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Redis sharding api

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Redis Shard

A redis sharding api. Sharding is done based on the CRC32 checksum of a key or key tag ("key{key_tag}"), according to this article .

The source code is locate at github .

Build Status


Creating a hash ring with multiple servers,By default the hash ring uses a crc32 hashing algorithm on the server's name config.You can define the name anything as you like,but it must be unique.

I don't want to bind the hashring with ipaddress,because if I do some master/slave switches, I can only change the ipaddress related config. The name is kept,so the hashring's order is kept.

>>> from redis_shard.shard import RedisShardAPI
>>> servers = [
    ...    {'name':'server1','host':'','port':10000,'db':0},
    ...    {'name':'server2','host':'','port':11000,'db':0},
    ...    {'name':'server3','host':'','port':12000,'db':0},
    ...    {'name':'','host':'','port':13000,'db':0},
    ...    ]
>>> client = RedisShardAPI(servers)
>>> client.set('test',1)
>>> print client.get('test')
>>> client.zadd('testset','first',1)
>>> client.zadd('testset','second',2)
>>> print client.zrange('testset',0,-1)

Hash tags

see article for detail.

>>> client.set('foo',2)
>>> client.set('a{foo}',5)
>>> client.set('b{foo}',5)
>>> client.set('{foo}d',5)
>>> client.set('d{foo}e',5)
>>> print client.get_server_name('foo') == client.get_server_name('a{foo}') == client.get_server_name('{foo}d') \
... == client.get_server_name('d{foo}e')

I also added an tag_keys method,which is more quickly than default keys method,because it only look one machine.

>>> client.tag_keys('*{foo}*') == client.keys('*{foo}*')

Config Format

There's three config formats

  • list:
servers = [
{'name':'node1','host':'','port':10000,'db':0}, {'name':'node2','host':'','port':11000,'db':0}, {'name':'node3','host':'','port':12000,'db':0}, ]
  • dict:
servers =
{ 'node1': {'host':'','port':10000,'db':0},
'node2': {'host':'','port':11000,'db':0}, 'node3': {'host':'','port':12000,'db':0},


  • url_schema:

    servers = ['redis://',

    'redis://', 'redis://'


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