garage/src/db/bin/convert.rs

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Abstract database behind generic interface and implement alternative drivers (#322) - [x] Design interface - [x] Implement Sled backend - [x] Re-implement the SledCountedTree hack ~~on Sled backend~~ on all backends (i.e. over the abstraction) - [x] Convert Garage code to use generic interface - [x] Proof-read converted Garage code - [ ] Test everything well - [x] Implement sqlite backend - [x] Implement LMDB backend - [ ] (Implement Persy backend?) - [ ] (Implement other backends? (like RocksDB, ...)) - [x] Implement backend choice in config file and garage server module - [x] Add CLI for converting between DB formats - Exploit the new interface to put more things in transactions - [x] `.updated()` trigger on Garage tables Fix #284 **Bugs** - [x] When exporting sqlite, trees iterate empty?? - [x] LMDB doesn't work **Known issues for various back-ends** - Sled: - Eats all my RAM and also all my disk space - `.len()` has to traverse the whole table - Is actually quite slow on some operations - And is actually pretty bad code... - Sqlite: - Requires a lock to be taken on all operations. The lock is also taken when iterating on a table with `.iter()`, and the lock isn't released until the iterator is dropped. This means that we must be VERY carefull to not do anything else inside a `.iter()` loop or else we will have a deadlock! Most such cases have been eliminated from the Garage codebase, but there might still be some that remain. If your Garage-over-Sqlite seems to hang/freeze, this is the reason. - (adapter uses a bunch of unsafe code) - Heed (LMDB): - Not suited for 32-bit machines as it has to map the whole DB in memory. - (adpater uses a tiny bit of unsafe code) **My recommendation:** avoid 32-bit machines and use LMDB as much as possible. **Converting databases** is actually quite easy. For example from Sled to LMDB: ```bash cd src/db cargo run --features cli --bin convert -- -i path/to/garage/meta/db -a sled -o path/to/garage/meta/db.lmdb -b lmdb ``` Then, just add this to your `config.toml`: ```toml db_engine = "lmdb" ``` Co-authored-by: Alex Auvolat <alex@adnab.me> Reviewed-on: https://git.deuxfleurs.fr/Deuxfleurs/garage/pulls/322 Co-authored-by: Alex <alex@adnab.me> Co-committed-by: Alex <alex@adnab.me>
2022-06-08 08:01:44 +00:00
use std::path::PathBuf;
use garage_db::*;
use clap::Parser;
/// K2V command line interface
#[derive(Parser, Debug)]
#[clap(author, version, about, long_about = None)]
struct Args {
/// Input DB path
#[clap(short = 'i')]
input_path: PathBuf,
/// Input DB engine
#[clap(short = 'a')]
input_engine: String,
/// Output DB path
#[clap(short = 'o')]
output_path: PathBuf,
/// Output DB engine
#[clap(short = 'b')]
output_engine: String,
}
fn main() {
let args = Args::parse();
pretty_env_logger::init();
match do_conversion(args) {
Ok(()) => println!("Success!"),
Err(e) => eprintln!("Error: {}", e),
}
}
fn do_conversion(args: Args) -> Result<()> {
let input = open_db(args.input_path, args.input_engine)?;
let output = open_db(args.output_path, args.output_engine)?;
output.import(&input)?;
Ok(())
}
fn open_db(path: PathBuf, engine: String) -> Result<Db> {
match engine.as_str() {
"sled" => {
let db = sled_adapter::sled::Config::default().path(&path).open()?;
Ok(sled_adapter::SledDb::init(db))
}
"sqlite" | "sqlite3" | "rusqlite" => {
let db = sqlite_adapter::rusqlite::Connection::open(&path)?;
Ok(sqlite_adapter::SqliteDb::init(db))
}
"lmdb" | "heed" => {
std::fs::create_dir_all(&path).map_err(|e| {
Error(format!("Unable to create LMDB data directory: {}", e).into())
})?;
2022-06-09 12:55:20 +00:00
let map_size = lmdb_adapter::recommended_map_size();
Abstract database behind generic interface and implement alternative drivers (#322) - [x] Design interface - [x] Implement Sled backend - [x] Re-implement the SledCountedTree hack ~~on Sled backend~~ on all backends (i.e. over the abstraction) - [x] Convert Garage code to use generic interface - [x] Proof-read converted Garage code - [ ] Test everything well - [x] Implement sqlite backend - [x] Implement LMDB backend - [ ] (Implement Persy backend?) - [ ] (Implement other backends? (like RocksDB, ...)) - [x] Implement backend choice in config file and garage server module - [x] Add CLI for converting between DB formats - Exploit the new interface to put more things in transactions - [x] `.updated()` trigger on Garage tables Fix #284 **Bugs** - [x] When exporting sqlite, trees iterate empty?? - [x] LMDB doesn't work **Known issues for various back-ends** - Sled: - Eats all my RAM and also all my disk space - `.len()` has to traverse the whole table - Is actually quite slow on some operations - And is actually pretty bad code... - Sqlite: - Requires a lock to be taken on all operations. The lock is also taken when iterating on a table with `.iter()`, and the lock isn't released until the iterator is dropped. This means that we must be VERY carefull to not do anything else inside a `.iter()` loop or else we will have a deadlock! Most such cases have been eliminated from the Garage codebase, but there might still be some that remain. If your Garage-over-Sqlite seems to hang/freeze, this is the reason. - (adapter uses a bunch of unsafe code) - Heed (LMDB): - Not suited for 32-bit machines as it has to map the whole DB in memory. - (adpater uses a tiny bit of unsafe code) **My recommendation:** avoid 32-bit machines and use LMDB as much as possible. **Converting databases** is actually quite easy. For example from Sled to LMDB: ```bash cd src/db cargo run --features cli --bin convert -- -i path/to/garage/meta/db -a sled -o path/to/garage/meta/db.lmdb -b lmdb ``` Then, just add this to your `config.toml`: ```toml db_engine = "lmdb" ``` Co-authored-by: Alex Auvolat <alex@adnab.me> Reviewed-on: https://git.deuxfleurs.fr/Deuxfleurs/garage/pulls/322 Co-authored-by: Alex <alex@adnab.me> Co-committed-by: Alex <alex@adnab.me>
2022-06-08 08:01:44 +00:00
let db = lmdb_adapter::heed::EnvOpenOptions::new()
.max_dbs(100)
.map_size(map_size)
.open(&path)
.unwrap();
Ok(lmdb_adapter::LmdbDb::init(db))
}
e => Err(Error(format!("Invalid DB engine: {}", e).into())),
}
}