Challenge 1: Defining the product_cache Zone — Solution Walkthrough

The configuration:

  proxy_cache_path /var/cache/nginx/product_cache levels=1:2 keys_zone=product_cache:5m max_size=500m inactive=30m;

Why this works:

keys_zone=product_cache:5m names the zone product_cache and reserves
5MB of shared memory for cache keys/metadata, per this chapter's own
explanation that this memory allocation is separate from the actual
cached content. max_size=500m caps the total disk space the cached
response bodies themselves can use at 500MB. inactive=30m removes any
entry that hasn't been accessed in 30 minutes, regardless of how long
ago it was first cached — exactly the three requirements specified.

WHY THIS WORKS AS AN ANSWER
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This exercise is a direct, hands-on application of this chapter's own
proxy_cache_path example to new specific values, correctly keeping the
keys_zone size (5MB, for metadata) and max_size (500MB, for actual
content) as two clearly distinct numbers rather than conflating them.