twitter / distributedlog

A high performance replicated log service. (The development is moved to Apache Incubator)

Version Matrix


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Apache DistributedLog (incubating)

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.


The Apache DistributedLog project is in the process of incubating. This includes the creation of project resources, the refactoring of the initial code submissions, and the formulation of project documentation, planning and the improvements of existing user and operation documents. Any feedback and contributions are welcome.


High Performance

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 or Yarn. The service layer is able to support large scale writes (fan-in) and reads (fan-out).

Various Workloads

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.

Multi Tenant

To support a large number of logs for multi-tenants, DL is designed for I/O isolation in real-world workloads.

Layered Architecture

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.

First Steps

Next Steps

Get In Touch

Report a Bug

For filing bugs, suggesting improvements, or requesting new features, help us out by opening a jira.

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Subscribe or mail the list - Ask questions, find answers, join developement discussions and also help other users.


We feel that a welcoming open community is important and welcome contributions.

Contributing Code

  1. See Developer Guide to get your local environment setup.

  2. Take a look at our open issues.

  3. Review our coding style and follow our code reviews to learn about our conventions.

  4. Make your changes according to our code review workflow.

  5. Checkout the list of project ideas to contribute more features or improvements.

Improving Website and Documentation

  1. See website/ on how to build the website.

  2. See docs/ on how to build the documentation.


Apache DistributedLog is an open source project of The Apache Software Foundation (ASF). The Apache DistributedLog project originated from Twitter.