pymemcache 1.3.5

A comprehensive, fast, pure Python memcached client

pymemcache

A comprehensive, fast, pure-Python memcached client.

pymemcache supports the following features:

• Complete implementation of the memcached text protocol.

• Configurable timeouts for socket connect and send/recv calls.

• Access to the “noreply” flag, which can significantly increase the speed of writes.

• Flexible, simple approach to serialization and deserialization.

• The (optional) ability to treat network and memcached errors as cache misses.

Installing pymemcache

Install from pip:

pip install pymemcache

For development, clone from github and run the tests with:

git clone https://github.com/pinterest/pymemcache.git
cd pymemcache
python setup.py nosetests

Usage

See the documentation here: http://pymemcache.readthedocs.org/en/latest/

Comparison with Other Libraries

pylibmc

The pylibmc library is a wrapper around libmemcached, implemented in C. It is fast, implements consistent hashing, the full memcached protocol and timeouts. It does not provide access to the “noreply” flag, and it doesn’t provide a built-in API for serialization and deserialization. It also isn’t pure Python, so using it with libraries like gevent is out of the question.

Python-memcache

The python-memcache library implements the entire memcached text protocol, has a single timeout for all socket calls and has a flexible approach to serialization and deserialization. It is also written entirely in Python, so it works well with libraries like gevent. However, it is tied to using thread locals, doesn’t implement “noreply”, can’t treat errors as cache misses and is slower than both pylibmc and pymemcache. It is also tied to a specific method for handling clusters of memcached servers.

memcache_client

The team at mixpanel put together a pure Python memcached client as well. It has more fine grained support for socket timeouts, only connects to a single host. However, it doesn’t support most of the memcached API (just get, set, delete and stats), doesn’t support “noreply”, has no serialization or deserialization support and can’t treat errors as cache misses.

External Links

The memcached text protocol reference page:

https://github.com/memcached/memcached/blob/master/doc/protocol.txt

The python-memcached library (another pure-Python library):

https://github.com/linsomniac/python-memcached

Mixpanel’s Blog post about their memcached client for Python:

http://code.mixpanel.com/2012/07/16/we-went-down-so-we-wrote-a-better-pure-python-memcache-client/

Mixpanel’s pure Python memcached client:

https://github.com/mixpanel/memcache_client

Credits

• Charles Gordon

• Dave Dash

• Dan Crosta

• Julian Berman

• Mark Shirley

• Tim Bart

• Thomas Orozco

• Marc Abramowitz

• Marc-Andre Courtois

• Julien Danjou

• INADA Naoki

• James Socol

• Joshua Harlow

• John Anderson

• Adam Chainz

• Ernest W. Durbin III

• Remco van Oosterhout

Change Log

New in version 1.3.5

• Bug fix for HashClient when retries is set to zero.

• Adding the VERSION command to the clients.

New in version 1.3.4

• Bug fix for the HashClient that corrects behavior when there are no working servers.

New in version 1.3.3

• Adding caching to the Travis build.

• A bug fix for pluggable hashing in HashClient.

• Adding a default_noreply argument to the Client ctor.

New in version 1.3.2

• Making the location of Memcache Exceptions backwards compatible.

New in version 1.3.0

• Python 3 Support

• Introduced HashClient that uses consistent hasing for allocating keys across many memcached nodes. It also can detect servers going down and rebalance keys across the available nodes.

• Retry sock.recv() when it raises EINTR

New in version 1.2.9

• Introduced PooledClient a thread-safe pool of clients