commit f1206e76f2b94a6ef0833c5b7d278418705e470c
parent af453548ee60f060c49902a9fe83ea94566e1d70
Author: Greg Heartsfield <scsibug@imap.cc>
Date: Tue, 25 Jan 2022 20:39:24 -0600
feat: database reader connection pooling
Added connection pooling for queries, as well as basic configuration
options for min/max connections.
Diffstat:
6 files changed, 95 insertions(+), 15 deletions(-)
diff --git a/Cargo.lock b/Cargo.lock
@@ -662,6 +662,8 @@ dependencies = [
"lazy_static",
"log",
"nonzero_ext",
+ "r2d2",
+ "r2d2_sqlite",
"rusqlite",
"secp256k1",
"serde 1.0.131",
@@ -812,6 +814,27 @@ dependencies = [
]
[[package]]
+name = "r2d2"
+version = "0.8.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "545c5bc2b880973c9c10e4067418407a0ccaa3091781d1671d46eb35107cb26f"
+dependencies = [
+ "log",
+ "parking_lot",
+ "scheduled-thread-pool",
+]
+
+[[package]]
+name = "r2d2_sqlite"
+version = "0.19.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "54ca3c9468a76fc2ad724c486a59682fc362efeac7b18d1c012958bc19f34800"
+dependencies = [
+ "r2d2",
+ "rusqlite",
+]
+
+[[package]]
name = "rand"
version = "0.6.5"
source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -1029,6 +1052,15 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "254df5081ce98661a883445175e52efe99d1cb2a5552891d965d2f5d0cad1c16"
[[package]]
+name = "scheduled-thread-pool"
+version = "0.2.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dc6f74fd1204073fa02d5d5d68bec8021be4c38690b61264b2fdb48083d0e7d7"
+dependencies = [
+ "parking_lot",
+]
+
+[[package]]
name = "scopeguard"
version = "1.1.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
diff --git a/Cargo.toml b/Cargo.toml
@@ -20,6 +20,8 @@ serde = { version = "^1.0", features = ["derive"] }
serde_json = {version = "^1.0", features = ["preserve_order"]}
hex = "^0.4"
rusqlite = { version = "^0.26", features = ["limits"]}
+r2d2 = "^0.8"
+r2d2_sqlite = "^0.19"
lazy_static = "^1.4"
governor = "^0.4"
nonzero_ext = "^0.3"
diff --git a/config.toml b/config.toml
@@ -22,9 +22,18 @@ description = "A newly created nostr-rs-relay.\n\nCustomize this with your own i
# line option.
data_directory = "."
+# Database connection pool settings:
+
+# Minimum number of SQLite reader connections
+#min_conn = 4
+
+# Maximum number of SQLite reader connections
+#max_conn = 128
+
[network]
# Bind to this network address
address = "0.0.0.0"
+
# Listen on this port
port = 8080
@@ -37,22 +46,22 @@ reject_future_seconds = 1800
[limits]
# Limit events created per second, averaged over one minute. Must be
# an integer. If not set (or set to 0), defaults to unlimited.
-messages_per_sec = 0
+#messages_per_sec = 0
# Limit the maximum size of an EVENT message. Defaults to 128 KB.
# Set to 0 for unlimited.
-max_event_bytes = 131072
+#max_event_bytes = 131072
# Maximum WebSocket message in bytes. Defaults to 128 KB.
-max_ws_message_bytes = 131072
+#max_ws_message_bytes = 131072
# Maximum WebSocket frame size in bytes. Defaults to 128 KB.
-max_ws_frame_bytes = 131072
+#max_ws_frame_bytes = 131072
# Broadcast buffer size, in number of events. This prevents slow
# readers from consuming memory. Defaults to 4096.
-broadcast_buffer = 4096
+#broadcast_buffer = 4096
# Event persistence buffer size, in number of events. This provides
# backpressure to senders if writes are slow. Defaults to 16.
-event_persist_buffer = 16
+#event_persist_buffer = 16
diff --git a/src/config.rs b/src/config.rs
@@ -22,6 +22,8 @@ pub struct Info {
#[allow(unused)]
pub struct Database {
pub data_directory: String,
+ pub min_conn: u32,
+ pub max_conn: u32,
}
#[derive(Debug, Serialize, Deserialize)]
@@ -93,6 +95,13 @@ impl Settings {
// override with file contents
.with_merged(config::File::with_name("config"))?
