diff --git a/Cargo.toml b/Cargo.toml
index a71366f..266d8f1 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "tun2proxy"
-version = "0.5.1"
+version = "0.5.4"
 edition = "2021"
 license = "MIT"
 repository = "https://github.com/tun2proxy/tun2proxy"
diff --git a/src/args.rs b/src/args.rs
index 16ed744..ec839fb 100644
--- a/src/args.rs
+++ b/src/args.rs
@@ -107,6 +107,14 @@ pub struct Args {
     /// Daemonize for unix family or run as Windows service
     #[arg(long)]
     pub daemonize: bool,
+
+    /// Exit immediately when fatal error occurs, useful for running as a service
+    #[arg(long)]
+    pub exit_on_fatal_error: bool,
+
+    /// Maximum number of sessions to be handled concurrently
+    #[arg(long, value_name = "number", default_value = "200")]
+    pub max_sessions: usize,
 }
 
 fn validate_tun(p: &str) -> Result<String> {
@@ -149,6 +157,8 @@ impl Default for Args {
             verbosity: ArgVerbosity::Info,
             virtual_dns_pool: IpCidr::from_str("198.18.0.0/15").unwrap(),
             daemonize: false,
+            exit_on_fatal_error: false,
+            max_sessions: 200,
         }
     }
 }
diff --git a/src/bin/main.rs b/src/bin/main.rs
index 4b93d37..e39b7b4 100644
--- a/src/bin/main.rs
+++ b/src/bin/main.rs
@@ -1,7 +1,6 @@
 use tun2proxy::{Args, BoxError};
 
-#[tokio::main]
-async fn main() -> Result<(), BoxError> {
+fn main() -> Result<(), BoxError> {
     dotenvy::dotenv().ok();
     let args = Args::parse_args();
 
@@ -24,11 +23,16 @@ async fn main() -> Result<(), BoxError> {
         return Ok(());
     }
 
+    let rt = tokio::runtime::Builder::new_multi_thread().enable_all().build()?;
+    rt.block_on(main_async(args))
+}
+
+async fn main_async(args: Args) -> Result<(), BoxError> {
     let default = format!("{:?},hickory_proto=warn", args.verbosity);
     env_logger::Builder::from_env(env_logger::Env::default().default_filter_or(default)).init();
 
     let shutdown_token = tokio_util::sync::CancellationToken::new();
-    let join_handle = tokio::spawn({
+    let main_loop_handle = tokio::spawn({
         let shutdown_token = shutdown_token.clone();
         async move {
             #[cfg(target_os = "linux")]
@@ -51,14 +55,20 @@ async fn main() -> Result<(), BoxError> {
         }
     });
 
-    ctrlc2::set_async_handler(async move {
+    let ctrlc_fired = std::sync::Arc::new(std::sync::atomic::AtomicBool::new(false));
+    let ctrlc_fired_clone = ctrlc_fired.clone();
+    let ctrlc_handel = ctrlc2::set_async_handler(async move {
         log::info!("Ctrl-C received, exiting...");
+        ctrlc_fired_clone.store(true, std::sync::atomic::Ordering::SeqCst);
         shutdown_token.cancel();
     })
     .await;
 
-    if let Err(err) = join_handle.await {
-        log::error!("main_entry error {}", err);
+    main_loop_handle.await?;
+
+    if ctrlc_fired.load(std::sync::atomic::Ordering::SeqCst) {
+        log::info!("Ctrl-C fired, waiting the handler to finish...");
+        ctrlc_handel.await.map_err(|err| err.to_string())?;
     }
 
     Ok(())
diff --git a/src/lib.rs b/src/lib.rs
index bdaf83c..2659896 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -68,8 +68,6 @@ pub mod win_svc;
 
 const DNS_PORT: u16 = 53;
 
-const MAX_SESSIONS: u64 = 200;
-
 static TASK_COUNT: std::sync::atomic::AtomicU64 = std::sync::atomic::AtomicU64::new(0);
 use std::sync::atomic::Ordering::Relaxed;
 
@@ -260,10 +258,15 @@ where
                 ip_stack_stream?
             }
         };
+        let max_sessions = args.max_sessions as u64;
         match ip_stack_stream {
             IpStackStream::Tcp(tcp) => {
-                if TASK_COUNT.load(Relaxed) > MAX_SESSIONS {
-                    log::warn!("Too many sessions that over {MAX_SESSIONS}, dropping new session");
+                if TASK_COUNT.load(Relaxed) > max_sessions {
+                    if args.exit_on_fatal_error {
+                        log::info!("Too many sessions that over {max_sessions}, exiting...");
+                        break;
+                    }
+                    log::warn!("Too many sessions that over {max_sessions}, dropping new session");
                     continue;
                 }
                 log::trace!("Session count {}", TASK_COUNT.fetch_add(1, Relaxed) + 1);
@@ -286,8 +289,12 @@ where
                 });
             }
             IpStackStream::Udp(udp) => {
-                if TASK_COUNT.load(Relaxed) > MAX_SESSIONS {
-                    log::warn!("Too many sessions that over {MAX_SESSIONS}, dropping new session");
+                if TASK_COUNT.load(Relaxed) > max_sessions {
+                    if args.exit_on_fatal_error {
+                        log::info!("Too many sessions that over {max_sessions}, exiting...");
+                        break;
+                    }
+                    log::warn!("Too many sessions that over {max_sessions}, dropping new session");
                     continue;
                 }
                 log::trace!("Session count {}", TASK_COUNT.fetch_add(1, Relaxed) + 1);