Cache

Caching Behavior and Test Cases

Arxignis honors your origin server’s caching directives.

How to purge cache?

---

1. Cache Decision Flow

flowchart TD
  A[Client Request] --> B{Method is GET?}
  B -->|No| Z[Do Not Cache]
  B -->|Yes| C{Has Set-Cookie header?}
  C -->|Yes| Z
  C -->|No| D{Cache-Control header}

  D -->|private, no-store, no-cache, max-age=0| Z
  D -->|public with max-age > 0| E[Cache - TTL from max-age]
  D -->|missing or unrecognized| F{Expires header present?}

  F -->|Future date| G[Cache - TTL from Expires header]
  F -->|No header or expired| H[Cache based on status code]

  E --> I[Store and Serve]
  G --> I
  H --> I

---

2. No-Cache Conditions

Arxignis does not cache the resource when any of the following are true:

• HTTP method ≠ GET.
• Set-Cookie header is present.
• Cache-Control header includes any of:
• private
• no-store
• no-cache
• max-age=0

---

3. Cache-Allowed Conditions

Arxignis does cache the resource when any of the following are true and no earlier “no-cache” rule applies:

1. Cache-Control: public; max-age=N → Cache with TTL = N seconds.

2. Expires: <future-date> → Cache with TTL = (Expires − now).

3. No Cache-Control header → Cache based on the HTTP status code (e.g. 200 OK).

Note If both max-age and Expires are present, max-age takes precedence.

---

4. Default Cached File Extensions

Arxignis caches by file extension (not by MIME type). By default, Arxignis does not cache .html or .json but does cache robots.txt.

A–F	G–L	M–R	S–Z
.7Z	.GZ	.MIDI	.SVG
.AVI	.ICO	.MKV	.SVGZ
.APK	.JAR	.MP3	.SWF
.BIN	.JPEG	.MP4	.TAR
.BMP	.JPG	.OGG	.TF   (TTF)
.BZ2	.JS	.PDF	.WEBM
.CLASS	.MID	.PLS	.WEBP
.CSV	.MP3	.PPT	.WOFF
.CSS	.MPEG	.PPTX	.WOFF2
.DOC	.OGG	.RAR	.XLS
.DOCX	.OTF	.SVG	.XLSX
.DMG	.PDF	.SWF	.ZIP

---

7. Test Matrix

Below are example test cases to validate Arxignis caching logic.

#	Method	URL	Cache-Control	Expires	Set-Cookie	Ext.	Expected
1	GET	/image.png	private, max-age=3600	—	—	.png	No cache (private)
2	GET	/style.css	public, max-age=600	—	—	.css	Cached (TTL=600s)
3	GET	/index.html	—	Fri, 30 Dec 2099	—	.html	No cache (HTML not cached by default)
4	GET	/robots.txt	—	—	—	.txt	Cached (status-based)
5	GET	/data.json	public, max-age=0	—	—	.json	No cache (max-age=0)
6	GET	/download.zip	—	—	—	.zip	Cached (status-based)
7	GET	/post/submit	—	—	—	—	No cache (no extension & default)
8	POST	/api/submit	public, max-age=3600	—	—	—	No cache (method ≠ GET)
9	GET	/preview.jpg	no-store	—	—	.jpg	No cache (no-store)
10	GET	/video.mp4	—	Thu, 01 Jan 1970	—	.mp4	No cache (expired Expires)
11	GET	/icon.svg	public, max-age=120, Expires: future	—	—	.svg	Cached (use max-age=120 over Expires)
12	GET	/secret.bin	—	—	ID=1234	.bin	No cache (Set-Cookie present)

1. Status-based caching (200 OK, .png/.zip)
2. Edge Cache TTL can be tested by asserting TTL ≠ origin header TTL.
3. Origin Cache-Control Off (Enterprise) should allow you to bypass origin directives.

---

How to Run These Tests

1. Send HTTP requests as defined in the test matrix.
2. Inspect the Age header or your /cache-status log to verify hits vs. misses and TTLs.
3. Repeat with an overriding Edge TTL rule to confirm override behavior.

---