Question: Disconnect ws connection from server side

[shunsukew]

Is it possible to disconnect ws connection from server side by using jsonrpsee api?

What I'm thinking of is disconnect ws connection from server side (not from client side) under specific situations.

[shunsukew]

As a background, software that proxying subscriptions (for e.g. Subway), proxy silently stop sending responses to clients when upstream ws connection is disconnected.

To avoid such situation, what I came up with are

• proxy re-subscribe once upstream connection re-established.
• Disconnect client side ws connection, and let clients to have chance to reconnect&subscribe.

[niklasad1]

Hey @shunsukew

Is it possible to disconnect ws connection from server side by using jsonrpsee api?

There is no dedicated API in jsonrpsee for the server-side the close down connections but it's possible to use to the low-level API with rpc middleware (which is a bit complicated to use)

There is a similar issue regarding this #1427

When talking about subscriptions specifically I just want clarify that a few options exist to inform the client without closing the connection:

• Reject the subscription i.e, call Subscription::reject which just returns an error the origin RPC call
• Send a special "error notification" or "application specific notification" before closing down subscription
• Silently just drop the subscription

[shunsukew]

Hello, Thank you for the information!

Reject the subscription i.e, call Subscription::reject which just returns an error the origin RPC call

I was looking for a way to disconnect after accepting.

Send a special "error notification" or "application specific notification" before closing down subscription

In our usecase, just proxying standard subscribe calls (e.g. eth_subscribe newHeads), quite hard to add custom error notification, client sdk doesn't understand it because it's not eth/substrate standards.

Thank you for the sharing low level apis! I think this is the only way to disconnect after accepting PendingSubscription.
For now, we have 2 different ws connection (client <> proxy and proxy <> upstream), and decided to re-subscribe after re-established the upstream connection, while keeping client side ws connection stay connected.
Possibly, will find a way to use those low level apis to disconnect connection itself.