Optimization problems are found everywhere at Alibaba, from e-commerce and logistics to cloud computing and machine learning. Some key optimization challenges at Alibaba include predicting user needs, effectively matching users with products, online advertising matching users with ads, scheduling jobs on computing resources, and warehouse and transportation management in logistics. The speaker's team focuses on developing optimization techniques to solve large-scale, non-convex problems for applications across Alibaba's various business units.

2. Optimization at Alibaba
Zhenliang Zhang
iDST at Alibaba

3. Alibaba Ecosystem
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4. Optimization Problems Found Everywhere
Data Center
Optimization
Resource
Optimization
Large-scale
Nonconvex
Optimization
E-commerce Logistics Smart City Digital Entertainment
Computing
Infrastructure
Computing
Platform
Machine Learning
Platform
Business

5. E-commerce
• Connecting consumers with sellers/products
– Efficiency is the key of any e-commerce platform
– Alibaba: 0.5 Bn users, 1 Bn products, GMV 459Bn
• Two key problems
– Prediction: accurately predict users' needs
– Matching: effectively match users' needs with products

6. Predicting User Needs
Trans.
Behavior
LBS
User Profiles
Real-time data Contextual data
Prediction

7. Effectively Matching User Needs
Ease case: supplies ³ demands
• A simple greedy matching works best
• Match each user with the best prediction

8. Difficult case: supplies < demands
• How to decide which users will get which items ?
• Greedy algorithm does not work, leading to assignment problem
Effectively Matching User Needs

9. Assignment Problem
• Given a bipartite graph
– m agents & n tasks
– An award ci,j is given when agent i is
assigned to perform task j
• Optimal task assignment
– Goal: maximize overall awards
– Constraints: each agent/task can be
assigned to a limited number of
tasks/agents
0.8
0.1
ci,j

10. Applications in Alibaba
• Online advertisement
– Match users with different ads
– Awards: the number of clicks
– Constraints: budgeted number of
impressions for individual ads
• Significance of optimization
– Improved revenue by ~50 m RMB per
day
Users Ads

11. Ask-All ( LM)
Background
• Allow customers to raise questions about products
before making purchases
• System distributes questions to users who could
provide answers within an hour
Goal
• Maximize the number of questions answered
Constraints
• For better experience, each user will only be asked
for a small number of questions QuestionsUsers

12. Example of Ask-All

13. • Mobile message push
• Online traffic allocation
• Online distribution of coupons
• Stock aware online recommendation
• Online assignment of delivery requests
• …
Other Applications in Alibaba

14. Cloud Computing
• The largest cloud computing company in China
– 1Million users, ~100% YoY revenue growth
• Need to improve resource management
– Reliability: service-level agreement
– Pricing & cost reduction

15. Computing Infrastructure at Alibaba
• 6 data centers in mainland China
• 8 data centers globally, 3 more are coming
• Power management
– US data centers consumed ~70
billion kilowatt-hours of electricity
• Network planning
– Minimize the latency

16. Example: Scheduling Problem
• Online multi-resource allocation problem, e.g. CPU, Mem, Disk
• Generally NP hard
• Need to make online decision
Compute
Resources
Scheduler Pending Jobs

17. Example: Traffic Balancing
• Assign projects to clusters with minimal cost
– Dependent projects need to communicate,
– But traffic between clusters are expensive
• Constraints
– Network band restriction
– Some project migration are infeasible

18. Logistics in Alibaba
• Cainiao network
– 80 major warehouse networks, 4000 Cainiao partners
– 0.5 Bn parcels/day, next day delivery service in 150 cities
• Key areas
Supply chain Warehouse
management
Transportation
management

19. Applications of Optimization in Logistics
• 3D bin packing
– Find smallest number of boxes to
include all items from an order
• Warehouse management
– New retailer Hema
• Vehicle route planning
– Planning for order pickup
– Planning for delivery service

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Focus of Our Team

21. Optimization at Alibaba
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