Hello, For at least one site that I am using Varnish Cache for, the allocated cache size is fully utilised and objects are now being nuked/evicted from the cache. Before I blindly supply more resources to provide a larger cache, I'd like to understand if the cache space is being used optimally.
For example, of the objects that are expiring naturally, were they ever used to serve a cache hit? If not, it was probably wasteful to store them in the cache in the first place. Of the objects that are being nuked/evicted, were they close to their natural expiration time anyway? Were they ever used to serve a cache hit? Of the objects that have been nuked, are they requested shortly after, suggesting it may have been worth having a larger cache in order to retain them a bit longer? I did not see an easy way to answer these questions with the standard Varnish toolset - am I missing something? I looked through the code paths in Varnish 5.1 responsible for expiration and nuking and it seems the object hit count and ttl is available in that context - would it be worth writing a patch to log these fields to the VSL? How do others ensure their allocated cache size is well utilised before growing the cache? Regards, Jason _______________________________________________ varnish-misc mailing list [email protected] https://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc
