diff --git a/.github/workflows/audit.yaml b/.github/workflows/audit.yaml
index 434e2ce..7976371 100644
--- a/.github/workflows/audit.yaml
+++ b/.github/workflows/audit.yaml
@@ -17,7 +17,7 @@ jobs:
   security_audit:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: taiki-e/install-action@cargo-deny
       - name: Scan for vulnerabilities
         run: cargo deny check advisories
\ No newline at end of file
diff --git a/Cargo.lock b/Cargo.lock
index c6e6405..2e901e5 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1300,6 +1300,12 @@ dependencies = [
  "windows-sys 0.48.0",
 ]
 
+[[package]]
+name = "mutually_exclusive_features"
+version = "0.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6d02c0b00610773bb7fc61d85e13d86c7858cbdf00e1a120bfc41bc055dbaa0e"
+
 [[package]]
 name = "native-tls"
 version = "0.2.11"
@@ -2640,6 +2646,19 @@ dependencies = [
  "tracing-core",
 ]
 
+[[package]]
+name = "tracing-actix-web"
+version = "0.7.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fa069bd1503dd526ee793bb3fce408895136c95fc86d2edb2acf1c646d7f0684"
+dependencies = [
+ "actix-web",
+ "mutually_exclusive_features",
+ "pin-project",
+ "tracing",
+ "uuid",
+]
+
 [[package]]
 name = "tracing-attributes"
 version = "0.1.27"
@@ -3139,6 +3158,7 @@ dependencies = [
  "sqlx",
  "tokio",
  "tracing",
+ "tracing-actix-web",
  "tracing-bunyan-formatter",
  "tracing-log 0.2.0",
  "tracing-subscriber",
diff --git a/Cargo.toml b/Cargo.toml
index cfcbe8a..d1ed519 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -23,6 +23,7 @@ secrecy = { version = "0.8.0", features = ["serde"] }
 serde = { version = "1.0.197", features = ["derive"] }
 tokio = { version = "1.36.0", features = ["macros", "rt-multi-thread"] }
 tracing = { version = "0.1.40", features = ["log"] }
+tracing-actix-web = "0.7.10"
 tracing-bunyan-formatter = "0.3.9"
 tracing-log = "0.2.0"
 tracing-subscriber = { version = "0.3.18", features = ["registry", "env-filter"] }
diff --git a/README.md b/README.md
index de2eb95..20c507d 100644
--- a/README.md
+++ b/README.md
@@ -28,3 +28,5 @@ To disable a clippy warning: `#[allow(clippy::lint_name)]`
 ### Ch4
 
 - [ ] Understand all those tracing related crates (e.g., `tracing::instrument`).
+- [ ] Wire tracing with open telemetry (`tracing-opentelemetry`).
+- [ ] `tracing` v.s. `log`.
diff --git a/src/main.rs b/src/main.rs
index 85b9450..fa8fe7b 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -14,7 +14,7 @@ async fn main() -> Result<(), std::io::Error> {
     let address = format!("127.0.0.1:{}", configuration.application_port);
     let listener = TcpListener::bind(address)?;
     let connection_pool =
-        PgPool::connect(&configuration.database.connection_string().expose_secret())
+        PgPool::connect(configuration.database.connection_string().expose_secret())
             .await
             .expect("Failed to connect to Postgres.");
 
diff --git a/src/routes/subscriptions.rs b/src/routes/subscriptions.rs
index 3e06b6a..e9c8707 100644
--- a/src/routes/subscriptions.rs
+++ b/src/routes/subscriptions.rs
@@ -13,7 +13,6 @@ pub struct FormData {
     name = "Adding a new subscriber", // span message, fn name by default
     skip(form, db_pool), // skip these two fields in the span
     fields(
-        request_id = %Uuid::new_v4(),
         subscriber_email = %form.email,
         subscriber_name = %form.name
     )
diff --git a/src/startup.rs b/src/startup.rs
index 0f55f7e..a0f44ba 100644
--- a/src/startup.rs
+++ b/src/startup.rs
@@ -1,10 +1,10 @@
 use crate::routes::{health_check, subscribe};
 
 use actix_web::dev::Server;
-use actix_web::middleware::Logger;
 use actix_web::{web, App, HttpServer};
 use sqlx::PgPool;
 use std::net::TcpListener;
+use tracing_actix_web::TracingLogger;
 
 // `async` is no longer needed as we don't have .await calls.
 pub fn run(listener: TcpListener, db_pool: PgPool) -> Result<Server, std::io::Error> {
@@ -12,7 +12,7 @@ pub fn run(listener: TcpListener, db_pool: PgPool) -> Result<Server, std::io::Er
     let db_pool = web::Data::new(db_pool);
     let server = HttpServer::new(move || {
         App::new()
-            .wrap(Logger::default())
+            .wrap(TracingLogger::default())
             // .route("/", web::get().to(greet))
             // .route("/{name}", web::get().to(greet))
             .route("/health_check", web::get().to(health_check))
diff --git a/tests/health_check.rs b/tests/health_check.rs
index ac182fe..acff3ad 100644
--- a/tests/health_check.rs
+++ b/tests/health_check.rs
@@ -52,7 +52,7 @@ async fn spawn_app() -> TestApp {
 async fn configure_database(config: &DatabseSettings) -> PgPool {
     // Create database
     let mut connection =
-        PgConnection::connect(&config.connection_string_without_db().expose_secret())
+        PgConnection::connect(config.connection_string_without_db().expose_secret())
             .await
             .expect("Failed to connect to Postgres.");
 
@@ -62,7 +62,7 @@ async fn configure_database(config: &DatabseSettings) -> PgPool {
         .await
         .expect("Failed to create database.");
 
-    let connection_pool = PgPool::connect(&config.connection_string().expose_secret())
+    let connection_pool = PgPool::connect(config.connection_string().expose_secret())
         .await
         .expect("Failed to connect to Postgres.");