Immediately unref() maxLifetimeSeconds Timeout object to prevent blocking allowExitOnIdle (#2721)

Author: ChrisWritable

packages/pg-pool/index.js

@@ -252,7 +252,7 @@ class Pool extends EventEmitter {
         this.log('new client connected')
 
         if (this.options.maxLifetimeSeconds !== 0) {
-          setTimeout(() => {
+          const maxLifetimeTimeout = setTimeout(() => {
             this.log('ending client due to expired lifetime')
             this._expired.add(client)
             const idleIndex = this._idle.findIndex((idleItem) => idleItem.client === client)
@@ -265,6 +265,9 @@ class Pool extends EventEmitter {
               )
             }
           }, this.options.maxLifetimeSeconds * 1000)
+
+          maxLifetimeTimeout.unref()
+          client.once('end', () => clearTimeout(maxLifetimeTimeout))
         }
 
         return this._acquireClient(client, pendingItem, idleListener, true)

packages/pg-pool/test/idle-timeout-exit.js

@@ -3,7 +3,7 @@ if (module === require.main) {
   const allowExitOnIdle = process.env.ALLOW_EXIT_ON_IDLE === '1'
   const Pool = require('../index')
 
-  const pool = new Pool({ idleTimeoutMillis: 200, ...(allowExitOnIdle ? { allowExitOnIdle: true } : {}) })
+  const pool = new Pool({ maxLifetimeSeconds: 2, idleTimeoutMillis: 200, ...(allowExitOnIdle ? { allowExitOnIdle: true } : {}) })
   pool.query('SELECT NOW()', (err, res) => console.log('completed first'))
   pool.on('remove', () => {
     console.log('removed')