ETag: "60874b-709d-45c8df58"
[...snip...]
ETag: "15c02de-709d-45c8df58"
[...snip...]
- Does it matter that the ETag varies between successive requests? Reason I ask is that
the http://www.web-caching.com/mnot_tutorial/how.html page says: "HTTP 1.1 introduced a new kind of validator called the ETag. ETags are unique identifiers that are generated by the server and changed every time the object does. Because the server controls how the ETag is generated, caches can be surer that if the ETag matches when they make a If-None-Match request, the object really is the same."
I.e. if the ETag changes between requests, as it did in the above example, could that make requesters think that the object has changed too, thus reducing caching?
Just found how to stop this - The ETag comes from 3 sources of information - the inode, the file size, and the file modified time.
That's why these two are different yet similar:
ETag: "60874b-709d-45c8df58" ETag: "15c02de-709d-45c8df58"
I.e. the format currently is ETag: "<inode value>-<date value>-<file size value>". [which is the apache2 default, I think].
The inodes differ for the different systems, but the date and the file values are the same, as you can see.
The solution therefore is to add this line to the cluster's apache2.conf: ------------------------- FileETag MTime Size -------------------------
Then the result will be: ETag: "709d-45c8df58" for all boxes serving this example file.
All the best, Nick.