Let’s put the speculation that we have now seen above into follow. I’ll arrange a two-tiered HTTP cache:
- The primary tier caches assets regionally for 10 seconds utilizing
Cache-Management - The second tier makes use of
ETagto keep away from optimizing the info load over the community
I’ll use Apache APISIX. APISIX sits on the shoulder of giants, specifically NGINX. NGINX provides ETag response headers by default.
We solely want so as to add the Cache-Management response header. We obtain it with the response-rewrite plugin:
upstreams:
- id: 1
sort: roundrobin
nodes:
"content material:8080": 1
routes:
- uri: /*
upstream_id: 1
plugins:
response-rewrite:
headers:
set:
Cache-Management: "max-age=10"Let’s do it and not using a browser first.
HTTP/1.1 200 OK Content material-Kind: textual content/html; charset=utf-8 Content material-Size: 147 Connection: keep-alive Date: Thu, 24 Nov 2022 08:21:36 GMT Settle for-Ranges: bytes Final-Modified: Wed, 23 Nov 2022 13:58:55 GMT ETag: "637e271f-93" Server: APISIX/3.0.0 Cache-Management: max-age=10
To forestall the server from sending the identical useful resource, we are able to use the ETag worth in an If-None-Match request header:
curl -H 'If-None-Match: "637e271f-93"' -v localhost:9080The result’s a 304 Not Modified as anticipated:
HTTP/1.1 304 Not Modified Content material-Kind: textual content/html; charset=utf-8 Content material-Size: 147 Connection: keep-alive Date: Thu, 24 Nov 2022 08:26:17 GMT Settle for-Ranges: bytes Final-Modified: Wed, 23 Nov 2022 13:58:55 GMT ETag: "637e271f-93" Server: APISIX/3.0.0 Cache-Management: max-age=10
Now, we are able to do the identical inside a browser. If we use the resend function a second time earlier than 10 seconds have handed, the browser returns the useful resource from the cache with out sending the request to the server.
