Publishing & Replication
You have built pages and assets on the author instance. Visitors never see the author tier - they see the publish tier, fronted by the Dispatcher and a CDN. Replication (also called publishing or activation) is the process that copies content from author to publish.
Activation and deactivation
| Action | Effect |
|---|---|
| Activate (Publish) | Copy the page/asset to publish and make it live |
| Deactivate (Unpublish) | Remove the page/asset from publish |
| Delete | Remove from author; deactivate first so it also leaves publish |
Authors activate from the Sites console (select page > Publish), from the page editor (Page Information > Publish Page), or in bulk via Manage Publication (which also handles references and scheduling).
Publishing references
A page usually depends on other content: images in the DAM, Experience Fragments, Content Fragments,
tags, and the template/policies in /conf. Publish the references too, or the page renders broken
on publish. The Manage Publication wizard surfaces references so you can include them; for
programmatic publishing you must enumerate and replicate them yourself.
Scheduling (on/off time)
Use Manage Publication > Later to schedule activation/deactivation. On Time / Off Time only show or hide a page that is already published; they do not publish or unpublish it.
How replication works under the hood
On AEM 6.5, replication is driven by replication agents (configured at
/etc/replication/agents.author). The default Agent on author sends activated content to publish;
Dispatcher Flush agents invalidate the Dispatcher cache after publish.
On AEM as a Cloud Service, the classic agent model is replaced by Sling Content Distribution (SCD) and a managed pipeline - you do not configure replication agents. Content authored on the author service is distributed to the publish service through Adobe-managed infrastructure, and the publish tier invalidates its Dispatcher cache automatically; the CDN is not flushed and serves cached copies until their TTL expires.
| AEM 6.5 | AEM as a Cloud Service | |
|---|---|---|
| Mechanism | Replication agents | Sling Content Distribution (managed) |
| Configuration | /etc/replication/agents.* | None - Adobe-managed |
| Cache flush | Dispatcher Flush agent | Automatic Dispatcher invalidation; CDN expires by TTL |
| API | Replicator | Replicator (still works) |
"Replication agent" is 6.5/AMS vocabulary. On AEMaaCS you will hear "content distribution". The
authoring actions (Activate/Deactivate) and the Replicator API are the same on both.
Publishing programmatically
The com.day.cq.replication.Replicator service activates or deactivates a path. This works on both
6.5 and AEMaaCS:
import com.day.cq.replication.ReplicationActionType;
import com.day.cq.replication.ReplicationException;
import com.day.cq.replication.Replicator;
import javax.jcr.Session;
import org.apache.sling.api.resource.ResourceResolver;
import org.osgi.service.component.annotations.Reference;
@Reference
private Replicator replicator;
public void publish(ResourceResolver resolver, String path) throws ReplicationException {
Session session = resolver.adaptTo(Session.class);
if (session == null) {
throw new ReplicationException("Could not adapt ResourceResolver to a JCR Session");
}
replicator.replicate(session, ReplicationActionType.ACTIVATE, path);
}
For bulk or ad-hoc publishing, the Groovy Console has a ready-made activation script. For deeper coverage - tree activation, agents, and the full API -- see the Replication & Activation reference.
After publish: flushing the cache
Publishing updates the publish repository, but visitors hit the Dispatcher (and CDN) cache. A
stale cache means visitors keep seeing old content. On 6.5 a Dispatcher Flush agent invalidates the
affected paths; on AEMaaCS Dispatcher invalidation is automatic, while the CDN expires content by TTL. See
Dispatcher & Caching for cache rules and statfileslevel.
Troubleshooting
| Symptom | Likely cause | Fix |
|---|---|---|
| Page activated but not live | Dispatcher/CDN serving a cached copy | Flush the path; verify the flush agent (6.5) |
| Broken images on publish | Referenced asset not published | Re-publish with Manage Publication including references |
| Replication queue blocked | Publish unreachable, bad credentials, or a poison item | Open the agent (6.5), clear/retry the queue, check the publish receiver |
| Page reappears after delete | Deleted on author without deactivating | Deactivate first, then delete |
| Works on author, 404 on publish | Page or its template/policy not published | Publish /conf template + the page |
On 6.5 inspect queues at Tools > Deployment > Replication or the agent's Test Connection / View Queue. On AEMaaCS use Tools > Deployment > Distribution (agent status, logs, and queue).
Summary
You learned:
- Replication copies content from author to publish; activate/deactivate are the core actions
- Always publish references (assets, fragments, tags,
/conf) along with a page - Scheduling with on/off time and Manage Publication
- AEM 6.5 uses replication agents; AEMaaCS uses managed Sling Content Distribution
- The
ReplicatorAPI publishes programmatically on both platforms - Publishing must be followed by a cache flush for visitors to see changes
- How to diagnose a blocked queue and broken references
Official Documentation
Next up: Workflows - automating content operations with workflow models, launchers, and custom process steps.