docs: Expand Redis sink section

book/src/advanced/custom_network.md

@@ -1,6 +1,6 @@
 # Custom networks
 
-Required configuration connect Oura to a custom network (aka: not mainnet/testnet).
+Instructions on how to configure Oura for connecting to a custom network (aka: other than mainnet / testnet).
 
 ## Context
 

book/src/sinks/README.md

@@ -14,8 +14,6 @@ These are the existing sinks that are included as part the main _Oura_ codebase:
 - [AWS SQS](aws_sqs.md): a sink that sends each event as message to an AWS SQS queue.
 - [AWS Lamda](aws_lambda.md): a sink that invokes an AWS Lambda function for each event.
 - [AWS S3](aws_s3.md): a sink that saves the CBOR content of the blocks as an AWS S3 object.
-- [GCP PubSub](gcp_pubsub.md): a sink that sends each event as a message to a google cloud PubSub topic.
-- [GCP CloudFunction](gcp_cloudfunction.md): a sink that sends each event as JSON to a Cloud Function via HTTP.
 - [Redis Streams](redis_streams.md): a sink that sends each event into a Redis stream.
 
 New sinks are being developed, information will be added in this documentation to reflect the updated list. Contributions and feature request are welcome in our [Github Repo](https://github.com/txpipe/oura).

book/src/sinks/redis_streams.md

@@ -1,35 +1,45 @@
 # Redis Streams
 
-A sink that implements a _Redis Stream_ producer. The sink allows different stream strategies.
+A sink that outputs events into _Redis Stream_.
 
-It is possible to send all Event to a single stream or create multiple streams, one for each event type. 
-Both modes use `<millisecondsTime>-<sequenceNumber>` as unique entry ID (redis stream standard).
-With StreamStrategy `None` a single redis-stream is used for all events, a stream name can be defined by `stream_name`, the default stream name is `oura`. 
-StreamStrategy `ByEventType` creates its own redis-stream for each event type. By appling filters it is possible to define the streams which should be created. 
+_Redis Streams_ works as an append-only log where multiple consumers can read from the same queue while keeping independent offsets (as opposed to a PubSub topic where one subscriber affect the other). You can learn more about the _Streams_ feature in the official [Redis Documentation](https://redis.io/docs/manual/data-types/streams).
 
-The sink will use fingerprints as keys, if fingerprints are active otherwise the event type name in lowercase is used.
+This sink will process incoming events and send a JSON-encoded message of the payload for each one using the `XADD` command. The Redis instance can be local or remote.
 
 ## Configuration
 
-_Single Stream Mode:_
+Example configuration that sends all events into a single stream named `mystream` of a Redis instance running in port 6379 of the localhost.
 
 ```toml
 [sink]
 type = "Redis"
-redis_server = "redis://default:@127.0.0.1:6379/0"
+redis_server = "redis://localhost:6379"
 stream_name = "mystream"
-stream_strategy = "None"
 ```
 
-_Multi Stream Mode:_
+Example configuration that sends events into different streams (named by the type of event) of a Redis instance running in port 6379 of the localhost.
+
 ```toml
 [sink]
 type = "Redis"
-redis_server = "redis://default:@127.0.0.1:6379/0"
+redis_server = "redis://localhost:6379"
 stream_strategy = "ByEventType"
 ```
 
+### Section: `sink`
+
 - `type`: the literal value `Redis`.
 - `redis_server`: the redis server in the format `redis://[<username>][:<password>]@<hostname>[:port][/<db>]`
 - `stream_name` : the name of the redis stream for StreamStrategy `None`, default is "oura" if not specified
 - `stream_strategy` : `None` or `ByEventType`
+
+## Conventions
+
+It is possible to send all Event to a single stream or create multiple streams, one for each event type. By appling the [selection](/filters/selection) filter it is possible to define the streams which should be created. 
+
+The sink uses the default Redis convention to define the unique entry ID for each message sent to the stream ( `<millisecondsTime>-<sequenceNumber>`).
+
+Messages in Redis Streams are required to be `hashes` (maps between the string fields and the string values). This sink will serialize the event into a single-entry map with the following parts:
+
+- `key`: the [fingerprint](/filters/fingerprint) value if available, or the event type name.
+- `value`: the json-encoded payload of the event.