garage/src/model/garage.rs
Alex b44d3fc796 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: Deuxfleurs/garage#322
Co-authored-by: Alex <alex@adnab.me>
Co-committed-by: Alex <alex@adnab.me>
2022-06-08 10:01:44 +02:00

228 lines
5.9 KiB
Rust

use std::sync::Arc;
use netapp::NetworkKey;
use garage_db as db;
use garage_util::background::*;
use garage_util::config::*;
use garage_rpc::system::System;
use garage_block::manager::*;
use garage_table::replication::ReplicationMode;
use garage_table::replication::TableFullReplication;
use garage_table::replication::TableShardedReplication;
use garage_table::*;
use crate::s3::block_ref_table::*;
use crate::s3::object_table::*;
use crate::s3::version_table::*;
use crate::bucket_alias_table::*;
use crate::bucket_table::*;
use crate::helper;
use crate::key_table::*;
#[cfg(feature = "k2v")]
use crate::index_counter::*;
#[cfg(feature = "k2v")]
use crate::k2v::{counter_table::*, item_table::*, poll::*, rpc::*};
/// An entire Garage full of data
pub struct Garage {
/// The parsed configuration Garage is running
pub config: Config,
/// The local database
pub db: db::Db,
/// A background job runner
pub background: Arc<BackgroundRunner>,
/// The membership manager
pub system: Arc<System>,
/// The block manager
pub block_manager: Arc<BlockManager>,
/// Table containing buckets
pub bucket_table: Arc<Table<BucketTable, TableFullReplication>>,
/// Table containing bucket aliases
pub bucket_alias_table: Arc<Table<BucketAliasTable, TableFullReplication>>,
/// Table containing api keys
pub key_table: Arc<Table<KeyTable, TableFullReplication>>,
/// Table containing S3 objects
pub object_table: Arc<Table<ObjectTable, TableShardedReplication>>,
/// Table containing S3 object versions
pub version_table: Arc<Table<VersionTable, TableShardedReplication>>,
/// Table containing S3 block references (not blocks themselves)
pub block_ref_table: Arc<Table<BlockRefTable, TableShardedReplication>>,
#[cfg(feature = "k2v")]
pub k2v: GarageK2V,
}
#[cfg(feature = "k2v")]
pub struct GarageK2V {
/// Table containing K2V items
pub item_table: Arc<Table<K2VItemTable, TableShardedReplication>>,
/// Indexing table containing K2V item counters
pub counter_table: Arc<IndexCounter<K2VCounterTable>>,
/// K2V RPC handler
pub rpc: Arc<K2VRpcHandler>,
}
impl Garage {
/// Create and run garage
pub fn new(config: Config, db: db::Db, background: Arc<BackgroundRunner>) -> Arc<Self> {
let network_key = NetworkKey::from_slice(
&hex::decode(&config.rpc_secret).expect("Invalid RPC secret key")[..],
)
.expect("Invalid RPC secret key");
let replication_mode = ReplicationMode::parse(&config.replication_mode)
.expect("Invalid replication_mode in config file.");
info!("Initialize membership management system...");
let system = System::new(
network_key,
background.clone(),
replication_mode.replication_factor(),
&config,
);
let data_rep_param = TableShardedReplication {
system: system.clone(),
replication_factor: replication_mode.replication_factor(),
write_quorum: replication_mode.write_quorum(),
read_quorum: 1,
};
let meta_rep_param = TableShardedReplication {
system: system.clone(),
replication_factor: replication_mode.replication_factor(),
write_quorum: replication_mode.write_quorum(),
read_quorum: replication_mode.read_quorum(),
};
let control_rep_param = TableFullReplication {
system: system.clone(),
max_faults: replication_mode.control_write_max_faults(),
};
info!("Initialize block manager...");
let block_manager = BlockManager::new(
&db,
config.data_dir.clone(),
config.compression_level,
config.block_manager_background_tranquility,
data_rep_param,
system.clone(),
);
// ---- admin tables ----
info!("Initialize bucket_table...");
let bucket_table = Table::new(BucketTable, control_rep_param.clone(), system.clone(), &db);
info!("Initialize bucket_alias_table...");
let bucket_alias_table = Table::new(
BucketAliasTable,
control_rep_param.clone(),
system.clone(),
&db,
);
info!("Initialize key_table_table...");
let key_table = Table::new(KeyTable, control_rep_param, system.clone(), &db);
// ---- S3 tables ----
info!("Initialize block_ref_table...");
let block_ref_table = Table::new(
BlockRefTable {
block_manager: block_manager.clone(),
},
meta_rep_param.clone(),
system.clone(),
&db,
);
info!("Initialize version_table...");
let version_table = Table::new(
VersionTable {
background: background.clone(),
block_ref_table: block_ref_table.clone(),
},
meta_rep_param.clone(),
system.clone(),
&db,
);
info!("Initialize object_table...");
#[allow(clippy::redundant_clone)]
let object_table = Table::new(
ObjectTable {
background: background.clone(),
version_table: version_table.clone(),
},
meta_rep_param.clone(),
system.clone(),
&db,
);
// ---- K2V ----
#[cfg(feature = "k2v")]
let k2v = GarageK2V::new(system.clone(), &db, meta_rep_param);
info!("Initialize Garage...");
Arc::new(Self {
config,
db,
background,
system,
block_manager,
bucket_table,
bucket_alias_table,
key_table,
object_table,
version_table,
block_ref_table,
#[cfg(feature = "k2v")]
k2v,
})
}
pub fn bucket_helper(&self) -> helper::bucket::BucketHelper {
helper::bucket::BucketHelper(self)
}
pub fn key_helper(&self) -> helper::key::KeyHelper {
helper::key::KeyHelper(self)
}
}
#[cfg(feature = "k2v")]
impl GarageK2V {
fn new(system: Arc<System>, db: &db::Db, meta_rep_param: TableShardedReplication) -> Self {
info!("Initialize K2V counter table...");
let counter_table = IndexCounter::new(system.clone(), meta_rep_param.clone(), db);
info!("Initialize K2V subscription manager...");
let subscriptions = Arc::new(SubscriptionManager::new());
info!("Initialize K2V item table...");
let item_table = Table::new(
K2VItemTable {
counter_table: counter_table.clone(),
subscriptions: subscriptions.clone(),
},
meta_rep_param,
system.clone(),
db,
);
let rpc = K2VRpcHandler::new(system, item_table.clone(), subscriptions);
Self {
item_table,
counter_table,
rpc,
}
}
}