diff --git a/examples/mratls_grpcs_server.rs b/examples/mratls_grpcs_server.rs
index e922239..b7d377c 100644
--- a/examples/mratls_grpcs_server.rs
+++ b/examples/mratls_grpcs_server.rs
@@ -22,6 +22,9 @@ use tower::ServiceExt;
 use occlum_ratls::prelude::*;
 use occlum_ratls::RaTlsConfigBuilder;
 
+use std::sync::atomic::{AtomicUsize, Ordering};
+static COUNTER: AtomicUsize = AtomicUsize::new(0);
+
 #[tokio::main]
 async fn main() -> Result<(), Box<dyn std::error::Error>> {
     env_logger::init_from_env(env_logger::Env::default().default_filter_or("trace"));
@@ -38,10 +41,6 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
         .map_err(|e| std::io::Error::new(std::io::ErrorKind::Other, format!("{}", e)))?;
     tls.alpn_protocols = vec![b"h2".to_vec()];
 
-    // create and write a file on the disk
-    let mut file = std::fs::File::create("test.txt")?;
-    file.write_all(b"Hello, world!")?;
-
     let server = EchoServer::default();
 
     let svc = Routes::new(pb::echo_server::EchoServer::new(server)).prepare();
@@ -115,6 +114,11 @@ impl pb::echo_server::Echo for EchoServer {
             conn_info.addr, conn_info.certificates
         );
 
+        let count = COUNTER.fetch_add(1, Ordering::SeqCst);
+        let mut file = std::fs::File::create(format!("test{count}.txt"))?;
+        let content = format!("Hello, world! {count}");
+        file.write_all(content.as_bytes())?;
+
         let message = request.into_inner().message;
         Ok(Response::new(EchoResponse { message }))
     }