Async Rust with Tokio: Building High-Performance Network Applications#

Asynchronous programming is essential for building scalable network applications, and Tokio is Rust’s most powerful async runtime. In this comprehensive guide, we’ll explore how to leverage Tokio to build high-performance servers, handle thousands of concurrent connections, and write efficient async code.

Understanding Async/Await in Rust#

Before diving into Tokio, let’s understand how async/await works in Rust.

The Basics#

1
// An async function returns a Future
2
async fn fetch_data() -> String {
3
    // Simulate async operation
4
    tokio::time::sleep(tokio::time::Duration::from_secs(1)).await;
5
    "Data fetched!".to_string()
6
}
7

8
// Async functions must be awaited
9
async fn process() {
10
    let data = fetch_data().await;
11
    println!("{}", data);
12
}

Key Concepts#

Futures: Async functions return Future types that represent values that will be available later
Polling: The runtime polls futures to check if they’re ready
Zero-cost abstractions: Async code compiles to efficient state machines

Getting Started with Tokio#

First, add Tokio to your Cargo.toml:

1
[dependencies]
2
tokio = { version = "1.43", features = ["full"] }

Basic Tokio Application#

1
use tokio::time::{sleep, Duration};
2

3
#[tokio::main]
4
async fn main() {
5
    println!("Starting async operations...");
6

7
    // Run multiple async operations concurrently
8
    let task1 = async {
9
        sleep(Duration::from_secs(2)).await;
10
        println!("Task 1 completed");
11
    };
12

13
    let task2 = async {
14
        sleep(Duration::from_secs(1)).await;
15
        println!("Task 2 completed");
16
    };
17

18
    // Join executes both futures concurrently
19
    tokio::join!(task1, task2);
20
    println!("All tasks completed!");
21
}

Building a TCP Echo Server#

Let’s build a production-ready TCP echo server that can handle thousands of concurrent connections.

Simple Echo Server#

1
use tokio::net::{TcpListener, TcpStream};
2
use tokio::io::{AsyncReadExt, AsyncWriteExt};
3
use std::error::Error;
4

5
async fn handle_connection(mut socket: TcpStream) -> Result<(), Box<dyn Error>> {
6
    let mut buffer = [0; 1024];
7

8
    loop {
9
        // Read data from the socket
10
        let n = socket.read(&mut buffer).await?;
11

12
        // If we read 0 bytes, the connection is closed
13
        if n == 0 {
14
            return Ok(());
15
        }
16

17
        // Echo the data back
18
        socket.write_all(&buffer[0..n]).await?;
19
        socket.flush().await?;
20
    }
21
}
22

23
#[tokio::main]
24
async fn main() -> Result<(), Box<dyn Error>> {
25
    let listener = TcpListener::bind("127.0.0.1:8080").await?;
26
    println!("Echo server listening on 127.0.0.1:8080");
27

28
    loop {
29
        let (socket, addr) = listener.accept().await?;
30
        println!("New connection from: {}", addr);
31

32
        // Spawn a new task for each connection
33
        tokio::spawn(async move {
34
            if let Err(e) = handle_connection(socket).await {
35
                eprintln!("Error handling connection: {}", e);
36
            }
37
        });
38
    }
39
}

Advanced Echo Server with Graceful Shutdown#

1
use tokio::net::{TcpListener, TcpStream};
2
use tokio::io::{AsyncReadExt, AsyncWriteExt};
3
use tokio::sync::broadcast;
4
use tokio::select;
5
use std::error::Error;
6
use std::sync::Arc;
7
use std::sync::atomic::{AtomicUsize, Ordering};
8

9
struct Server {
10
    listener: TcpListener,
11
    shutdown: broadcast::Sender<()>,
12
    connection_count: Arc<AtomicUsize>,
13
}
14

15
impl Server {
16
    async fn new(addr: &str) -> Result<Self, Box<dyn Error>> {
17
        let listener = TcpListener::bind(addr).await?;
18
        let (shutdown, _) = broadcast::channel(1);
19

20
        Ok(Server {
21
            listener,
22
            shutdown,
23
            connection_count: Arc::new(AtomicUsize::new(0)),
24
        })
25
    }
26

27
    async fn run(self) -> Result<(), Box<dyn Error>> {
28
        println!("Server listening on {}", self.listener.local_addr()?);
29

