litefs VS litestack

Firstly, LiteJob's reliance on SQLite inherently restricts its horizontal scaling capabilities. Unlike other databases, SQLite is designed for single-machine use, making it challenging to distribute workload across multiple servers. This can certainly be done using novel technologies like LiteFS, but it is far from intuitive.

Im curious to know if others have tried out Turso or LiteFS or any of the newer edge db providers that are popping up in 'real world' applications and what your experiences have been?

Author here. I think we could have set better expectations with our Postgres docs. It wasn't meant to be a managed service but rather some tooling to help streamline setting up a database and replicas. I'm sorry about the troubles you've had and that it's come off as us being disingenuous. We blog about things that we're working on and find interesting. It's not meant say that we've figured everything out but rather this is what we've tried.

As for this post, it's not managed SQLite but rather an open source project called LiteFS [1]. You can run it anywhere that runs Linux. We use it in few places in our infrastructure and found that sharing the underlying database for internal tooling was really helpful for that use case.

[1]: https://github.com/superfly/litefs

#. SQLite WAL mode

From https://www.sqlite.org/isolation.html https://news.ycombinator.com/item?id=32247085 :

> [sqlite] WAL mode permits simultaneous readers and writers. It can do this because changes do not overwrite the original database file, but rather go into the separate write-ahead log file. That means that readers can continue to read the old, original, unaltered content from the original database file at the same time that the writer is appending to the write-ahead log

#. superfly/litefs: aFUSE-based file system for replicating SQLite https://github.com/superfly/litefs

#. sqldiff: https://www.sqlite.org/sqldiff.html https://news.ycombinator.com/item?id=31265005

#. dolthub/dolt: https://github.com/dolthub/dolt

> Dolt can be set up as a replica of your existing MySQL or MariaDB database using standard MySQL binlog replication. Every write becomes a Dolt commit. This is a great way to get the version control benefits of Dolt and keep an existing MySQL or MariaDB database.

#. pganalyze/libpg_query: https://github.com/pganalyze/libpg_query :

> C library for accessing the PostgreSQL parser outside of the server environment

#. Ibis + Substrait [ + DuckDB ]

> ibis strives to provide a consistent interface for interacting with a multitude of different analytical execution engines, most of which (but not all) speak some dialect of SQL.

> Today, Ibis accomplishes this with a lot of help from `sqlalchemy` and `sqlglot` to handle differences in dialect, or we interact directly with available Python bindings (for instance with the pandas, datafusion, and polars backends).

> [...] `Substrait` is a new cross-language serialization format for communicating (among other things) query plans. It's still in its early days, but there is already nascent support for Substrait in Apache Arrow, DuckDB, and Velox.

#. benbjohnson/postlite: https://github.com/benbjohnson/postlite

> postlite is a network proxy to allow access to remote SQLite databases over the Postgres wire protocol. This allows GUI tools to be used on remote SQLite databases which can make administration easier.

> The proxy works by translating Postgres frontend wire messages into SQLite transactions and converting results back into Postgres response wire messages. Many Postgres clients also inspect the pg_catalog to determine system information so Postlite mirrors this catalog by using an attached in-memory database with virtual tables. The proxy also performs minor rewriting on these system queries to convert them to usable SQLite syntax.

> Note: This software is in alpha. Please report bugs. Postlite doesn't alter your database unless you issue INSERT, UPDATE, DELETE commands so it's probably safe. If anything, the Postlite process may die but it shouldn't affect your database.

#. > "Hosting SQLite Databases on GitHub Pages" (2021) re: sql.js-httpvfs, DuckDB https://news.ycombinator.com/item?id=28021766

#. awesome-db-tools https://github.com/mgramin/awesome-db-tools

LiteFS works sorta like that. It provides read replicas on all your application servers so you can use it just like vanilla SQLite for queries.

Write transactions have to occur on the primary node but that's mostly because of latency. SQLite operates in serializable isolation so it only allows one transaction at a time. If you wanted to have all nodes write then you'd need to acquire a lock on one node and then update it and then release the lock. We actually allow this on LiteFS using something called "write forwarding" but it's pretty slow so I wouldn't suggest it for regular use.

We're adding an optional a query API over HTTP [1] soon as well. It's inspired by Turso's approach. That'll let you issue one or more queries in a batch over HTTP and they'll be run in a single transaction.

[1]: https://github.com/superfly/litefs/issues/326

Basically, LiteFS: https://github.com/superfly/litefs

And then some load balancer cleverness that reroutes writes to a specific VM: https://fly.io/blog/globally-distributed-postgres/

But my guess is they'll have an alternate implementation or something like LiteFS in Deno Deploy that will make this substantially more interesting when running in the Cloud.

The benchmarks for LiteCache are impressive, with a small caveat. While LiteCache outperforms a local Redis installation for every read operation, it seems like there's still room for improvement, especially for large write payloads.

Luckily, the official LiteStack benchmarks include measurements for LiteCable against Redis, which I am going to quote here.

Let's quickly look into how LiteJob uses SQLite to implement a job queueing system. In essence, the class Litequeue interfaces with the SQLite queue table. This table's columns, like id, name, fire_at, value, and created_at, store and manage job details.

Next, we install LiteStack using the shipped generator:

Related: I wrote a piece last week on deploying Rails apps to production on Fly.io at https://fly.io/ruby-dispatch/sqlite-and-rails-in-production/

The work that’s made this possible is:

1. Litestack - https://github.com/oldmoe/litestack

2. Fly.io’s work on the dockerfile-rails generator detecting Sqlite and Litestack in a Rails project, then setting up sane defaults for where that data is stored and persisted in production. This is all done behind the scenes with no intervention required from the person deploying.

3. Servers are overall faster and more powerful

I hope more Rails hosts make it easier and safer to deploy Sqlite to production. It will lower costs and reduce complexity for folks deploying apps.

Didn't know that one! The litestack.gemspec shows it's a wrapper around the sqlite3 gem. So, not really comparable...

I’m working on this for Rails apps at https://github.com/oldmoe/litestack/pull/12

The idea is that people with small-to-medium size Rails Turbo apps should be able to deploy them without needing Redis or Postgres.

I’ve gotten as far as deploying this stack _without_ LiteFS and it works great. The only downside is the application queues requests on deploy, but for some smaller apps it’s acceptable to have the client wait for a few seconds while the app restarts.

When I get that PR merged I’ll write about how it works on Fly and publish it to https://fly.io/ruby-dispatch/.

Rails is the way to go. The productivity of the Ruby language is insane. It's battle tested for decades and you can easily scale your prototype.

If you want a simple app served on a single host you can try LiteStack [0] so you don't need a Redis/Postgres/Sidekiq instance, just SQLite.

Laravel is also good if you like PHP language.

[0] https://github.com/oldmoe/litestack