Reveal the Technical Hard Power behind the Live Broadcast of CCTV Spring Festival Gala (2)

QPS request with high code rate and high concurrency provides a complete set of capability service system

With the rapid development of Internet technology, the capacity of mobile devices is improving, the number of users is increasing, and the activity mode is becoming more and more novel. High code rate, high concurrency and high QPS have gradually become the basic capability requirements of cloud service enterprises. In the live broadcast of CCTV Spring Festival Gala, 5G super-definition and VR live broadcast form was innovatively used. A total of 1 billion video views on the whole network and the red envelope snatching interaction of QPS with high concurrency (number of user requests per second) posed a huge challenge to the service capacity of Kingsoft Cloud.

In order to more effectively guarantee the transmission stability of super-definition video and VR video in peak hours, the technology team of Kingsoft Cloud and cctv.cn re-optimized the system architecture together; realized all-round linkage in technology, management, operation and other dimensions through resource connection; and ensured the smooth progress of the activity to the greatest extent.

At present, Kingsoft Cloud has more than 1,000 CDN nodes in China, and the bandwidth reserve of the whole network has reached 100Tbps, which can guarantee the rapid and stable distribution of the content of CCTV Spring Festival Gala to the greatest extent. In addition, CDN products of Kingsoft Cloud are based on a supersized distributed cluster. With massive concurrent capacity, they can provide stable, smooth and rich network acceleration services. At the same time, the holographic transparent data support system of Kingsoft Cloud can realize a full range of highly available service guarantees, and provide customers with elastic and transparent CDN services with low latency.

For high-definition video, VR and other video applications, the distribution nodes of video cloud of Kingsoft Cloud have a special high-capacity design. At the level of system architecture, it adopts Dorado, the new generation of Cache architecture. The application of multi-level cache technology, multithreading and other technologies improves the concurrency performance and stability by more than 50%. At the level of hardware device, it adopts the third generation of DMA technology (SSD+MemCache+AIO), and specially optimizes compiler, storage and network at the same time, improving the I/O performance by 400%. At the level of transmission protocol, the transmission efficiency of TCP network of Kingsoft Cloud is improved by 30% after kernel optimization.

In order to further reduce the occupation of bandwidth, in the process of this live broadcast guarantee, Kingsoft Cloud provided complete CDN product matrix, including live broadcast, VOD, download and small documents, as well as all-round technical services, including edge computing, smart HD, P2P, QUIC bilateral acceleration and other technical systems.

Among them, smart HD integrates with a variety of technologies, reduces the volume of encoded video, and saves 20%-40% of video transmission bandwidth. With KSC265 transcoding technology, it can reduce the video transmission bandwidth for the second time. Kingsoft Cloud provides AI+ AV1 intelligent cloud transcoding service. With a compression rate of 80.57%, it is leading in the industry.

At the level of edge computing, in the big data upload and API acceleration scenarios, the file upload speed of Kingsoft Cloud edge computing has increased by 40%, the upload success rate has increased to 99.5%, and the success rate of API service query request has increased to 99.9%. In the scenario of live broadcast in the same city, the relatives and friends in the same city are allowed to pull the traffic and watch nearby, greatly saving the backbone network bandwidth and improving the watching quality.

In addition to basic means such as smart HD, selection of the best traffic inlet and protocol optimization, Kingsoft Cloud has also made corresponding technical reserves for super HD and VR live broadcast under the background of 5G. The low delay distribution scheme of CMAF not only solves the delay problem of HLS, DASH and other protocols, but also has the multi-code rate adaptive function. Combined with the alignment transcoding technology, it can provide the multi-code rate adaptive output of 8K, 4K, 1,080P or even lower at the same time, so that in different network conditions terminal users can watch HF or smooth program at the same time.

Therefore, with a full set of technical service system and resource reserve capacity provided by Kingsoft Cloud, including video cloud and CDN, Kingsoft Cloud has experienced the peak impact of high traffic of HD video and peak traffic of many times of red envelope snatching.


The customer success guarantee platform provides a full range of guarantee capabilities

In addition to the optimization of the underlying technologies, Kingsoft Cloud innovatively developed the "customer success guarantee platform" to ensure the success of the live broadcast of CCTV Spring Festival Gala, which played an important role in the live broadcast guarantee of CCTV Spring Festival Gala and achieved twice the result with half the effort.

"The customer success guarantee platform" is not strange in the industry. At the "2019 Gold Medal Operation and Maintenance Conference" held on December 26th, 2019, the "customer success guarantee platform" of Kingsoft Cloud was rated as the "Annual Excellent Case of the Operation and Maintenance Industry in 2019".

As we all know, the public cloud provides convenience for the flexibility of customer resources. However, at the same time, it brings difficulties to the operation and maintenance personnel of public cloud, such as the lack of technical means to see problems from the perspective of customers, the lack of effective initiative guarantee means and the lack of global real-time cognition of customer product experience. In order to help public cloud customers to succeed in their business and achieve win-win business results, Kingsoft Cloud launched the "customer success guarantee platform" to provide a full range of guarantee capabilities.

Among them, the "live broadcast guarantee robot" developed by Kingsoft Cloud can automatically create a special guarantee communication group according to the live broadcast guarantee needs, and communicate about problems during the live broadcast guarantee of customer in the group to avoid information fragmentation; the "live broadcast guarantee robot" monitors the resource stability of customer according to the needs, adds "all-round monitoring", creates the corresponding "customer resource monitoring screen", sets the "sensitive alarm threshold", and ensures that the customer can know the problem in one step; and in addition, the "live broadcast guarantee robot" sends the alarm and work order to the handler, and supervises the handler to complete the processing within a certain period of time, which greatly improves the labor efficiency.

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In addition, in order to ensure the smooth progress of live broadcast guarantee of CCTV, Kingsoft Cloud established a special team consisting of nearly 50 people to provide the remote and on-site guarantee across product, R&D, operation, customer service and risk control teams for 24 hours a day and 7 days a week. It provided on-site technical services, arranged the on-site guarantee of application and network operation and maintenance, realized the second-level response and emergency treatment, and solved any problem immediately. In addition, in addition to the regular operation team, Kingsoft Cloud specially arranged an emergency team to take additional measures for emergencies. The two teams operated independently in case of temporary emergencies to ensure the smooth progress of live broadcast guarantee.

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(Picture: Spring Festival Guarantee Command Center of Kingsoft Cloud in 2020)

In the special period when all the people prevented the spread of virus and when we watched the Spring Festival Gala and laughed at home, every live broadcast guarantee programmer of Kingsoft Cloud actively took health precautions, took temperature when entering the building, wore masks, and contributed to the smooth live broadcast of CCTV Spring Festival Gala in the 2020 Kingsoft Cloud Spring Festival Guarantee Command Center.

It cannot be denied that Kingsoft Cloud guaranteed the successful live broadcast of CCTV Spring Festival Gala, which proved the high technical strength of Kingsoft Cloud once again. In the future, with the arrival of the era of 5G super HD and VR, Kingsoft Cloud will provide more comprehensive technology and service capabilities, and guarantee the live broadcast of more major events and competitions.