workers-sdk VS litestream

Workers

https://github.com/cloudflare/workers-sdk/blob/main/packages...

The Wrangler, Cloudflare's Developer Platform command-line interface (CLI), allows you to manage Worker projects and has an in-built Miniflare, which runs an HTTP server.

/** * Welcome to Cloudflare Workers! This is your first worker. * * - Run `npm run dev` in your terminal to start a development server * - Open a browser tab at http://localhost:8787/ to see your worker in action * - Run `npm run deploy` to publish your worker * * Learn more at https://developers.cloudflare.com/workers/ */ export interface Env { // Example binding to KV. Learn more at https://developers.cloudflare.com/workers/runtime-apis/kv/ // MY_KV_NAMESPACE: KVNamespace; // // Example binding to Durable Object. Learn more at https://developers.cloudflare.com/workers/runtime-apis/durable-objects/ // MY_DURABLE_OBJECT: DurableObjectNamespace; // // Example binding to R2. Learn more at https://developers.cloudflare.com/workers/runtime-apis/r2/ // MY_BUCKET: R2Bucket; // // Example binding to a Service. Learn more at https://developers.cloudflare.com/workers/runtime-apis/service-bindings/ // MY_SERVICE: Fetcher; // // Example binding to a Queue. Learn more at https://developers.cloudflare.com/queues/javascript-apis/ // MY_QUEUE: Queue; } export default { async fetch(request: Request, env: Env, ctx: ExecutionContext): Promise { return new Response('Hello World!'); }, };

$ npm create cloudflare@latest using create-cloudflare version 2.9.0 ╭ Create an application with Cloudflare Step 1 of 3 │ ├ In which directory do you want to create your application? │ dir ./apps/worker │ ├ What type of application do you want to create? │ type "Hello World" Worker │ ├ Do you want to use TypeScript? │ yes typescript │ ├ Copying files from "hello-world" template │ ├ Retrieving current workerd compatibility date │ compatibility date 2023-12-18 │ ╰ Application created ╭ Installing dependencies Step 2 of 3 │ ├ Installing dependencies │ installed via `npm install` │ ├ Installing @cloudflare/workers-types │ installed via npm │ ├ Adding latest types to `tsconfig.json` │ skipped couldn't find latest compatible version of @cloudflare/workers-types │ ╰ Dependencies Installed ╭ Deploy with Cloudflare Step 3 of 3 │ ├ Do you want to deploy your application? │ no deploy via `npm run deploy` │ ├ APPLICATION CREATED Deploy your application with npm run deploy │ │ Navigate to the new directory cd apps/worker │ Run the development server npm run start │ Deploy your application npm run deploy │ Read the documentation https://developers.cloudflare.com/workers │ Stuck? Join us at https://discord.gg/cloudflaredev │ ╰ See you again soon!

Except that there is. Cloudflare is pretty great for free SSL certificates and DNS management, but they also offer a free Workers plan. A Cloudflare worker is basically JavaScript code that runs on Cloudflare's edge network and handles HTTP traffic. You can do a lot with workers, including modifying/rewriting HTML responses. You can probably see where this is going: If a worker can modify HTML responses, then it can inject the umami script into every HTML response.

Cloudflare Workers

And what about the DX of using Workers with Pages?

I tried to use that recently and it was a disaster. I wrote about my experience here:

https://twitter.com/pierbover/status/1641474067013271552

I then opened these two issues:

https://github.com/cloudflare/workers-sdk/issues/2962

https://github.com/cloudflare/workers-sdk/issues/2964

I ended up moving the project over to Netlify + Edge functions. I had it all working in like 5-10 mins as it should. Took me two hours to figure out why Workers weren't working in my Pages project, and could never get Workers working properly with my Astro project.

I think you're working exclusively on the engine of Workers which is really top notch, but Cloudflare really needs to improve the outer layer which affects DX considerably.

If you think this is a bug, please open an issue at: https://github.com/cloudflare/workers-sdk/issues/new/choose ```

I have not, but I keep meaning to collate everything I've learned into a set of useful defaults just to remind myself what settings I should be enabling and why.

Regarding Litestream, I learned pretty much all I know from their documentation: https://litestream.io/

This presentation is focused on the use-case of vertically scaling a single server and driving everything through that app server, which is running SQLite embedded within your application process.

This is the sweet-spot for SQLite applications, but there have been explorations and advances to running SQLite across a network of app servers. LiteFS (https://fly.io/docs/litefs/), the sibling to Litestream for backups (https://litestream.io), is aimed at precisely this use-case. Similarly, Turso (https://turso.tech) is a new-ish managed database company for running SQLite in a more traditional client-server distribution.

This post intends to help you setup replication for SQLite using Litestream.

I've been messing around with litestream. It is so cool. And, I either found a bug in the -timestamp switch or don't understand it correctly.

What I want to do is time travel into my sqlite database. I'm trying to do some forensics on why my web service returned the wrong data during a production event. Unfortunately, after the event, someone deleted records from the database and I'm unsure what the data looked like and am having trouble recreating the production issue.

Litestream has this great switch: -timestamp. If you use it (AFAICT) you can time travel into your database and go back to the database state at that moment. However, it does not seem to work as I expect it to:

https://github.com/benbjohnson/litestream/issues/564

I have the entirety of the sqlite database from the production event as well. Is there a way I could cycle through the WAL files and restore the database to the point in time before the records I need were deleted?

Will someone take sqlite and compile it into the browser using WASM so I can drag a sqlite database and WAL files into it and then using a timeline slider see all the states of the database over time? :)

We're using SQLite in production very heavily with millions of databases and fairly high operations throughput.

But we did run into some scariness around trying to use Litestream that put me off it for the time being. Litestream is really cool but it is also very much a cool hack and the risk of database corruption issues feels very real.

The scariness I ran into was related to this issue https://github.com/benbjohnson/litestream/issues/510

Litestream is a library that allows you to easily create backups. You can probably just do analytic queries on the backup data and reduce load on your server.

https://litestream.io/

One possible strategy is to have one directory/file per customer which is one SQLite file. But then as the user logs in, you have to look up first what database they should be connected to.

OR somehow derive it from the user ID/username. Keeping all the customer databases in a single directory/disk and then constantly "lite streaming" to S3.

Because each user is isolated, they'll be writing to their own database. But migrations would be a pain. They will have to be rolled out to each database separately.

One upside is, you can give users the ability to take their data with them, any time. It is just a single file.

[0]. https://litestream.io/

Upstream Kuma uses a local SQLite database to store account data, configuration for services to monitor, notification settings, and more. To make sure that our data is available across redeploys, we will bundle Uptime Kuma with Litestream, a project that implements streaming replication for SQLite databases to a remote object storage provider. Effectively, this allows us to treat the local SQLite database as if it were securely stored in a remote database.