Better analysis of HTTP caching headers

[netgrind.git] / README

diff --git a/README b/README
index 97f48e1d8efb6645beb3651eaac129ef42fea014..71a02ddc471b172dfde3fcda69fad85e6def8221 100644 (file)
--- a/README
+++ b/README
@@ -58,7 +58,7 @@ global
 transaction ID                                                                    cache status --+    |      |   duration [sec]    |   request URI
   |                     source address:port   destination addr:port                              |    |      |         |           |    |
   |                               |                     |                                        |    |      |         |           |    |
-000001 2003-06-06 22:53:38.642 81.27.194.19:1175     205.217.153.53:80     123.123.123.123 200 ...   0    14030      0.957      0.444 GET http://...
+000001 2003-06-06 22:53:38.642 81.27.194.19:1175     205.217.153.53:80     123.123.123.123 200 ....   0    14030      0.957      0.444 GET http://...
          |                                                                         |         |
        date and time of request start                                    X-Forwarded-For    HTTP response code or
        (if it's the first request on a connection,                                          ERR = HTTP violation
@@ -71,12 +71,24 @@ Cache status codes:
        1st char: request cacheing control      . = none
                                                N = don't cache
                                                R = revalidate
+
        2nd char: response cacheability         . = not restricted
        (first matching letter used)            N = don't cache
                                                P = private
                                                S = don't store to non-volatile storage
+                                               X = already expired
+                                               V = "Vary:" header present
                                                R = must be revalidated
-       3rd char: cache response                . = X-Cache not found
+                                               E = short expiration time (less than 5min)
+                                               L = long expiration time (5min or more)
+                                               lowercase version = but cached by a HTTP/1.0 cache
+
+       3rd char: response validator            . = none
+                                               E = ETag
+                                               W = weak ETag
+                                               L = Last-Modified
+
+       4th char: cache response                . = X-Cache not found
        (X-Cache header, optional)              - = MISS
                                                + = HIT
                                                ? = other