xeno
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PPrisma
Created by xeno on 1/9/2025 in #help-and-questions
Tips for using Neon + Pulse + tRPC for real-time updates
I'm on the Pro plan, which guarantees "real-time" updates, Neon setup completed, Prisma client initialized using withPulse() and everything looks like it is setup correctly. However, new events from Pulse seem to arrive either very late or not arrive at all, regardless if I'm using stream() or subscribe(). Here's my tRPC router: 
 onChanges: protectedProcedure.subscription(async function* ({ ctx }) {
    const events = await ctx.db.modelToUpdate.subscribe();

    console.log("Initializing Pulse subscription");

    for await (const event of events) {
      console.log("document event", event);

      yield event;
    }
  }),
~
 onChanges: protectedProcedure.subscription(async function* ({ ctx }) {
    const events = await ctx.db.modelToUpdate.subscribe();

    console.log("Initializing Pulse subscription");

    for await (const event of events) {
      console.log("document event", event);

      yield event;
    }
  }),
~
And my frontend code: 
 const documentSubscription = api.xxx.onChanges.useSubscription(
    undefined,
    {
      onData: (data) => {
        console.log("Pulse update received");
      }
    }
  );
 const documentSubscription = api.xxx.onChanges.useSubscription(
    undefined,
    {
      onData: (data) => {
        console.log("Pulse update received");
      }
    }
  );
It seems like subscribe() doesn't deliver any events, while stream() delivers them in order, but very very late (can be several minutes after the actual database update).
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