4 posts tagged with "WebAssembly"

On the heels of our last feature release, we are excited to announce a new feature: Exograph Playground in the browser! Thanks to the magic of WebAssembly, you can now run Exograph servers entirely in your browser, so you can try Exograph without even installing it. That's right, we run a Tree Sitter parser, typechecker, GraphQL runtime, and Postgres all in your browser.

We are excited to announce that Exograph can now run as a Cloudflare Worker! This new capability allows deploying Exograph servers at the edge, closer to your users, and with lower latency.

Cloudflare Workers is a good choice for deploying APIs due to the following characteristics:

• They scale automatically to handle changing traffic patterns, including scaling down to zero.
• They have an excellent cold start time (in milliseconds).
• They get deployed in Cloudflare's global network, thus the workers can be placed optimally for better latency and performance.
• They have generous free tier limits that can be sufficient for many applications.

In the previous post, we implemented a simple Cloudflare Worker in Rust/WebAssembly connecting to a Neon Postgres database and measured end-to-end latency. Without any pooling, we got a mean response time of 345ms.

The two issues we suspected for the high latency were:

Establishing connection to the database: The worker creates a new connection for each request. Given that a secure connection, it takes 7+ round trips. Not surprisingly, latency is high.

Executing the query: The query method in our code causes the Rust Postgres driver to make two round trips: to prepare the statement and to bind/execute the query. It also sends a one-way message to close the prepared statement.

In this part, we will deal with connection establishment time by introducing a pool. We will fork the driver to deal with multiple round trips (which incidentally also helps with connection pooling). We will also learn a few things about Postgres's query protocol.

We have been working on enabling Exograph on WebAssembly. Since we have implemented Exograph using Rust, it was natural to target WebAssembly. You can soon build secure, flexible, and efficient GraphQL backends using Exograph and run them at the edge.

During our journey towards WebAssembly support, we learned a few things to improve the latency of Rust-based programs targeting WebAssembly in Cloudflare Workers connecting to Postgres. This two-part series shares those learnings. In this first post, we will set up a simple Cloudflare Worker connecting to a Postgres database and get baseline latency measurements. In the next post, we will explore various ways to improve it.