30
        loop {
31
            select! {
32
                result = self.listener.accept() => {
33
                    let (socket, addr) = result?;
34
                    self.handle_new_connection(socket, addr);
35
                }
36
                _ = tokio::signal::ctrl_c() => {
37
                    println!("\nShutting down server...");
38
                    self.shutdown.send(()).ok();
39
                    break;
40
                }
41
            }
42
        }
43

44
        // Wait for all connections to close
45
        while self.connection_count.load(Ordering::SeqCst) > 0 {
46
            tokio::time::sleep(tokio::time::Duration::from_millis(100)).await;
47
        }
48

49
        println!("Server shutdown complete");
50
        Ok(())
51
    }
52

53
    fn handle_new_connection(&self, socket: TcpStream, addr: std::net::SocketAddr) {
54
        let mut shutdown_rx = self.shutdown.subscribe();
55
        let count = self.connection_count.clone();
56

57
        count.fetch_add(1, Ordering::SeqCst);
58
        println!("New connection from: {} (total: {})", addr, count.load(Ordering::SeqCst));
59

60
        tokio::spawn(async move {
61
            let result = select! {
62
                res = handle_connection(socket) => res,
63
                _ = shutdown_rx.recv() => {
64
                    println!("Connection {} shutting down", addr);
65
                    Ok(())
66
                }
67
            };
68

69
            if let Err(e) = result {
70
                eprintln!("Error handling connection {}: {}", addr, e);
71
            }
72

73
            count.fetch_sub(1, Ordering::SeqCst);
74
            println!("Connection {} closed (remaining: {})", addr, count.load(Ordering::SeqCst));
75
        });
76
    }
77
}
78

79
async fn handle_connection(mut socket: TcpStream) -> Result<(), Box<dyn Error>> {
80
    let mut buffer = vec![0; 4096];
81

82
    loop {
83
        let n = socket.read(&mut buffer).await?;
84
        if n == 0 {
85
            return Ok(());
86
        }
87

88
        socket.write_all(&buffer[0..n]).await?;
89
    }
90
}
91

92
#[tokio::main]
93
async fn main() -> Result<(), Box<dyn Error>> {
94
    let server = Server::new("127.0.0.1:8080").await?;
95
    server.run().await
96
}

Concurrent Task Management#

Tokio provides several ways to manage concurrent tasks effectively.

Spawning Tasks#

1
use tokio::task;
2
use std::time::Duration;
3

4
#[tokio::main]
5
async fn main() {
6
    // Spawn multiple concurrent tasks
7
    let handles: Vec<_> = (0..5)
8
        .map(|i| {
9
            tokio::spawn(async move {
10
                tokio::time::sleep(Duration::from_secs(1)).await;
11
                println!("Task {} completed", i);
12
                i * 2
13
            })
14
        })
15
        .collect();
16

17
    // Wait for all tasks and collect results
18
    let mut results = Vec::new();
19
    for handle in handles {
20
        let result = handle.await.unwrap();
21
        results.push(result);
22
    }
23

24
    println!("Results: {:?}", results);
25
}

Task Groups with JoinSet#

1
use tokio::task::JoinSet;
2
use std::time::Duration;
3

4
async fn process_item(id: u32) -> Result<String, String> {
5
    tokio::time::sleep(Duration::from_millis(100)).await;
6
    if id % 3 == 0 {
7
        Err(format!("Item {} failed", id))
8
    } else {
9
        Ok(format!("Item {} processed", id))
10
    }
11
}
12

13
#[tokio::main]
14
async fn main() {
15
    let mut set = JoinSet::new();
16

17
    // Spawn multiple tasks
18
    for i in 0..10 {
19
        set.spawn(process_item(i));
20
    }
21

22
    // Process results as they complete
23
    while let Some(result) = set.join_next().await {
24
        match result {
25
            Ok(Ok(msg)) => println!("Success: {}", msg),
26
            Ok(Err(e)) => println!("Task error: {}", e),
27
            Err(e) => println!("Join error: {}", e),
28
        }
29
    }
30
}

Async HTTP Operations#

HTTP Client with Reqwest#

1
// Add to Cargo.toml: reqwest = { version = "0.12", features = ["json"] }
2
use reqwest;
3
use serde::{Deserialize, Serialize};
4
use std::time::Duration;
5

6
#[derive(Debug, Serialize, Deserialize)]
7
struct Post {
8
    id: u32,
9
    title: String,
10
    body: String,
11
    userId: u32,
12
}
13

