Apache Module mod_reqtimeout
| Description: | Set timeout and minimum data rate for receiving requests |
|---|---|
| Status: | Extension |
| Module Identifier: | reqtimeout_module |
| Source File: | mod_reqtimeout.c |
| Compatibility: | Available in Apache HTTPD 2.2.15 and later |
Summary
This module provides a convenient way to set timeouts and minimum data rates for receiving requests. Should a timeout occur or a data rate be to low, the corresponding connection will be closed by the server.
This is logged at LogLevel info.
If needed, the LogLevel directive can be tweaked to explicitly log it:
LogLevel reqtimeout:info
Examples
- Allow for 5 seconds to complete the TLS handshake, 10 seconds to receive the request headers and 30 seconds for receiving the request body:
RequestReadTimeout handshake=5 header=10 body=30
- Allow at least 10 seconds to receive the request body. If the client sends data, increase the timeout by 1 second for every 1000 bytes received, with no upper limit for the timeout (except for the limit given indirectly by
LimitRequestBody):RequestReadTimeout body=10,MinRate=1000
- Allow at least 10 seconds to receive the request headers. If the client sends data, increase the timeout by 1 second for every 500 bytes received. But do not allow more than 30 seconds for the request headers:
RequestReadTimeout header=10-30,MinRate=500
- Usually, a server should have both header and body timeouts configured. If a common configuration is used for http and https virtual hosts, the timeouts should not be set too low:
RequestReadTimeout header=20-40,MinRate=500 body=20,MinRate=500
RequestReadTimeout Directive
| Description: | Set timeout values for completing the TLS handshake, receiving the request headers and/or body from client. |
|---|---|
| Syntax: | RequestReadTimeout [handshake=timeout[-maxtimeout][,MinRate=rate] [header=timeout[-maxtimeout][,MinRate=rate] [body=timeout[-maxtimeout][,MinRate=rate] |
| Default: | RequestReadTimeout handshake=0 header=20-40,MinRate=500 body=20,MinRate=500 |
| Context: | server config, virtual host |
| Status: | Extension |
| Module: | mod_reqtimeout |
| Compatibility: | Available in version 2.2.15 and later; defaulted to disabled in version 2.3.14 and earlier. The handshake stage is available since version 2.4.39. |
This directive can set various timeouts for completing the TLS handshake, receiving the request headers and/or the request body from the client. If the client fails to complete each of these stages within the configured time, a 408 REQUEST TIME OUT error is sent.
For SSL virtual hosts, the handshake timeout values is the time needed to do the initial SSL handshake. If the user's browser is configured to query certificate revocation lists and the CRL server is not reachable, the initial SSL handshake may take a significant time until the browser gives up waiting for the CRL. Therefore the handshake timeout should take this possible overhead into consideration for SSL virtual hosts (if necessary). The body timeout values include the time needed for SSL renegotiation (if necessary).
When an AcceptFilter is in use (usually the case on Linux and FreeBSD), the socket is not sent to the server process before at least one byte (or the whole request for httpready) is received. The handshake and header timeouts configured with RequestReadTimeout are only effective after the server process has received the socket.
For each of the three timeout stages (handshake, header or body), there are three ways to specify the timeout:
- Fixed timeout value:
stage=timeoutThe time in seconds allowed for completing the whole stage (handshaking, reading all of the request headers or body). A value of 0 means no limit.
- Disable module for a vhost:
handshake=0 header=0 body=0This disables
mod_reqtimeoutcompletely (note thathandshake=0is the default already and could be omitted). - Timeout value that is increased when data is received:
stage=timeout,MinRate=data_rateSame as above, but whenever data is received, the timeout value is increased according to the specified minimum data rate (in bytes per second).
- Timeout value that is increased when data is received, with an upper bound:
stage=timeout-maxtimeout,MinRate=data_rateSame as above, but the timeout will not be increased above the second value of the specified timeout range.
