hashring

What it is and what it does

Hashring provides a consistent hashing implementation for Python, using md5 as its underlying hash function. It solves the problem of distributing keys across a set of nodes (such as cache servers or database shards) in a way that minimizes the number of keys that need to be remapped when the set of nodes changes. This is particularly useful in distributed systems where you want stable key-to-node assignments despite node additions or removals.

The package has no external runtime dependencies and installs as a pure Python wheel, making it lightweight to add to any project. However, it is no longer actively maintained—the last commit was in November 2021 and the most recent release dates to April 2015. While it is classified as Production/Stable, you should be aware that bugs or compatibility issues with modern Python versions will not receive fixes.

Use it for:

• Distributing cache keys across multiple Memcached or Redis nodes with minimal key remapping on node failure or addition.
• Assigning database shard keys in a distributed database cluster to balance load while maintaining consistent routing.
• Load-balancing requests to backend servers in a way that keeps related requests routed to the same server.
• Partitioning data across multiple storage nodes in a distributed system while minimizing data movement on topology changes.

Worth the install?

AI-flagged interpretation of the facts on this page — verify before relying

Implements consistent hashing in Python using md5 as the hashing function, enabling distributed systems to map keys to nodes in a way that minimizes remapping when nodes are added or removed.

Yes, if you need consistent hashing and are comfortable with an unmaintained library. The code is simple and stable, with no known vulnerabilities and low install friction. However, verify that md5 hashing meets your security and collision-tolerance requirements, and test compatibility with your target Python version—the package's classifiers only list support up to Python 3.4, and there is no active maintenance to address issues with newer versions.

Install

hashring on PyPI

pip install hashring

uv add hashring

poetry add hashring

Installing hashring

Before you install

Installation is straightforward with no runtime dependencies. However, the package is abandoned—last commit was 2021-11-14 and no releases since 2015-04-14. It remains marked Production/Stable but receives no maintenance.

License in practice

BSD license is permissive, allowing commercial and private use with minimal restrictions, making it safe from a licensing standpoint for most projects.

Quickstart

pip install hashring

from hashring import HashRing

hr = HashRing(nodes=['node1', 'node2', 'node3'])
node = hr.get_node('some_key')

Verify before relying

• Whether md5 hashing is cryptographically sufficient for your use case (md5 is not collision-resistant)
• Compatibility with Python versions beyond 3.4 (classifiers list only up to 3.4)
• Whether the implementation handles virtual nodes or other advanced consistent hashing features

Package facts

Evidence: hashring-1.5.1-py2.py3-none-any.whl

Tags

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