Cassandra + Astra DB online store

Description

The [Cassandra / Astra DB] online store provides support for materializing feature values into an Apache Cassandra / Astra DB database for online features.

The whole project is contained within a Cassandra keyspace
Each feature view is mapped one-to-one to a specific Cassandra table
This implementation inherits all strengths of Cassandra such as high availability, fault-tolerance, and data distribution

Getting started

In order to use this online store, you'll need to run pip install 'feast[cassandra]'. You can then get started with the command feast init REPO_NAME -t cassandra.

Example (Cassandra)

{% code title="feature_store.yaml" %}

yaml

project: my_feature_repo
registry: data/registry.db
provider: local
online_store:
    type: cassandra
    hosts:
        - 192.168.1.1
        - 192.168.1.2
        - 192.168.1.3
    keyspace: KeyspaceName
    port: 9042                                                              # optional
    username: user                                                          # optional
    password: secret                                                        # optional
    protocol_version: 5                                                     # optional
    load_balancing:                                                         # optional
        local_dc: 'datacenter1'                                             # optional
        load_balancing_policy: 'TokenAwarePolicy(DCAwareRoundRobinPolicy)'  # optional
    read_concurrency: 100                                                   # optional
    write_concurrency: 100                                                  # optional

{% endcode %}

Example (Cassandra — multi-DC)

Use datacenters instead of hosts when your cluster spans multiple datacenters. Each entry gets a named Cassandra execution profile keyed by its name field, enabling per-DC routing. The default profile is determined by load_balancing.local_dc (or the first datacenter entry when load_balancing is absent). Use the optional routing block to direct reads and writes to specific datacenters. The keyspace must already exist; Feast does not create it automatically.

datacenters is mutually exclusive with hosts and secure_bundle_path.

{% code title="feature_store.yaml" %}

yaml

project: my_feature_repo
registry: data/registry.db
provider: local
online_store:
    type: cassandra
    keyspace: KeyspaceName
    datacenters:
        - name: dc1
          hosts:
              - 192.168.1.1
              - 192.168.1.2
          replication_factor: 3                 # optional, informational only
          replication_strategy: NetworkTopologyStrategy  # optional, informational only
        - name: dc2
          hosts:
              - 10.0.0.1
          replication_factor: 2                 # optional, informational only
    routing:                                    # optional
        read_dc: dc2                            # DC to use for reads  (default: load_balancing.local_dc)
        write_dc: dc1                           # DC to use for writes (default: load_balancing.local_dc)
    port: 9042                                  # optional
    username: user                              # optional
    password: secret                            # optional
    protocol_version: 5                         # optional
    load_balancing:                             # optional
        local_dc: 'dc1'                         # sets the default execution profile
        load_balancing_policy: 'TokenAwarePolicy(DCAwareRoundRobinPolicy)'  # optional
    read_concurrency: 100                       # optional
    write_concurrency: 100                      # optional

{% endcode %}

Example (Astra DB)

{% code title="feature_store.yaml" %}

yaml

project: my_feature_repo
registry: data/registry.db
provider: local
online_store:
    type: cassandra
    secure_bundle_path: /path/to/secure/bundle.zip
    keyspace: KeyspaceName
    username: Client_ID
    password: Client_Secret
    protocol_version: 4                                                     # optional
    load_balancing:                                                         # optional
        local_dc: 'eu-central-1'                                            # optional
        load_balancing_policy: 'TokenAwarePolicy(DCAwareRoundRobinPolicy)'  # optional
    read_concurrency: 100                                                   # optional
    write_concurrency: 100                                                  # optional

{% endcode %}

The full set of configuration options is available in CassandraOnlineStoreConfig. For a full explanation of configuration options please look at file sdk/python/feast/infra/online_stores/contrib/cassandra_online_store/README.md.

Storage specifications can be found at docs/specs/online_store_format.md.

Functionality Matrix

The set of functionality supported by online stores is described in detail here. Below is a matrix indicating which functionality is supported by the Cassandra online store.

	Cassandra
write feature values to the online store	yes
read feature values from the online store	yes
update infrastructure (e.g. tables) in the online store	yes
teardown infrastructure (e.g. tables) in the online store	yes
generate a plan of infrastructure changes	yes
support for on-demand transforms	yes
readable by Python SDK	yes
readable by Java	no
readable by Go	no
support for entityless feature views	yes
support for concurrent writing to the same key	no
support for ttl (time to live) at retrieval	no
support for deleting expired data	no
collocated by feature view	yes
collocated by feature service	no
collocated by entity key	no

To compare this set of functionality against other online stores, please see the full functionality matrix.