Community Blog Apsara Luoshen: The Web Engine behind Alibaba's Double 11 Shopping Festival

Apsara Luoshen: The Web Engine behind Alibaba's Double 11 Shopping Festival

As one of the Alibaba Cloud Apsara systems, Luoshen is responsible for on-cloud virtual networks and is also the infrastructure behind over 100 Alibaba Cloud products.

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Many shoppers may remember the 2018 Alibaba Double 11 Shopping Festival that took shattered records by exceeding $30.8 billion in gross merchandise value (GMV) in just 24 hours. Particularly, around midnight, hundreds of millions of online shoppers simultaneously went to their online shopping carts, eagerly searching for coupons and red envelopes from shops on Alibaba's e-commerce platform, placing their orders and then making payments. Based on my personal shopping experience during this event, which was smooth and pleasant, Alibaba managed to promptly address the explosive growth of online shopping needs. It is safe to say that there are no other scenarios on Earth that can create as much Internet traffic as this event did.

The network infrastructure is definitely the most important aspect behind this Double 11 event. The network provided by Alibaba Cloud has safeguarded Alibaba Double 11 events for eight consecutive years and has been supporting most businesses belonging to Alibaba Group and Ant Group. Which network products provided support for this Double 11 event? What kind of technical support is behind this event? Let me fill everyone in. First, let's take a look at the network products that provided support for this Double 11 event.


Alibaba Cloud's Suite of Network Products for Double 11

Server Load Balancer (SLB)

Sever Load Balancer acts as a traffic manager to easily schedule and distribute network traffic during peak hours. While you enjoy your Taobao or Tmall shopping spree, SLB is the first network product that provides you with services. SLB sends your requests to the back-end server for processing and then returns the results. SLB allows hundreds of millions of requests to be sent to the back-end server where they are processed, ensuring a smooth shopping experience.

To prepare for the Double 11 event, Alibaba Cloud set up ultra-large SLB clusters that can support 17 million new connections and 3.4 billion concurrent connections. Although the public network traffic on the SLB during the peak hours had doubled and the number of connections was seven times more than last year, there weren't any network problems throughout this year's Double 11 event.

Theoretically speaking, SLB can support half of the Earth's population shopping online at the same time!

NAT Gateway

When you add the goods you want to buy to the shopping cart and begin the payment process, our NAT Gateway begins to play its part. Do you recall redirecting from the order page to Alipay in Tmall and Taobao? The invocation of each payment request to the Alipay interface is made through the NAT gateway to implement payment. The stability of the NAT gateway ensures that each payment is processed smoothly.

Because the NAT gateway can support 3 million connections on a single instance, it can efficiently deal with the transaction peak up to 491,000 transactions per second during peak hours.

Perhaps the only disadvantage of the ultra-smooth and fast payment process is that you don't have time to reconsider purchases.

Express Connect

Express Connect is a high-speed access point leading to Alibaba Cloud. Complicated hybrid systems and the collaboration of data centers across multiple regions are needed to support events like the Double 11 event. Express Connect connects the services running on these data centers. Based on Alibaba Cloud Backbone Network, Express Connect seamlessly connects physically separated infrastructure to form an organic whole, allowing these centers to work together in providing support for the Double 11 event.

To safeguard the instance of this Double 11 event, Alibaba Cloud set up the largest hybrid cloud network ever to support fast scheduling and distribution of adequate public cloud resources when transactions increased sharply.

With Express Connect, downtime is no longer a concern. Shop owners can go ahead and send out another wave of red envelopes to their customers.

Virtual Private Cloud (VPC)

VPC is simply a user's private space on the cloud. Because Alibaba Cloud is a shared multi-tenant space on the cloud, VPC is essential to the security of all e-commerce information stored on the cloud. VPC is a logically (completely) independent network space on Alibaba Cloud's sharing platform partitioned exclusively for e-commerce users. All e-commerce data is stored in this space to ensure information and transaction security.

With VPC, sales and purchases are secure and assured.

Apsara Luoshen – Powerful Virtual Network System

Behind all these cloud products is the powerful virtual network technology - Apsara Luoshen. Luoshen is an important part of Alibaba Cloud's network technologies. Let's take a look at Alibaba Cloud's network technologies on whole:

  1. On-cloud network (Luoshen): provides many networking features for Alibaba Cloud and manages outbound and inbound public network traffic. Among these features are load balancing, elastic network IPs, and NAT.
  2. Cloud-to-cloud network (Zhinv): responsible for network connections among VPCs; enables establishing a large network across all 19 Alibaba Cloud regions in just one minute.
  3. Migration-to-cloud network (Change): As users' secure channel to the cloud, it connects PoPs around the world to the VPC channel on the cloud to enable intercommunication among PoPs.
  4. Intelligent network (Qitian): monitors and issues alerts on the on-cloud network, cloud-to-cloud network, and migration-to-cloud network in real time; avoids faults and simplifies maintenance; performs big data analysis to predict network trends and provide users with suggestions.


As one of the Alibaba Cloud Apsara systems, Luoshen is responsible for on-cloud virtual networks. In addition to providing network products such as VPC and SLB, it is also the infrastructure behind over 100 cloud products including ECS, RDS, OSS, and NAS. It also supports various business scopes under Alibaba Group and Ant Financial Group, such as e-commerce, payment, and logistics. Luoshen has over 1 million global users across various industries.

Luoshen's key features include large scale, high performance, and high reliability. Capable of performing second-level forwarding, Luoshen can implement network elasticity from 1 MB to 1 TB in only one second. Luoshen's single network supports 100,000 computing nodes. With this large scale and excellent performance, it can easily deal with the massive peak flow at midnight during the Double 11 Shopping Carnival. As for the reliability, the multi-datacenter disaster tolerance architecture is key. As for the mean time between failures (MTBF), the failure time for a single Luoshen instance is as short as 50ms.

In addition to Double 11 events, Luoshen has also provided support for large-traffic and high-concurrency scenarios such as the World Cup, Spring Festival galas and the Spring Festival travel rush. I will keep you up to date with advances in Luoshen and other Alibaba Cloud technologies.

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Raja_KT March 19, 2019 at 3:57 pm

Whaw...." In addition to providing network products such as VPC and SLB, it is also the infrastructure behind over 100 cloud products including ECS, RDS, OSS, and NAS"---the SDN ...