# IKV

## Description

[IKV](https://github.com/inlinedio/ikv-store) is a fully-managed embedded key-value store, primarily designed for storing ML features. Most key-value stores (think Redis or Cassandra) need a remote database cluster, whereas IKV allows you to utilize your existing application infrastructure to store data (cost efficient) and access it without any network calls (better performance). See detailed performance benchmarks and cost comparison with Redis on <https://inlined.io>. IKV can be used as an online-store in Feast, the rest of this guide goes over the setup.

## Getting started

Make sure you have Python and `pip` installed.

Install the Feast SDK and CLI: `pip install feast`

In order to use this online store, you'll need to install the IKV extra (along with the dependency needed for the offline store of choice). E.g.

* `pip install 'feast[gcp, ikv]'`
* `pip install 'feast[snowflake, ikv]'`
* `pip install 'feast[aws, ikv]'`
* `pip install 'feast[azure, ikv]'`

You can get started by using any of the other templates (e.g. `feast init -t gcp` or `feast init -t snowflake` or `feast init -t aws`), and then swapping in IKV as the online store as seen below in the examples.

### 1. Provision an IKV store

Go to <https://inlined.io> or email onboarding\[at]inlined.io

### 2. Configure

Update `my_feature_repo/feature_store.yaml` with the below contents:

{% code title="feature\_store.yaml" %}

```yaml
project: my_feature_repo
registry: data/registry.db
provider: local
online_store:
    type: ikv
    account_id: secret
    account_passkey: secret
    store_name: your-store-name
    mount_directory: /absolute/path/on/disk/for/ikv/embedded/index
```

{% endcode %}

After provisioning an IKV account/store, you should have an account id, passkey and store-name. Additionally you must specify a mount-directory - where IKV will pull/update (maintain) a copy of the index for online reads (IKV is an embedded database). It can be skipped only if you don't plan to read any data from this container. The mount directory path usually points to a location on local/remote disk.

The full set of configuration options is available in IKVOnlineStoreConfig at `sdk/python/feast/infra/online_stores/contrib/ikv_online_store/ikv.py`

## Functionality Matrix

The set of functionality supported by online stores is described in detail [here](https://docs.feast.dev/v0.41-branch/reference/overview#functionality). Below is a matrix indicating which functionality is supported by the IKV online store.

|                                                           | IKV |
| --------------------------------------------------------- | --- |
| 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                 | no  |
| 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            | yes |
| support for ttl (time to live) at retrieval               | no  |
| support for deleting expired data                         | no  |
| collocated by feature view                                | no  |
| collocated by feature service                             | no  |
| collocated by entity key                                  | yes |

To compare this set of functionality against other online stores, please see the full [functionality matrix](https://docs.feast.dev/v0.41-branch/reference/overview#functionality-matrix).