14
async fn fetch_posts() -> Result<Vec<Post>, reqwest::Error> {
15
    let client = reqwest::Client::builder()
16
        .timeout(Duration::from_secs(10))
17
        .build()?;
18

19
    let posts = client
20
        .get("https://jsonplaceholder.typicode.com/posts")
21
        .send()
22
        .await?
23
        .json::<Vec<Post>>()
24
        .await?;
25

26
    Ok(posts)
27
}
28

29
async fn create_post(post: &Post) -> Result<Post, reqwest::Error> {
30
    let client = reqwest::Client::new();
31

32
    let response = client
33
        .post("https://jsonplaceholder.typicode.com/posts")
34
        .json(post)
35
        .send()
36
        .await?
37
        .json::<Post>()
38
        .await?;
39

40
    Ok(response)
41
}
42

43
#[tokio::main]
44
async fn main() -> Result<(), Box<dyn std::error::Error>> {
45
    // Fetch posts concurrently
46
    let fetch_task = fetch_posts();
47

48
    // Create a new post
49
    let new_post = Post {
50
        id: 0,
51
        title: "My Async Post".to_string(),
52
        body: "Created with Tokio and Reqwest".to_string(),
53
        userId: 1,
54
    };
55
    let create_task = create_post(&new_post);
56

57
    // Wait for both operations
58
    let (posts_result, created_result) = tokio::join!(fetch_task, create_task);
59

60
    match posts_result {
61
        Ok(posts) => println!("Fetched {} posts", posts.len()),
62
        Err(e) => eprintln!("Failed to fetch posts: {}", e),
63
    }
64

65
    match created_result {
66
        Ok(post) => println!("Created post with ID: {}", post.id),
67
        Err(e) => eprintln!("Failed to create post: {}", e),
68
    }
69

70
    Ok(())
71
}

Parallel HTTP Requests with Rate Limiting#

1
use tokio::sync::Semaphore;
2
use std::sync::Arc;
3
use std::time::Instant;
4

5
async fn fetch_url(url: &str) -> Result<String, reqwest::Error> {
6
    let response = reqwest::get(url).await?;
7
    Ok(response.text().await?)
8
}
9

10
async fn fetch_urls_with_limit(urls: Vec<String>, max_concurrent: usize) {
11
    let semaphore = Arc::new(Semaphore::new(max_concurrent));
12
    let start = Instant::now();
13

14
    let tasks: Vec<_> = urls
15
        .into_iter()
16
        .map(|url| {
17
            let permit = semaphore.clone();
18
            tokio::spawn(async move {
19
                let _permit = permit.acquire().await.unwrap();
20
                println!("Fetching: {}", url);
21

22
                match fetch_url(&url).await {
23
                    Ok(content) => {
24
                        println!("Fetched {} bytes from {}", content.len(), url);
25
                        Ok(content.len())
26
                    }
27
                    Err(e) => {
28
                        eprintln!("Error fetching {}: {}", url, e);
29
                        Err(e)
30
                    }
31
                }
32
            })
33
        })
34
        .collect();
35

36
    let mut total_bytes = 0;
37
    let mut errors = 0;
38

39
    for task in tasks {
40
        match task.await.unwrap() {
41
            Ok(bytes) => total_bytes += bytes,
42
            Err(_) => errors += 1,
43
        }
44
    }
45

46
    let elapsed = start.elapsed();
47
    println!(
48
        "\nFetched {} bytes with {} errors in {:?}",
49
        total_bytes, errors, elapsed
50
    );
51
}
52

53
#[tokio::main]
54
async fn main() {
55
    let urls = vec![
56
        "https://www.rust-lang.org".to_string(),
57
        "https://tokio.rs".to_string(),
58
        "https://github.com".to_string(),
59
        "https://docs.rs".to_string(),
60
        "https://crates.io".to_string(),
61
    ];
62

63
    // Limit to 3 concurrent requests
64
    fetch_urls_with_limit(urls, 3).await;
65
}

Working with Channels and Streams#

Multi-Producer Single-Consumer Channel#

1
use tokio::sync::mpsc;
2
use tokio::time::{sleep, Duration};
3

4
async fn producer(id: u32, tx: mpsc::Sender<String>) {
5
    for i in 0..5 {
6
        let msg = format!("Producer {} - Message {}", id, i);
7
        if tx.send(msg.clone()).await.is_err() {
8
            println!("Receiver dropped, stopping producer {}", id);
9
            return;
10
        }
11
        println!("Sent: {}", msg);
12
        sleep(Duration::from_millis(100 * id as u64)).await;
13
    }
14
}
15

