Senden Architecture

Our entire stack is fully horizontally sclable. We use our own orchestration software built using Wireguard.

Domain Schema

Backend

[countrycode]-[instanceid].backends.senden.chat

Example: ch-01.backends.senden.chat

Voice Relays

[countrycode]-[instanceid].relays.senden.chat

Example: ch-01.relays.senden.chat

Self hosted servers

[server-id].sendencontent.dev -> maps to public ip of server

Example: awesome-server.sendenservers.dev

Storage

Everything is stored on an s3 compatible server. This is currently https://senden-cdn.objects.eplg.cloud.

Orchestration

On each new session, your client calls https://discovery.senden.chat/all.

This automatically selects the nearest backend and voice server. In case of multiple storage backends, this also returns another cdn url other than the one defined above.

Our orchestrator fetches data from our prometheus server to determine if a server is fully utilized. It currently works by filling Servers to 85% utiliziation. As soon as this is reached, another instance is automatically generated.

Servers / Hosting

Since the Senden Association is ran by the same people at https://wireway.ch, which own their own servers.

We run them 90% of the time on Solar power which keeps down cost a lot.

Our only fixed cost is our Network uplink, which currently has a speed of 25 Gbps. Each of our 10 nodes is connected to either a direct 10Gbps or 2.5Gbps port.

We benchmarked Senden over our entire Servers to be able to support about 750'000 DAU. This should be way more than enough for now and we do not need external compute.

Infrastructure Transparency is going to be available at https://transparency.senden.chat at a later point in time.

Funding & Future

Since our cost is relatively low, we can sustain Senden for extremely long.

Our future plans which will cost around 4 euros can subsidize 570 users on average.

Until reliable income is guaranteed, we fund senden entirely ourself.