diff --git a/doc/book/reference-manual/configuration.md b/doc/book/reference-manual/configuration.md index 84aaf511..e134a83f 100644 --- a/doc/book/reference-manual/configuration.md +++ b/doc/book/reference-manual/configuration.md @@ -333,6 +333,7 @@ Since `v0.8.0`, Garage can use alternative storage backends as follows: | --------- | ----------------- | ------------- | | [LMDB](https://www.symas.com/lmdb) (since `v0.8.0`, default since `v0.9.0`) | `"lmdb"` | `/db.lmdb/` | | [Sqlite](https://sqlite.org) (since `v0.8.0`) | `"sqlite"` | `/db.sqlite` | +| [Fjall](https://github.com/fjall-rs/fjall) (**experimental support** since `v1.3.0`) | `"fjall"` | `/db.fjall/` | | [Sled](https://sled.rs) (old default, removed since `v1.0`) | `"sled"` | `/db/` | Sled was supported until Garage v0.9.x, and was removed in Garage v1.0. @@ -369,6 +370,14 @@ LMDB works very well, but is known to have the following limitations: so it is not the best choice for high-performance storage clusters, but it should work fine in many cases. +- Fjall: a storage engine based on LSM trees, which theoretically allow for + higher write throughput than other storage engines that are based on B-trees. + Using Fjall could potentially improve Garage's performance significantly in + write-heavy workloads. **Support for Fjall is experimental at this point**, + we have added it to Garage for evaluation purposes only. **Do not use it for + production-critical workloads.** + + It is possible to convert Garage's metadata directory from one format to another using the `garage convert-db` command, which should be used as follows: @@ -406,6 +415,7 @@ Here is how this option impacts the different database engines: |----------|------------------------------------|-------------------------------| | Sqlite | `PRAGMA synchronous = OFF` | `PRAGMA synchronous = NORMAL` | | LMDB | `MDB_NOMETASYNC` + `MDB_NOSYNC` | `MDB_NOMETASYNC` | +| Fjall | default options | not supported | Note that the Sqlite database is always ran in `WAL` mode (`PRAGMA journal_mode = WAL`). diff --git a/src/db/open.rs b/src/db/open.rs index fbd8d74a..d5469b58 100644 --- a/src/db/open.rs +++ b/src/db/open.rs @@ -124,8 +124,12 @@ pub fn open_db(path: &PathBuf, engine: Engine, opt: &OpenOpt) -> Result { #[cfg(feature = "fjall")] Engine::Fjall => { info!("Opening Fjall database at: {}", path.display()); - let fsync_ms = opt.fsync.then(|| 1000 as u16); - let mut config = fjall::Config::new(path).fsync_ms(fsync_ms); + if opt.fsync { + return Err(Error( + "metadata_fsync is not supported with the Fjall database engine".into(), + )); + } + let mut config = fjall::Config::new(path); if let Some(block_cache_size) = opt.fjall_block_cache_size { config = config.cache_size(block_cache_size.try_into().unwrap()); }