16
async fn consumer(mut rx: mpsc::Receiver<String>) {
17
    while let Some(msg) = rx.recv().await {
18
        println!("Received: {}", msg);
19
        sleep(Duration::from_millis(50)).await;
20
    }
21
    println!("All producers done");
22
}
23

24
#[tokio::main]
25
async fn main() {
26
    let (tx, rx) = mpsc::channel(10);
27

28
    // Spawn multiple producers
29
    for i in 1..=3 {
30
        let tx_clone = tx.clone();
31
        tokio::spawn(producer(i, tx_clone));
32
    }
33

34
    // Drop the original sender so the channel closes when all producers are done
35
    drop(tx);
36

37
    // Start the consumer
38
    consumer(rx).await;
39
}

Broadcast Channel for Pub/Sub#

1
use tokio::sync::broadcast;
2
use tokio::time::{sleep, Duration};
3

4
#[derive(Debug, Clone)]
5
enum Event {
6
    UserJoined(String),
7
    MessageSent { user: String, message: String },
8
    UserLeft(String),
9
}
10

11
async fn event_publisher(tx: broadcast::Sender<Event>) {
12
    let events = vec![
13
        Event::UserJoined("Alice".to_string()),
14
        Event::MessageSent {
15
            user: "Alice".to_string(),
16
            message: "Hello everyone!".to_string(),
17
        },
18
        Event::UserJoined("Bob".to_string()),
19
        Event::MessageSent {
20
            user: "Bob".to_string(),
21
            message: "Hi Alice!".to_string(),
22
        },
23
        Event::UserLeft("Alice".to_string()),
24
    ];
25

26
    for event in events {
27
        println!("Publishing: {:?}", event);
28
        if tx.send(event).is_err() {
29
            break;
30
        }
31
        sleep(Duration::from_secs(1)).await;
32
    }
33
}
34

35
async fn event_subscriber(name: &str, mut rx: broadcast::Receiver<Event>) {
36
    while let Ok(event) = rx.recv().await {
37
        println!("{} received: {:?}", name, event);
38
    }
39
    println!("{} finished", name);
40
}
41

42
#[tokio::main]
43
async fn main() {
44
    let (tx, _) = broadcast::channel(16);
45

46
    // Create multiple subscribers
47
    let rx1 = tx.subscribe();
48
    let rx2 = tx.subscribe();
49

50
    // Spawn subscribers
51
    let sub1 = tokio::spawn(event_subscriber("Subscriber 1", rx1));
52
    let sub2 = tokio::spawn(event_subscriber("Subscriber 2", rx2));
53

54
    // Spawn publisher
55
    let pub_task = tokio::spawn(event_publisher(tx));
56

57
    // Wait for all tasks
58
    let _ = tokio::join!(pub_task, sub1, sub2);
59
}

Real-World Examples#

Example 1: Web Scraper with Concurrent Downloads#

1
use reqwest;
2
use tokio::fs::File;
3
use tokio::io::AsyncWriteExt;
4
use tokio::sync::Semaphore;
5
use std::sync::Arc;
6
use std::path::Path;
7

8
struct Downloader {
9
    client: reqwest::Client,
10
    semaphore: Arc<Semaphore>,
11
}
12

13
impl Downloader {
14
    fn new(max_concurrent: usize) -> Self {
15
        Self {
16
            client: reqwest::Client::new(),
17
            semaphore: Arc::new(Semaphore::new(max_concurrent)),
18
        }
19
    }
20

21
    async fn download_file(&self, url: &str, path: &str) -> Result<(), Box<dyn std::error::Error>> {
22
        let _permit = self.semaphore.acquire().await?;
23

24
        println!("Downloading: {}", url);
25
        let response = self.client.get(url).send().await?;
26
        let bytes = response.bytes().await?;
27

28
        let mut file = File::create(path).await?;
29
        file.write_all(&bytes).await?;
30

31
        println!("Saved: {} ({} bytes)", path, bytes.len());
32
        Ok(())
33
    }
34

