svn commit: r1465881 - /trafficserver/site/trunk/content/docs/trunk/sdk/troubleshooting-tips/unable-to-debug-tags.en.mdtext

[am...@apache.org]

Author: amc
Date: Tue Apr  9 04:42:22 2013
New Revision: 1465881

URL: http://svn.apache.org/r1465881
Log:
More detail for using debug tags

Modified:
    trafficserver/site/trunk/content/docs/trunk/sdk/troubleshooting-tips/unable-to-debug-tags.en.mdtext

Modified: trafficserver/site/trunk/content/docs/trunk/sdk/troubleshooting-tips/unable-to-debug-tags.en.mdtext
URL: http://svn.apache.org/viewvc/trafficserver/site/trunk/content/docs/trunk/sdk/troubleshooting-tips/unable-to-debug-tags.en.mdtext?rev=1465881&r1=1465880&r2=1465881&view=diff
==============================================================================
--- trafficserver/site/trunk/content/docs/trunk/sdk/troubleshooting-tips/unable-to-debug-tags.en.mdtext (original)
+++ trafficserver/site/trunk/content/docs/trunk/sdk/troubleshooting-tips/unable-to-debug-tags.en.mdtext Tue Apr  9 04:42:22 2013
@@ -24,7 +24,7 @@ to add traces in your plugin. In this AP
 * `tag` is the Traffic Server parameter that enables Traffic Server to print 
 out _`format_str`_
 
-* `...` is a variable for _`format_str`_
+* `...` are variables for _`format_str`_ in the standard `printf` style.
 
 Run Traffic Server with the `-Ttag` option. For example, if the tag is
 `my-plugin`, then the debug output goes to `traffic.out.`See below:
@@ -55,12 +55,38 @@ Server with the `my-plugin` tag:
 
 ### Other Useful Internal Debug Tags ### {#OtherUsefulInternalDebugTags}
 
-Traffic Server provides many debug tags for internal debugging purposes. Some 
+Embedded in the base Traffic Server code are many debug tags for internal debugging purposes. These can also be used to follow Traffic Server behavior for testing and analysis.
+
+The debug tag setting (`-T` and `proxy.config.diag.debug.tags`) is a anchored regular expression against which the tag for a specific debug message is matched. This means the value "http" matches debug emssages with the tag "http" but also "http_seq" and "http_trans". If you want multiple tags then use a pipe symbol to separate the tags. For example "http_tproxy|dns|hostdb" will match any of the message tags "http_tproxy", "dns", "hostdb", or "dns_srv" (but not "http_trans" nor "splitdns").
+
+Some 
 of the useful HTTP debug tags are:
 
 * `http_hdrs` - traces all incoming and outgoing HTTP headers.
 
-* `http.*` - traces all the STTP SM debug statements.
+* `http_trans` - traces actions in an HTTP transaction.
+
+* `http_seq` - traces the sequence of the HTTP state machine.
+
+* `http_tproxy` - transparency related HTTP events
+
+* `dns` - DNS operations
+
+* `hostdb` - Host name lookup
+
+* `iocore_net` - Socket and low level IO (very voluminous)
+
+* `socket` - socket operations
+
+* `ssl` - SSL related events
+
+* `cache` - Cache operations (many subtags, examine the output to narrow the tag set)
+
+* `cache_update` - Cache updates including writes
+
+* `cache_read` - Cache read events.
+
+* `dir_probe` - Cache searches.
 
 * `sdk` - gives some warning concerning API usage.