Browser & Web Performance · Senior · Question 35 of 75

Why might `ETag`s generated from inode or modification time cause poor cache revalidation behind a load balancer?

1ETags are stripped by load balancers
✓Correct answer: Different servers produce different ETags for the same file, so If-None-Match often misses and full responses are sent
3Load balancers don't support 304

Explanation

Content-hash ETags are consistent across servers. Weak ETags (W/) may also be required when compression changes the bytes.

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