35
    async fn download_batch(&self, downloads: Vec<(&str, &str)>) {
36
        let tasks: Vec<_> = downloads
37
            .into_iter()
38
            .map(|(url, path)| {
39
                let url = url.to_string();
40
                let path = path.to_string();
41
                let downloader = self.clone();
42

43
                tokio::spawn(async move {
44
                    if let Err(e) = downloader.download_file(&url, &path).await {
45
                        eprintln!("Failed to download {}: {}", url, e);
46
                    }
47
                })
48
            })
49
            .collect();
50

51
        for task in tasks {
52
            let _ = task.await;
53
        }
54
    }
55
}
56

57
impl Clone for Downloader {
58
    fn clone(&self) -> Self {
59
        Self {
60
            client: self.client.clone(),
61
            semaphore: self.semaphore.clone(),
62
        }
63
    }
64
}
65

66
#[tokio::main]
67
async fn main() -> Result<(), Box<dyn std::error::Error>> {
68
    let downloader = Downloader::new(3); // Max 3 concurrent downloads
69

70
    let downloads = vec![
71
        ("https://www.rust-lang.org/logos/rust-logo-512x512.png", "rust-logo.png"),
72
        ("https://tokio.rs/img/tokio-horizontal.svg", "tokio-logo.svg"),
73
        // Add more URLs as needed
74
    ];
75

76
    downloader.download_batch(downloads).await;
77
    Ok(())
78
}

Example 2: Chat Server with WebSockets#

1
use tokio::net::{TcpListener, TcpStream};
2
use tokio::sync::{broadcast, RwLock};
3
use std::collections::HashMap;
4
use std::sync::Arc;
5
use std::net::SocketAddr;
6

7
#[derive(Debug, Clone)]
8
struct Message {
9
    user: String,
10
    content: String,
11
}
12

13
struct ChatServer {
14
    users: Arc<RwLock<HashMap<SocketAddr, String>>>,
15
    broadcast: broadcast::Sender<Message>,
16
}
17

18
impl ChatServer {
19
    fn new() -> Self {
20
        let (tx, _) = broadcast::channel(100);
21
        Self {
22
            users: Arc::new(RwLock::new(HashMap::new())),
23
            broadcast: tx,
24
        }
25
    }
26

27
    async fn handle_client(&self, socket: TcpStream, addr: SocketAddr) {
28
        let mut rx = self.broadcast.subscribe();
29
        let users = self.users.clone();
30
        let tx = self.broadcast.clone();
31

32
        // Register user
33
        {
34
            let mut users_lock = users.write().await;
35
            users_lock.insert(addr, format!("User_{}", addr.port()));
36
        }
37

38
        // Announce user joined
39
        let join_msg = Message {
40
            user: "System".to_string(),
41
            content: format!("User {} joined", addr),
42
        };
43
        let _ = tx.send(join_msg);
44

45
        // Handle messages (simplified - in real app, use WebSocket protocol)
46
        tokio::spawn(async move {
47
            loop {
48
                tokio::select! {
49
                    msg = rx.recv() => {
50
                        match msg {
51
                            Ok(msg) => {
52
                                // Send message to client
53
                                println!("Broadcasting to {}: {:?}", addr, msg);
54
                            }
55
                            Err(_) => break,
56
                        }
57
                    }
58
                }
59
            }
60

61
            // User disconnected
62
            let mut users_lock = users.write().await;
63
            users_lock.remove(&addr);
64

65
            let leave_msg = Message {
66
                user: "System".to_string(),
67
                content: format!("User {} left", addr),
68
            };
69
            let _ = tx.send(leave_msg);
70
        });
71
    }
72

73
    async fn run(&self, addr: &str) -> Result<(), Box<dyn std::error::Error>> {
74
        let listener = TcpListener::bind(addr).await?;
75
        println!("Chat server listening on {}", addr);
76

77
        loop {
78
            let (socket, addr) = listener.accept().await?;
79
            self.handle_client(socket, addr).await;
80
        }
81
    }
82
}

Performance Tips and Best Practices#

1. Choose the Right Runtime Features#

1
# Minimal features for specific use cases
2
[dependencies]
3
tokio = { version = "1.43", features = ["rt-multi-thread", "net", "time"] }
4

5
# Full features for development
6
[dependencies]
7
tokio = { version = "1.43", features = ["full"] }

