change the default number of connections to 3 for workers

README.md

@@ -299,6 +299,7 @@ upcoming CLI tool.
 | PIP_TRUSTED_HOST          | None                   | The trusted host to pass to pip.                                                                                                                                                                   | Worker                |
 | PATH                      | None                   | The path environment variable, usually inherited                                                                                                                                                   | Worker                |
 | HOME                      | None                   | The home directory to use for Go and Bash , usually inherited                                                                                                                                      | Worker                |
+| DATABASE_CONNECTIONS      | 50 (Server)/3 (Worker) | The max number of connections in the database connection pool                                                                                                                                      | All                   |
 
 ## Run a local dev setup
 

backend/src/main.rs

@@ -21,8 +21,6 @@ async fn main() -> anyhow::Result<()> {
 
     windmill_common::tracing_init::initialize_tracing();
 
-    let db = windmill_common::connect_db().await?;
-
     let num_workers = std::env::var("NUM_WORKERS")
         .ok()
         .and_then(|x| x.parse::<i32>().ok())
@@ -43,6 +41,8 @@ async fn main() -> anyhow::Result<()> {
         .and_then(|x| x.parse::<bool>().ok())
         .unwrap_or(false);
 
+    let db = windmill_common::connect_db(server_mode).await?;
+
     if server_mode {
         windmill_api::migrate_db(&db).await?;
     }

backend/windmill-api/src/main.rs

@@ -14,7 +14,7 @@ use anyhow::Ok;
 async fn main() -> anyhow::Result<()> {
     windmill_common::tracing_init::initialize_tracing();
 
-    let db = windmill_common::connect_db().await?;
+    let db = windmill_common::connect_db(true).await?;
 
     let num_workers = std::env::var("NUM_WORKERS")
         .ok()

backend/windmill-common/src/lib.rs

@@ -29,7 +29,8 @@ pub mod tracing_init;
 pub const DEFAULT_NUM_WORKERS: usize = 3;
 pub const DEFAULT_TIMEOUT: i32 = 300;
 pub const DEFAULT_SLEEP_QUEUE: u64 = 50;
-pub const DEFAULT_MAX_CONNECTIONS: u32 = 100;
+pub const DEFAULT_MAX_CONNECTIONS_SERVER: u32 = 50;
+pub const DEFAULT_MAX_CONNECTIONS_WORKER: u32 = 3;
 
 #[cfg(feature = "tokio")]
 pub async fn shutdown_signal(tx: tokio::sync::broadcast::Sender<()>) -> anyhow::Result<()> {
@@ -79,7 +80,7 @@ async fn metrics() -> Result<String, Error> {
 }
 
 #[cfg(feature = "sqlx")]
-pub async fn connect_db() -> anyhow::Result<sqlx::Pool<sqlx::Postgres>> {
+pub async fn connect_db(server_mode: bool) -> anyhow::Result<sqlx::Pool<sqlx::Postgres>> {
     use anyhow::Context;
 
     let database_url = std::env::var("DATABASE_URL")
@@ -87,7 +88,13 @@ pub async fn connect_db() -> anyhow::Result<sqlx::Pool<sqlx::Postgres>> {
 
     let max_connections = match std::env::var("DATABASE_CONNECTIONS") {
         Ok(n) => n.parse::<u32>().context("invalid DATABASE_CONNECTIONS")?,
-        Err(_) => DEFAULT_MAX_CONNECTIONS,
+        Err(_) => {
+            if server_mode {
+                DEFAULT_MAX_CONNECTIONS_SERVER
+            } else {
+                DEFAULT_MAX_CONNECTIONS_WORKER
+            }
+        }
     };
 
     Ok(connect(&database_url, max_connections).await?)
@@ -101,6 +108,7 @@ pub async fn connect(
     use std::time::Duration;
 
     sqlx::postgres::PgPoolOptions::new()
+        .min_connections(3)
         .max_connections(max_connections)
         .max_lifetime(Duration::from_secs(30 * 60)) // 30 mins
         .connect(database_url)