Client & Connections¶

To connect to a Riak cluster, you must create a RiakClient object. The default configuration connects to a single Riak node on localhost with the default ports. The below instantiation statements are all equivalent:

from riak import RiakClient, RiakNode

RiakClient()
RiakClient(protocol='http', host='127.0.0.1', http_port=8098)
RiakClient(nodes=[{'host':'127.0.0.1','http_port':8098}])
RiakClient(protocol='http', nodes=[RiakNode()])

Note

Connections are not established until you attempt to perform an operation. If the host or port are incorrect, you will not get an error raised immediately.

The client maintains a connection pool behind the scenes, one for each protocol. Connections are opened as-needed; a random node is selected when a new connection is requested.

Client objects¶

Nodes¶

The nodes attribute of RiakClient objects is a list of RiakNode objects. If you include multiple host specifications in the RiakClient constructor, they will be turned into this type.

Retry logic¶

Some operations that fail because of network errors or Riak node failure may be safely retried on another node, and the client will do so automatically. The items below can be used to configure this behavior.

Client-level Operations¶

Some operations are not scoped by buckets or bucket types and can be performed on the client directly:

Accessing Bucket Types and Buckets¶

Most client operations are on bucket type objects, the bucket objects they contain or keys within those buckets. Use the bucket_type or bucket methods for creating bucket types and buckets that will proxy operations to the called client.

Bucket Type Operations¶

Bucket Operations¶

Key-level Operations¶

Timeseries Operations¶

Query Operations¶

Search Maintenance Operations¶

Serialization¶

The client supports automatic transformation of Riak responses into Python types if encoders and decoders are registered for the media-types. Supported by default are application/json and text/plain.

Deprecated Features¶

Full-text search¶

The original version of Riak Search has been replaced by Riak Search 2.0 (Yokozuna), which is full-blown Solr integration with Riak.

If Riak Search 1.0 is enabled, you can query an index via the bucket’s search() method:

bucket.enable_search()
bucket.new("one", data={'value':'one'},
           content_type="application/json").store()

bucket.search('value=one')

To manually add and remove documents from an index (without an associated key), use the RiakClient fulltext_add() and fulltext_delete() methods directly.

Legacy Counters¶

The first Data Type introduced in Riak 1.4 were counters. These pre-date Bucket Types and the current implementation. Rather than returning objects, the counter operations act directly on the value of the counter. Legacy counters are deprecated as of Riak 2.0. Please use Counter instead.

Warning

Legacy counters are incompatible with Bucket Types.