2. Avoid Blocking Operations#

1
// Bad - blocks the async runtime
2
async fn bad_example() {
3
    std::thread::sleep(std::time::Duration::from_secs(1)); // BLOCKING!
4
    std::fs::read_to_string("file.txt").unwrap(); // BLOCKING!
5
}
6

7
// Good - use async alternatives
8
async fn good_example() {
9
    tokio::time::sleep(tokio::time::Duration::from_secs(1)).await;
10
    tokio::fs::read_to_string("file.txt").await.unwrap();
11
}
12

13
// For CPU-intensive work, use spawn_blocking
14
async fn cpu_intensive_example() {
15
    let result = tokio::task::spawn_blocking(|| {
16
        // CPU-intensive computation
17
        expensive_computation()
18
    }).await.unwrap();
19
}

3. Buffer Sizes Matter#

1
// Configure channel buffer sizes based on workload
2
let (tx, rx) = mpsc::channel(100); // Buffered channel
3

4
// For unbounded channels (use with caution)
5
let (tx, rx) = mpsc::unbounded_channel();

4. Use Select for Complex Control Flow#

1
use tokio::select;
2

3
async fn complex_flow() {
4
    let mut interval = tokio::time::interval(Duration::from_secs(1));
5
    let mut shutdown = tokio::signal::ctrl_c();
6

7
    loop {
8
        select! {
9
            _ = interval.tick() => {
10
                println!("Tick");
11
            }
12
            _ = &mut shutdown => {
13
                println!("Shutting down");
14
                break;
15
            }
16
        }
17
    }
18
}

5. Handle Backpressure#

1
async fn handle_backpressure(tx: mpsc::Sender<String>) {
2
    for i in 0..1000 {
3
        // Check if receiver is keeping up
4
        if tx.capacity() == 0 {
5
            println!("Channel full, applying backpressure");
6
            tokio::time::sleep(Duration::from_millis(100)).await;
7
        }
8

9
        let _ = tx.send(format!("Message {}", i)).await;
10
    }
11
}

6. Monitor Task Health#

1
use std::time::Instant;
2

3
async fn monitored_task(id: u32) {
4
    let start = Instant::now();
5

6
    // Task work here
7
    tokio::time::sleep(Duration::from_secs(2)).await;
8

9
    let duration = start.elapsed();
10
    if duration > Duration::from_secs(1) {
11
        eprintln!("Task {} took too long: {:?}", id, duration);
12
    }
13
}

Common Pitfalls and Solutions#

Pitfall 1: Forgetting to Await#

1
// Wrong - Future is created but not executed
2
async fn wrong() {
3
    fetch_data(); // Missing .await
4
}
5

6
// Correct
7
async fn correct() {
8
    fetch_data().await;
9
}

Pitfall 2: Holding Locks Across Await Points#

1
use tokio::sync::Mutex;
2

3
// Bad - holds lock across await
4
async fn bad_lock_usage(data: Arc<Mutex<Vec<String>>>) {
5
    let mut guard = data.lock().await;
6
    tokio::time::sleep(Duration::from_secs(1)).await; // Lock held for 1 second!
7
    guard.push("data".to_string());
8
}
9

10
// Good - minimize lock scope
11
async fn good_lock_usage(data: Arc<Mutex<Vec<String>>>) {
12
    tokio::time::sleep(Duration::from_secs(1)).await;
13

14
    let mut guard = data.lock().await;
15
    guard.push("data".to_string());
16
    // Lock automatically released here
17
}

Pitfall 3: Not Handling Task Panics#

1
// Handle panics gracefully
2
async fn safe_task_spawn() {
3
    let handle = tokio::spawn(async {
4
        // Task that might panic
5
        panic!("Oh no!");
6
    });
7

8
    match handle.await {
9
        Ok(_) => println!("Task completed"),
10
        Err(e) if e.is_panic() => {
11
            println!("Task panicked: {:?}", e);
12
        }
13
        Err(e) => println!("Task error: {:?}", e),
14
    }
15
}

Conclusion#

Tokio provides a powerful foundation for building high-performance async applications in Rust. By understanding its core concepts and following best practices, you can build servers that handle thousands of concurrent connections efficiently.

Key takeaways:

Use tokio::spawn for concurrent task execution
Leverage channels for inter-task communication
Avoid blocking operations in async contexts
Use select! for complex control flow
Handle errors and panics gracefully
Monitor and profile your async applications

Next Steps#

Ready to dive deeper into async Rust? Check out:

Happy async coding!