A timeout ends or fails an operation after it waits beyond an allowed duration. A common mistake is using http.Get or an empty http.Client in production: the default client has no timeout, so a request can wait indefinitely and exhaust resources. section 10.7.1
Match the timeout to the HTTP operation being bounded:
- net.Dialer.Timeout limits establishing the TCP connection. section 10.7.1
- http.Transport.TLSHandshakeTimeout limits the TLS handshake. section 10.7.1
- http.Transport.ResponseHeaderTimeout limits waiting for response headers. section 10.7.1
- http.Client.Timeout bounds the complete request, from dialing through reading the response body. section 10.7.1
Bound both stages and the whole request
client := &http.Client{ Timeout: 5 * time.Second, Transport: &http.Transport{ DialContext: (&net.Dialer{ Timeout: time.Second, }).DialContext, TLSHandshakeTimeout: time.Second, ResponseHeaderTimeout: time.Second, }, } section 10.7.1
Timeouts also arrive through context cancellation. A context-aware function should use select around channel sends and receives, returning ctx.Err() when cancellation or a deadline occurs instead of remaining blocked. section 8.6.4
client := &http.Client{
Timeout: 5 * time.Second, #1
Transport: &http.Transport{
DialContext: (&net.Dialer{
Timeout: time.Second, #2
}).DialContext,
TLSHandshakeTimeout: time.Second, #3
ResponseHeaderTimeout: time.Second, #4
},
}
Inspect a complete client configuration that combines a global request timeout with dial, TLS, and response-header limits. section 10.7.1
