docs: document health connection

README.md

@@ -399,7 +399,7 @@ Date: Mon, 27 Jun 2022 14:26:45 GMT
 
 As part of making this API performant, all reading endpoints support long-polling as an efficient alternative to regular (repeated) polling. Using this function requires the following parameters:
 
-- `wait_count`: The API call will block until at least this many results are available. If there are more matching tasks/results avalible all of them will be returned.
+- `wait_count`: The API call will block until at least this many results are available. If there are more matching tasks/results available all of them will be returned.
 - `wait_time`: ... or this time has passed (if not stated differently, e.g., by adding 'm', 'h', 'ms', ..., this is interpreted as seconds), whichever comes first.
 
 For example, retrieving a task's results:
@@ -629,6 +629,12 @@ Samply.Beam encrypts all information in the `body` fields of both Tasks and Resu
 
 The data is symmetrically encrypted using the Authenticated Encryption with Authenticated Data (AEAD) algorithm "XChaCha20Poly1305", a widespread algorithm (e.g., mandatory for the TLS protocol), regarded as highly secure by experts. The used [chacha20poly1305 library](https://docs.rs/chacha20poly1305/latest/chacha20poly1305/) was sublected to a [security audit](https://research.nccgroup.com/2020/02/26/public-report-rustcrypto-aes-gcm-and-chacha20poly1305-implementation-review/), with no significant findings. The randomly generated symmetric keys are encapsulated in a RSA encrypted ciphertext using OAEP Padding. This ensures, that only the intended recipients can decrypt the key and subsequently the transferred data.
 
+### Health check connection
+
+The beam proxy tries to keep a permanent connection to the broker to make it possible to see which sites are currently connected.
+This also allows us to detected invalid connection states such as multiple proxies with the same proxy id connecting simultaneously.
+In that case the second proxy trying to connect will receive a 409 status code and shut down.
+
 ## Roadmap
 
 - [X] API Key authentication of local applications