Initializing a specific connection string for Prisma Pulse
I'm currently using Prisma + Neon w/ tRPC hosted on Vercel. My Prisma is initialized using the DATABASE_URL connection string, which is a pooled connection.
Pulse requires a direct connection. Do I need to initialize a separate prisma instance for it to work, or will it work if I add a DIRECT_URL env variable to my deployment that contains the direct connection string (unpooled)?
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You would need to provide a direct connection string while configuring Pulse.
Pulse relies on API Keys to connect to your provided connection string.
Hi,
I'm asking specifically about connecting from the prisma client. Will it use the DIRECT_URL or does the DATABASE_URL have to be the direct connection?
Maybe I misunderstood your question. Please bear with me.
Pulse requires a direct connection.You are correct. This requirement is for listening to database changes. I assume you have already provided a direct connection string while configuring Prisma Pulse. If you did that, then pulse will work as expected.
Iām referring to connecting to Prisma Pulse from my application using Vercel.I assume here you are referring to listening to Pulse events via subscribe/stream? You will not need to initialize a separate prisma instance for Pulse to work. It should work as expected. Just as an FYI, Pulse cannot be directly used in Frontend (Reference)
yes, understood. However, it seems like using Pulse from my backend using a pooled connection doesn't work (subscriptions don't work).
When I changed my DATABASE_URL to remove the
-pooled part from my Neon connection string, everything started working as expected.Yes, that is expected. Prisma Pulse needs a direct connection string, not a -pooled one
That's what I was asking - will I need to initialize a separate prisma instance just for pulse?
since the current prisma instance uses a pooled connection
I was referring to this step, using a pooled connection string here is not recommended and instead a direct connection string should be used.
Did you pass a non-pooled connection string in this step? And then when you tried to subscribe to events, you weren't getting any?
this step is all set, it has the direct connection string
all good
I'm referring to connecting from Prisma on the client side
Okay, that's great.
The requirement for using a direct connection string was specific for this step, while setting up Pulse.
It's not a requirement for listening/subscribing to events. That should work fine on a pooled connection string, but it looks like it didn't work for you. Did you get any errors?
No errors. Just no events whatsoever.
It's been this way for months and I just got around to taking a look.
I have multiple Neon databases setup with Pulse and it's the same for all of them.
Okay, thanks for reporting!
I'll create a sample app to reproduce this behaviour. I'll use direct connection string while configuring pulse and will use a pooled connection string while listening for the events.
I'll check with our Pulse team and will either document this behaviour it if this is expected or will fix it š
thank you. Another compounding factor is that it is deployed to vercel and the listener runs as a serverless function
so the pooled connection might be interfering with the subscription socket
Noted.
Are the listeners on Nextjs server actions or API routes? Or are these serverless functions deployed on some other platform?
API routes using tRPC. No other platform.