Apache DistributedLog (DL) is a high-throughput, low-latency replicated log service, offering durability, replication and strong consistency as essentials for building reliable real-time applications.
DL is able to provide milliseconds latency on durable writes with a large number of concurrent logs, and handle high volume reads and writes per second from thousands of clients.
Durable and Consistent
Messages are persisted on disk and replicated to store multiple copies to prevent data loss. They are guaranteed to be consistent among writers and readers in terms of strict ordering.
Efficient Fan-in and Fan-out
DL provides an efficient service layer that is optimized for running in a multi- tenant datacenter environment such as Mesos orYarn. The service layer is able to support large scale writes (fan-in) and reads (fan-out).
DL supports various workloads from latency-sensitive online transaction processing (OLTP) applications (e.g. WAL for distributed database and in-memory replicated state machines), real-time stream ingestion and computing, to analytical processing.
To support a large number of logs for multi-tenants, DL is designed for I/O isolation in real-world workloads.
DL has a modern layered architecture design, which separates the stateless service tier from the stateful storage tier. To support large scale writes (fan- in) and reads (fan-out), DL allows scaling storage independent of scaling CPU and memory.