyone to discuss together.
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