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I totally agree. Having a single point of entry gives us some small benefits like a single connection/simplified deployments but it isn't efficient to have a pr

I totally agree. Having a single point of entry gives us some small benefits like a single connection/simplified deployments but it isn't efficient to have a provider connected on one node in a cluster and have to forward data to subscribers on another just because of how they were distributed by a load-balancer. Theres actually an action in the handshake protocol which allows a node in a cluster to redirect a connection to a different/more optimal node. It was used for multi-tenancy clusters previously. In theory you can run multiple isolated clusters (or individual nodes) and have multiple connections from the client, routed based on which subscription lives where. It's a pattern I have been talking about with a couple of users but it hasn't been required by anyone yet. It isn't as efficient as doing it on a network layer but it at least reduced intercluster traffic dramatically.

saurik 7y ago
I used to be really concerned about this, but one day I sat down and did the math and realized that the worst case scenario is that I'd have no more than two times as many messages, which means this isn't a scalability issue: if a topic has N subscribers, at bare minimum you are going to have N+1 messages to send a given event (one to receive it into the cluster, and N to dispatch it to the subscribers); if everyone is connected to some random machine, then you need to take the incoming event and send it to the right internal machine that is storing that topic (which is one extra message) and then that machine will need to indirectly send the message to the connecting computers of the subscribers (which is one extra message per subscriber), so you end up with 2N+2 messages. The alternative, where users cluster themselves based on topic with their entry connections, is that these individual end users have to maintain a ton of separate connections for inbound messages for each of the topics they are interested in, which is often going to work out to be much worse for everyone involved.

saurik 7y ago

I used to be really concerned about this, but one day I sat down and did the math and realized that the worst case scenario is that I'd have no more than two times as many messages, which means this isn't a scalability issue: if a topic has N subscribers, at bare minimum you are going to have N+1 messages to send a given event (one to receive it into the cluster, and N to dispatch it to the subscribers); if everyone is connected to some random machine, then you need to take the incoming event and send it to the right internal machine that is storing that topic (which is one extra message) and then that machine will need to indirectly send the message to the connecting computers of the subscribers (which is one extra message per subscriber), so you end up with 2N+2 messages. The alternative, where users cluster themselves based on topic with their entry connections, is that these individual end users have to maintain a ton of separate connections for inbound messages for each of the topics they are interested in, which is often going to work out to be much worse for everyone involved.