# Tracker Stores

All conversations are stored within a tracker store. Rasa Core provides implementations for different store types out of the box. If you want to use another store, you can also build a custom tracker store by extending the TrackerStore class.

## InMemoryTrackerStore (default)
### Description
InMemoryTrackerStore is the default tracker store. It is used if no other tracker store is configured. It stores the conversation history in memory.

### Note
As this store keeps all history in memory the entire history is lost if you restart Rasa Core.

### Configuration
To use the InMemoryTrackerStore no configuration is needed.

## SQLTrackerStore
### Description
`SQLTrackerStore` can be used to store the conversation history in an SQL database. Storing your trackers this way allows you to query the event database by sender_id, timestamp, action name, intent name and typename.

### Configuration
To set up Rasa Core with SQL the following steps are required:
1. Add required configuration to your endpoints.yml

```
tracker_store:
    type: SQL
    dialect: "sqlite"  # the dialect used to interact with the db
    url: ""  # (optional) host of the sql db, e.g. "localhost"
    db: "rasa.db"  # path to your db
    username:  # username used for authentication
    password:  # password used for authentication
    query: # optional dictionary to be added as a query string to the connection URL
      driver: my-driver
```

3. To start the Rasa Core server using your SQL backend, add the `--endpoints` flag, e.g.:

```
rasa run -m models --endpoints endpoints.yml
```

### Parameters
- `domain` (default: `None`): Domain object associated with this tracker store
- `dialect` (default: `sqlite`): The dialect used to communicate with your SQL backend. Consult the [SQLAlchemy docs](https://docs.sqlalchemy.org/en/latest/core/engines.html#database-urls) for available dialects.
- `host` (default: `None`): URL of your SQL server
- `port` (default: `None`): Port of your SQL server
- `db` (default: `rasa.db`): The path to the database to be used
- `username` (default: `None`): The username which is used for authentication
- `password` (default: `None`): The password which is used for authentication
- `event_broker` (default: `None`): Event broker to publish events to
- `login_db` (default: `None`): Alternative database name to which initially connect, and create the database specified by db (PostgreSQL only)
- `query` (default: `None`): Dictionary of options to be passed to the dialect and/or the DBAPI upon connect

## RedisTrackerStore
### Description
RedisTrackerStore can be used to store the conversation history in [Redis](https://redis.io/). Redis is a fast in-memory key-value store which can optionally also persist data.

### Configuration
To set up Rasa Core with Redis the following steps are required:
1. Start your Redis instance
2. Add required configuration to your endpoints.yml

```
tracker_store:
    type: redis
    url: <url of the redis instance, e.g. localhost>
    port: <port of your redis instance, usually 6379>
    db: <number of your database within redis, e.g. 0>
    password: <password used for authentication>
    use_ssl: <whether or not the communication is encrypted, default `false`>
```

3. To start the Rasa Core server using your configured Redis instance, add the `--endpoints` flag, e.g.:

```
rasa run -m models --endpoints endpoints.yml
```

### Parameters
- `url` (default: `localhost`): The url of your redis instance
- `port` (default: `6379`): The port which redis is running on
- `db` (default: `0`): The number of your redis database
- `password` (default: `None`): Password used for authentication (`None` equals no authentication)
- `record_exp` (default: `None`): Record expiry in seconds

## MongoTrackerStore
### Description
MongoTrackerStore can be used to store the conversation history in [Mongo](https://www.mongodb.com/). MongoDB is a free and open-source cross-platform document-oriented NoSQL database.

### Configuration
1. Start your MongoDB instance.
2. Add required configuration to your endpoints.yml

```
tracker_store:
    type: mongod
    url: <url to your mongo instance, e.g. mongodb://localhost:27017>
    db: <name of the db within your mongo instance, e.g. rasa>
    username: <username used for authentication>
    password: <password used for authentication>
    auth_source: <database name associated with the user’s credentials>
```

You can also add more advanced configurations (like enabling ssl) by appending a parameter to the url field, e.g. mongodb://localhost:27017/?ssl=true

3. To start the Rasa Core server using your configured MongoDB instance, add the `--endpoints` flag, e.g.:

```
rasa run -m models --endpoints endpoints.yml
```

### Parameters
- `url` (default: `mongodb://localhost:27017`): URL of your MongoDB
- `db` (default: `rasa`): The database name which should be used
- `username` (default: `0`): The username which is used for authentication
- `password` (default: `None`): The password which is used for authentication
- `collection` (default: `conversations`): The collection name which is used to store the conversations
- `auth_source` (default: `admin`): database name associated with the user’s credentials.

## Custom Tracker Store
### Description
If you require a tracker store which is not available out of the box, you can implement your own. This is done by extending the base class TrackerStore.

_class_`rasa.core.tracker_store.TrackerStore`( _domain_, _event_broker=None_, _retrieve_events_from_previous_conversation_sessions=False_)

### Steps
1. Extend the TrackerStore base class. Note that your constructor has to provide a parameter `url`.
2. In your endpoints.yml put in the module path to your custom tracker store and the parameters you require:

```
tracker_store:
  type: path.to.your.module.Class
  url: localhost
  a_parameter: a value
  another_parameter: another value
```