Object Storage Service (OSS) is a secure, cost-effective, and highly durable cloud storage service provided by Alibaba Cloud. OSS delivers at least 99.9999999999% (twelve 9's) data durability and 99.995% availability, with platform-independent RESTful APIs that let you store and access any type of data anytime, anywhere.
| Standard | High-durability, high-availability storage for frequently accessed data. Ideal for social media images, audio/video applications, large websites, and big data analytics. |
| Infrequent Access (IA) | Lower-cost storage for data accessed once or twice a month. Suitable for long-term backup of mobile apps, smart devices, and enterprise data. Supports real-time access. |
| Archive | Low-cost storage for data retained at least six months with infrequent access. Restoration takes up to one minute before reading. Suitable for archival data, medical images, scientific materials, and video footage. |
| Cold Archive | Lowest-cost storage for data retained over extremely long periods. Examples: compliance-mandated archives, accumulated big data and AI raw data, film and television media resources, and online education video archives. |
Scenarios
- Storage and distribution of audio, video, and static website data
Each object has a unique HTTP URL for distribution. OSS buckets can serve as origins for Alibaba Cloud CDN. With no storage partitioning, OSS handles data-intensive sites such as image and video sharing platforms. Devices, websites, and mobile apps can read from and write to OSS directly via file upload or streams.
- Static website hosting
OSS provides cost-efficient, highly available storage for static HTML files, images, videos, and client-side scripts.
- Data warehouse for computing and analysis
OSS scales to serve multiple computing nodes simultaneously, eliminating single-node performance bottlenecks.
- Data backup and archiving
OSS provides highly available, scalable, and secure backup and archiving. Lifecycle rules automatically transition cold data to IA or Archive to reduce costs. Cross-region replication (CRR) rules replicate data between buckets in different regions asynchronously in near real-time.
Performance
For optimal performance, place your ECS instance in the same region as the bucket. Server-side latency is negligible compared to network latency. OSS scales with storage capacity, requests, and users — with multiple threads or clients accessing simultaneously, total throughput far exceeds what a single server can deliver.
Multipart upload accelerates uploads for objects larger than 5 GB by splitting them into parts uploaded separately. OSS combines completed parts into a single object, enabling resumable upload — if a part fails, you re-upload only that part, not the entire object.
Many developers pair OSS with search engines (OpenSearch) or databases (Tablestore, RDS for MySQL) — storing object data in OSS and metadata (names, sizes, keywords) in the database for indexed queries.
OSS transfer acceleration speeds up remote uploads and downloads of large objects through smart scheduling, protocol stack tuning, optimal route selection, and transfer algorithm optimization.
Alibaba Cloud CDN accelerates downloads of frequently accessed static objects by distributing content from OSS bucket origins to edge nodes, routing requests to the optimal node to reduce latency and congestion.
Data durability and service availability
OSS distributes data across three zones within a region. If one zone becomes unavailable, data remains accessible — delivering 99.9999999999% (twelve 9's) durability and 99.995% availability.
Enabling CRR replicates data to a bucket in another region asynchronously in near real-time. Both source and destination buckets provide 99.9999999999% (twelve 9's) durability and 99.995% availability.
Scalability and elasticity
Unlike traditional file systems with directory limits, OSS imposes no cap on total storage or per-bucket capacity. You can store unlimited objects in a bucket. OSS distributes data copies across servers in the same region, all backed by Alibaba Cloud high-performance infrastructure.
Security
OSS security features include server-side encryption, client-side encryption, Referer-based hotlink protection, fine-grained access control, log audit, and WORM retention policies. OSS is the only cloud service in China that meets Cohasset Associates audit and certification requirements for electronic data storage. Buckets with retention policies support compliance with SEC Rule 17a-4(f), CFTC Rule 1.31(c)-(d), and FINRA Rule 4511(c). Overview.
Operations
OSS provides standard RESTful API operations. Objects are stored in globally unique buckets, each identified by a unique key. OSS has no folder hierarchy — all elements are objects. You can simulate folders by creating objects with keys ending in a forward slash (/), such as folder1/folder2/file.
OSS provides SDKs for 10+ languages including Java, Python, PHP, Go, Android, and iOS. ossutil is a high-performance CLI with commands such as ls, cp, cat, and config for managing buckets and objects, supporting concurrent uploads on Windows, Linux, and macOS. The graphical tool ossbrowser handles browsing, uploading, and downloading objects and folders. The OSS console provides web-based resource management.
Event notifications alert you to operations on your OSS resources. For more information, see Process real-time OSS object changes with event notifications.
Billing
OSS fees include storage, traffic, API calls, and data processing. Billing is pay-as-you-go: fees within an hour are billed the next hour using the formula Fees = Actual usage × Unit price. Subscription resource plans are available for some billing items to reduce costs. Billing items and methods.