AEM 6.5 / AMS Guardrails (Core-7)

Use this checklist before proposing or applying Dispatcher/HTTPD changes in AMS deployments.

1) Tier Topology And Farm Ordering

Treat AMS as a multi-tier topology when applicable:

• author tier (000_ams_author_farm.any)
• optional LiveCycle/forms tier (001_ams_lc_farm.any)
• publish tier (999_ams_publish_farm.any)

Farm matching is order-sensitive; keep numeric-prefix ordering explicit and deterministic.

2) Variable-Driven Renders And Docroots

Prefer AMS variables over hardcoded endpoints and paths:

• publish: ${PUBLISH_IP}, ${PUBLISH_PORT}, ${PUBLISH_DOCROOT}
• author: ${AUTHOR_IP}, ${AUTHOR_PORT}, ${AUTHOR_DOCROOT}
• optional forms tier: ${LIVECYCLE_IP}, ${LIVECYCLE_PORT}, ${LIVECYCLE_DOCROOT}

For 6.5/AMS guidance, flag hardcoded render hosts/docroots as drift risk unless intentionally required.

When advising where to manage defaults, point to conf.d/variables/ams_default.vars.

3) Author vs Publish Behavior Boundaries

Keep tier-specific directives in the correct farm:

• author-only patterns: /sessionmanagement, /homepage
• publish-only vanity polling: /vanity_urls with /delay
• cache policy defaults should explain why statfileslevel, /enableTTL, /serveStaleOnError, and /gracePeriod are chosen

Do not copy author session behavior into publish farms.

4) Flush/Invalidation Safety

Treat flush access as a security control:

• /allowedClients must be deny-first, then explicit publish IP allows
• avoid wildcard allow patterns for flush endpoints
• keep replication-based flush setup aligned across publish instances
• keep invalidate allow-list updates scoped to mutable AMS files (for example ams_*_invalidate_allowed.any)
• when recommending statfileslevel, include blast-radius reasoning and one sibling-path non-impact check

5) Immutable vs Mutable File Boundaries

Do not propose edits in Adobe-managed immutable defaults. Keep changes in mutable include points (custom vhost/rewrite/filter/cache/renders/clientheaders files and enabled symlink targets).

When a recommendation would touch immutable files, return a compliant alternative using mutable includes.

6) AMS Preflight Verification (Core-7 + Host Check)

Minimum static evidence before sign-off:

1. validate({"config":"<changed dispatcher content>","type":"ams"})
2. lint({"mode":"directory","target":"<dispatcher src path>","strict_mode":true})
3. sdk({"action":"check-files","config_path":"<dispatcher src path>"})
4. sdk({"action":"diff-baseline","config_path":"<dispatcher src path>"}) for drift-sensitive changes

Runtime evidence when behavior changed:

• trace_request({"url":"<representative url>","config_path":"<dispatcher src path>"})
• inspect_cache({"url":"<representative cacheable url>","config_path":"<dispatcher src path>"})

Host syntax check when command access exists:

• httpd -t (or apachectl configtest)

7) Output Expectations For AMS Recommendations

Always include:

• explicit AMS assumption and affected tier (author/publish/livecycle)
• whether farm ordering or tier routing behavior changed
• variables affected (PUBLISH_*, AUTHOR_*, optional LIVECYCLE_*)
• flush ACL impact (/allowedClients) when invalidation paths are touched
• residual risk when runtime or host syntax checks were unavailable

Public References

• AMS dispatcher intro: https://experienceleague.adobe.com/en/docs/experience-manager-learn/ams/dispatcher/what-is-the-dispatcher
• AMS basic file layout: https://experienceleague.adobe.com/en/docs/experience-manager-learn/ams/dispatcher/basic-file-layout
• AMS config files: https://experienceleague.adobe.com/en/docs/experience-manager-learn/ams/dispatcher/explanation-config-files
• AMS variables: https://experienceleague.adobe.com/en/docs/experience-manager-learn/ams/dispatcher/variables
• AMS immutable files: https://experienceleague.adobe.com/en/docs/experience-manager-learn/ams/dispatcher/immutable-files
• AMS flushing: https://experienceleague.adobe.com/en/docs/experience-manager-learn/ams/dispatcher/disp-flushing
• AMS vanity URLs: https://experienceleague.adobe.com/en/docs/experience-manager-learn/ams/dispatcher/disp-vanity-url
• Dispatcher invalidation by folder level: https://experienceleague.adobe.com/en/docs/experience-manager-dispatcher/using/configuring/dispatcher-configuration#invalidating-files-by-folder-level
• Invalidating Dispatcher cache from AEM: https://experienceleague.adobe.com/en/docs/experience-manager-dispatcher/using/configuring/dispatcher-configuration#invalidating-dispatcher-cache-from-aem