Request Limits & DoS Hardening ​
Prevent denial-of-service (DoS) attacks by enforcing strict limits on request sizes and connection counts.
Configurable Limits ​
var server = try httpx.Server.init(allocator, io, .{
.maxBody = 10 * 1024 * 1024, // 10 MB body payload limit
.maxRequestsPerConn = 1000, // cap requests per keep-alive connection
});
defer server.deinit();| Limit | Default | Purpose |
|---|---|---|
maxBody | 8 MB | Rejects oversized payloads |
maxRequestsPerConn | 1000 | Bounds keep-alive reuse per connection |
maxConcurrentConnections | 128 | Caps active and queued connection tasks |
maxQueuedConnectionTasks | 128 | Bounds pending work; new connections are closed when full |
initialRequestTimeoutMs | 5000 | Bounds the wait for initial request bytes |
headerReadTimeoutMs | 10000 | Absolute deadline to finish request headers |
requestBodyTimeoutMs | 30000 | Absolute deadline to receive the complete body |
writeTimeoutMs | 30000 | Absolute response write deadline |
keepAliveIdleTimeoutMs | 30000 | Bounds idle keep-alive reads |
Pair with httpx.RateLimiter middleware for per-IP request-rate enforcement.
Slowloris Attack Mitigation ​
The server processes connections through a bounded worker pool, so a client waiting before sending data does not block the accept loop or unrelated workers. maxConcurrentConnections bounds active plus queued connections, and a full limit closes newly accepted sockets. The initial-byte, header, body, write, and keep-alive settings in the inline options passed to httpx.Server.init use absolute phase deadlines; sending occasional bytes does not extend the header or body deadline. Set these deadlines to finite values for exposed services. Setting one to zero disables that deadline and can let a stalled peer occupy a worker until another limit or shutdown intervenes. A handler that blocks in application code is not forcibly cancelled. A reverse proxy or load balancer can add another independent resource boundary, but does not replace server-side limits.