A little cleanup

src/main.rs

@@ -15,8 +15,6 @@
 // specific language governing permissions and limitations
 // under the License.
 
-use std::net::SocketAddr;
-
 use clap::Parser;
 use color_eyre::Result;
 use dft::args::DftArgs;
@@ -30,7 +28,6 @@ use dft::telemetry;
 use dft::tui::state::AppState;
 use dft::tui::{state, App};
 use log::info;
-use metrics_exporter_prometheus::PrometheusBuilder;
 
 #[allow(unused_mut)]
 fn main() -> Result<()> {
@@ -67,22 +64,13 @@ async fn app_entry_point(cli: DftArgs, state: AppState<'_>) -> Result<()> {
             execution_ctx.execute_ddl().await;
         }
         let app_execution = AppExecution::new(execution_ctx);
-        let app = FlightSqlApp::new(
+        let app = FlightSqlApp::try_new(
             app_execution,
             &cli.flightsql_host
                 .unwrap_or(DEFAULT_SERVER_ADDRESS.to_string()),
+            &state.config.flightsql.server_metrics_port,
         )
-        .await;
-        #[cfg(feature = "metrics")]
-        {
-            let builder = PrometheusBuilder::new();
-            let addr: SocketAddr = state.config.flightsql.server_metrics_port.parse()?;
-            info!("Listening to metrics on {addr}");
-            builder
-                .with_http_listener(addr)
-                .install()
-                .expect("failed to install metrics recorder/exporter");
-        }
+        .await?;
         app.run_app().await;
         return Ok(());
     }

src/server/mod.rs

@@ -19,6 +19,9 @@ pub mod services;
 
 use crate::execution::AppExecution;
 use crate::test_utils::trailers_layer::TrailersLayer;
+use color_eyre::Result;
+use log::info;
+use metrics_exporter_prometheus::PrometheusBuilder;
 use std::net::SocketAddr;
 use std::time::Duration;
 use tokio::net::TcpListener;
@@ -41,7 +44,11 @@ pub struct FlightSqlApp {
 impl FlightSqlApp {
     /// create a new app for the flightsql server
     #[allow(dead_code)]
-    pub async fn new(app_execution: AppExecution, addr: &str) -> Self {
+    pub async fn try_new(
+        app_execution: AppExecution,
+        addr: &str,
+        metrics_addr: &str,
+    ) -> Result<Self> {
         let flightsql = services::flightsql::FlightSqlServiceImpl::new(app_execution);
         // let OS choose a free port
         let listener = TcpListener::bind(addr).await.unwrap();
@@ -65,14 +72,32 @@ impl FlightSqlApp {
                 shutdown_future,
             );
 
+        #[cfg(feature = "metrics")]
+        {
+            let builder = PrometheusBuilder::new();
+            let addr: SocketAddr = metrics_addr.parse()?;
+            info!("Listening to metrics on {addr}");
+            builder
+                .with_http_listener(addr)
+                .install()
+                .expect("failed to install metrics recorder/exporter");
+
+            metrics::describe_histogram!(
+                "logical_planning_ms",
+                metrics::Unit::Milliseconds,
+                "Logical planning ms"
+            );
+        }
+
         // Run the server in its own background task
         let handle = tokio::task::spawn(serve_future);
 
-        Self {
+        let app = Self {
             shutdown: Some(tx),
             addr,
             handle: Some(handle),
-        }
+        };
+        Ok(app)
     }
 
     /// Stops the server and waits for the server to shutdown