stats: Decrease cl_idle when idle socket disconnects

Author: magec

src/client.rs

@@ -135,6 +135,10 @@ pub async fn client_entrypoint(
 
                         if !client.is_admin() {
                             let _ = drain.send(-1).await;
+
+			    if result.is_err() {
+				client.stats.disconnect();
+			    }
                         }
 
                         result
@@ -183,6 +187,10 @@ pub async fn client_entrypoint(
 
                                 if !client.is_admin() {
                                     let _ = drain.send(-1).await;
+
+				    if result.is_err() {
+					client.stats.disconnect();
+				    }
                                 }
 
                                 result
@@ -233,8 +241,13 @@ pub async fn client_entrypoint(
 
                     if !client.is_admin() {
                         let _ = drain.send(-1).await;
+
+			if result.is_err() {
+			    client.stats.disconnect();
+			}
                     }
 
+
                     result
                 }
                 Err(err) => Err(err),
@@ -258,9 +271,12 @@ pub async fn client_entrypoint(
 
                     if !client.is_admin() {
                         let _ = drain.send(-1).await;
-                    }
 
-                    result
+			if result.is_err() {
+			    client.stats.disconnect();
+			}
+                    }
+		    result
                 }
 
                 Err(err) => Err(err),

tests/ruby/admin_spec.rb

@@ -179,7 +179,7 @@
     context "clients connects and disconnect normally" do
       let(:processes) { Helpers::Pgcat.single_instance_setup("sharded_db", 2) }
 
-      it 'shows the number same number of clients before and after' do
+      it 'shows the same number of clients before and after' do
         clients_before = clients_connected_to_pool(processes: processes)
         threads = []
         connections = Array.new(4) { PG::connect("#{pgcat_conn_str}?application_name=one_query") }
@@ -194,6 +194,29 @@
       end
     end
 
+    context "clients connects and disconnect abruptly" do
+      let(:processes) { Helpers::Pgcat.single_instance_setup("sharded_db", 10) }
+
+      it 'shows the same number of clients before and after' do
+        threads = []
+        connections = Array.new(2) { PG::connect("#{pgcat_conn_str}?application_name=one_query") }
+        connections.each do |c|
+          threads << Thread.new { c.async_exec("SELECT 1") }
+        end
+        clients_before = clients_connected_to_pool(processes: processes)
+        random_string = (0...8).map { (65 + rand(26)).chr }.join
+        connection_string = "#{pgcat_conn_str}?application_name=#{random_string}"
+        faulty_client = Process.spawn("psql -Atx #{connection_string} >/dev/null")
+        sleep(1)
+        # psql starts two processes, we only know the pid of the parent, this
+        # ensure both are killed
+        `pkill -9 -f '#{random_string}'`
+        Process.wait(faulty_client)
+        clients_after = clients_connected_to_pool(processes: processes)
+        expect(clients_before).to eq(clients_after)
+      end
+    end
+
     context "clients overwhelm server pools" do
       let(:processes) { Helpers::Pgcat.single_instance_setup("sharded_db", 2) }