aboutsummaryrefslogtreecommitdiff
path: root/src/db/bin
diff options
context:
space:
mode:
authorAlex <alex@adnab.me>2022-06-08 10:01:44 +0200
committerAlex <alex@adnab.me>2022-06-08 10:01:44 +0200
commitb44d3fc796484a50cd6854f20c9b46e5fddedc9d (patch)
tree29f6da0e8dc68485edf713aaa7331536f4ff4fde /src/db/bin
parent7eed3ceda9cf964e3435f22fc1852e27f4f5a8ae (diff)
downloadgarage-b44d3fc796484a50cd6854f20c9b46e5fddedc9d.tar.gz
garage-b44d3fc796484a50cd6854f20c9b46e5fddedc9d.zip
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>
Diffstat (limited to 'src/db/bin')
-rw-r--r--src/db/bin/convert.rs76
1 files changed, 76 insertions, 0 deletions
diff --git a/src/db/bin/convert.rs b/src/db/bin/convert.rs
new file mode 100644
index 00000000..9e45e61f
--- /dev/null
+++ b/src/db/bin/convert.rs
@@ -0,0 +1,76 @@
+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())
+ })?;
+
+ let map_size = if u32::MAX as usize == usize::MAX {
+ eprintln!(
+ "LMDB is not recommended on 32-bit systems, database size will be limited"
+ );
+ 1usize << 30 // 1GB for 32-bit systems
+ } else {
+ 1usize << 40 // 1TB for 64-bit systems
+ };
+
+ 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())),
+ }
+}