Debug Variables

The debug output will be written to the error.log. Please keep in mind that you can have only one global error.log.

If you don't know which debug option to go for, start with

debug.log-request-handling = "enable" 

To enable these settings, set them to "enable".

Core

debug.log-request-header
log all request headers.

default: disabled

debug.log-request-header-on-error
log request header, but only when there is an error.

default: disabled

debug.log-response-header
log the header we send out to the client.

default: disabled

debug.log-file-not-found
log if a file wasn't found.

default: disabled

debug.log-request-handling
log request handling inside lighttpd.

default: disabled

debug.log-condition-handling
log conditionals handling for debugging

default: disabled
See http://blog.lighttpd.net/articles/2006/04/02/log-condition-handling-the-hidden-feature-for-debuging

debug.log-condition-cache-handling
for developers only

default: disabled

debug.log-ssl-noise
log some ssl warnings we hide by default (ssl handshake, unknown/bad certificate).

default: disabled

debug.log-timeouts
NOTE: a request for /xxx.. timed out after writing xxx bytes. We waited xxx seconds. If this a problem increase server.max-write-idle

default: disabled

mod_fcgi - Fastcgi Module

fastcgi.debug
a value between 0 and 65535 to set the debug-level in the FastCGI module. Currently only 0 and 1 are used. Use 1 to enable some debug output, 0 to disable it.

see also fastcgi troubleshooting (bottom of page)

mod_auth - Authentication Module

auth.debug
0 for off, 1 for 'auth-ok' messages, 2 for verbose debugging

mod_proxy - Proxy Module

proxy.debug
a value between 0 and 65535 to set the debug-level in the Proxy module. Currently only 0 and 1 are used. Use 1 to enable some debug output, 0 to disable it.

mod_proxy_core - Proxy Core Module (Version 1.5)

proxy-core.debug
a value between 0 and 65535 to set the debug-level in the Proxy module. Currently only 0 and 1 are used. Use 1 to enable some debug output, 0 to disable it.

mod_simple_vhost - Simple Vhost Module

simple-vhost.debug = 1

mod_trigger_b4_dl - Trigger Before Download Module

trigger-before-download.debug = "disable"

mod_status - Status Module

mod_status is also a great tool to troubleshoot lighttpd.
The server status module generates the status overview of the webserver. The information covers:

  • uptime
  • average throughput
  • current throughput
  • active connections and their state

Documentation for mod_status

mod_webdav - !WebDav module

webdav.log-xml = "enable"

log the XML Request bodies for debugging

See Also