.try_into()?;
+ // ensure connection pool size is logical
+ if settings.database.min_conn > settings.database.max_conn {
+ panic!(
+ "Database min_conn setting ({}) cannot exceed max_conn ({})",
+ settings.database.min_conn, settings.database.max_conn
+ );
+ }
Ok(settings)
}
}
@@ -109,6 +118,8 @@ impl Default for Settings {
},
database: Database {
data_directory: ".".to_owned(),
+ min_conn: 4,
+ max_conn: 128,
},
network: Network {
port: 8080,
diff --git a/src/db.rs b/src/db.rs
@@ -1,4 +1,5 @@
//! Event persistence and querying
+use crate::config;
use crate::error::Result;
use crate::event::Event;
use crate::subscription::Subscription;
@@ -11,6 +12,8 @@ use rusqlite::Connection;
use rusqlite::OpenFlags;
//use std::num::NonZeroU32;
use crate::config::SETTINGS;
+use r2d2;
+use r2d2_sqlite::SqliteConnectionManager;
use rusqlite::limits::Limit;
use rusqlite::types::ToSql;
use std::path::Path;
@@ -18,6 +21,8 @@ use std::thread;
use std::time::Instant;
use tokio::task;
+pub type SqlitePool = r2d2::Pool<r2d2_sqlite::SqliteConnectionManager>;
+
/// Database file
const DB_FILE: &str = "nostr.db";
@@ -94,6 +99,23 @@ FOREIGN KEY(event_id) REFERENCES event(id) ON UPDATE RESTRICT ON DELETE CASCADE
CREATE INDEX IF NOT EXISTS pubkey_ref_index ON pubkey_ref(referenced_pubkey);
"##;
+pub fn build_read_pool() -> SqlitePool {
+ info!("Build a connection pool");
+ let config = config::SETTINGS.read().unwrap();
+ let db_dir = &config.database.data_directory;
+ let full_path = Path::new(db_dir).join(DB_FILE);
+ let manager = SqliteConnectionManager::file(&full_path)
+ .with_flags(OpenFlags::SQLITE_OPEN_READ_ONLY)
+ .with_init(|c| c.execute_batch(STARTUP_SQL));
+ let pool: SqlitePool = r2d2::Pool::builder()
+ .test_on_check_out(true) // no noticeable performance hit
+ .min_idle(Some(config.database.min_conn))
+ .max_size(config.database.max_conn)
+ .build(manager)
+ .unwrap();
+ return pool;
+}
+
/// Upgrade DB to latest version, and execute pragma settings
pub fn upgrade_db(conn: &mut Connection) -> Result<()> {
// check the version.
@@ -615,22 +637,17 @@ fn query_from_sub(sub: &Subscription) -> (String, Vec<Box<dyn ToSql>>) {
/// query is immediately aborted.
pub async fn db_query(
sub: Subscription,
+ conn: r2d2::PooledConnection<r2d2_sqlite::SqliteConnectionManager>,
query_tx: tokio::sync::mpsc::Sender<QueryResult>,
mut abandon_query_rx: tokio::sync::oneshot::Receiver<()>,
) {
task::spawn_blocking(move || {
- let config = SETTINGS.read().unwrap();
- let db_dir = &config.database.data_directory;
- let full_path = Path::new(db_dir).join(DB_FILE);
-
- let conn = Connection::open_with_flags(&full_path, OpenFlags::SQLITE_OPEN_READ_ONLY)?;
- debug!("opened database for reading");
debug!("going to query for: {:?}", sub);
let mut row_count: usize = 0;
let start = Instant::now();
// generate SQL query
let (q, p) = query_from_sub(&sub);
- // execute the query
+ // execute the query. Don't cache, since queries vary so much.
let mut stmt = conn.prepare(&q)?;
let mut event_rows = stmt.query(rusqlite::params_from_iter(p))?;
while let Some(row) = event_rows.next()? {
diff --git a/src/main.rs b/src/main.rs
@@ -43,6 +43,7 @@ fn db_from_args(args: Vec<String>) -> Option<String> {
/// Handle arbitrary HTTP requests, including for WebSocket upgrades.
async fn handle_web_request(
mut request: Request<Body>,
+ pool: db::SqlitePool,
remote_addr: SocketAddr,
broadcast: Sender<Event>,
event_tx: tokio::sync::mpsc::Sender<Event>,
@@ -83,8 +84,9 @@ async fn handle_web_request(
Some(config),
)
.await;
+
tokio::spawn(nostr_server(
- ws_stream, broadcast, event_tx, shutdown,
+ pool, ws_stream, broadcast, event_tx, shutdown,
));
}
Err(e) => println!(
@@ -188,6 +190,8 @@ fn main() -> Result<(), Error> {
rt.block_on(async {
let settings = config::SETTINGS.read().unwrap();
info!("listening on: {}", socket_addr);
+ // build a connection pool for sqlite connections
+ let pool = db::build_read_pool();
// all client-submitted valid events are broadcast to every
// other client on this channel. This should be large enough
// to accomodate slower readers (messages are dropped if
@@ -214,6 +218,7 @@ fn main() -> Result<(), Error> {
// A `Service` is needed for every connection, so this
// creates one from our `handle_request` function.
let make_svc = make_service_fn(|conn: &AddrStream| {
+ let svc_pool = pool.clone();
let remote_addr = conn.remote_addr();
let bcast = bcast_tx.clone();
let event = event_tx.clone();
@@ -223,6 +228,7 @@ fn main() -> Result<(), Error> {
Ok::<_, Infallible>(service_fn(move |request: Request<Body>| {
handle_web_request(
request,
+ svc_pool.clone(),
remote_addr,
bcast.clone(),
event.clone(),
@@ -246,6 +252,7 @@ fn main() -> Result<(), Error> {
/// Handle new client connections. This runs through an event loop
/// for all client communication.
async fn nostr_server(
+ pool: db::SqlitePool,
ws_stream: WebSocketStream<Upgraded>,
broadcast: Sender<Event>,
event_tx: tokio::sync::mpsc::Sender<Event>,
@@ -337,7 +344,9 @@ async fn nostr_server(
Ok(()) => {
running_queries.insert(s.id.to_owned(), abandon_query_tx);
// start a database query
- db::db_query(s, query_tx.clone(), abandon_query_rx).await;
+ // show pool stats
+ debug!("DB pool stats: {:?}", pool.state());
+ db::db_query(s, pool.get().expect("could not get connection"), query_tx.clone(), abandon_query_rx).await;
},
Err(e) => {
info!("Subscription error: {}", e);
