Modules | Directives | FAQ | Glossary | Sitemap
Apache HTTP Server Version 2.4
Apache > HTTP Server > Documentation > Version 2.4 > Modules
Apache Module mod_logio
| Description: | Logging of input and output bytes per request |
|---|---|
| Status: | Extension |
| Module Identifier: | logio_module |
| Source File: | mod_logio.c |
Summary
This module provides the logging of input and output number of bytes received/sent per request. The numbers reflect the actual bytes as received on the network, which then takes into account the headers and bodies of requests and responses. The counting is done before SSL/TLS on input and after SSL/TLS on output, so the numbers will correctly reflect any changes made by encryption.
This module requires mod_log_config.
When KeepAlive connections are used with SSL, the overhead of the SSL handshake is reflected in the byte count of the first request on the connection. When per-directory SSL renegotiation occurs, the bytes are associated with the request that triggered the renegotiation.
Topics
Directives
Bugfix checklist
See also
Custom Log Formats
This module adds three new logging directives. The characteristics of the request itself are logged by placing "%" directives in the format string, which are replaced in the log file by the values as follows:
| Format String | Description |
|---|---|
| %I | Bytes received, including request and headers, cannot be zero. |
| %O | Bytes sent, including headers, cannot be zero. |
| %S | Bytes transferred (received and sent), including request and headers,
cannot be zero. This is the combination of %I and %O. Available in Apache 2.4.7 and later |
| %^FB | Delay in microseconds between when the request arrived and the
first byte of the response headers are written. Only available if
LogIOTrackTTFB is set to ON. Available in Apache 2.4.13 and later |
Usually, the functionality is used like this:
- Combined I/O log format:
- "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-agent}i\" %I %O"
LogIOTrackTTFB Directive
| Description: | Enable tracking of time to first byte (TTFB) |
|---|---|
| Syntax: | LogIOTrackTTFB ON|OFF |
| Default: | LogIOTrackTTFB OFF |
| Context: | server config, virtual host, directory, .htaccess |
| Override: | none |
| Status: | Extension |
| Module: | mod_logio |
| Compatibility: | Apache HTTP Server 2.4.13 and later |
This directive configures whether this module tracks the delay between the request being read and the first byte of the response headers being written. The resulting value may be logged with the %^FB format.