Decommissioning of AEM Servers

[SHIBANI06]

Hi,

We are analysing on decommissioning the Production servers but also wanted to check here for any pointers/tips to consider if we want to reduce the number of AEM Publisher and dispatcher servers in Production if someone has already worked on this before?

For ex: Out of 4 Publishers and 4 dispatchers, if we would want to reduce to 2 each as most of the sites are migrated to a different tool and we are just left with 8 out of 21 sites.

Thank you 

[SantoshSai]

Hi @SHIBANI06,

If you are planning to reduce the number of Publishers and Dispatchers in Production, there are a few important points to consider before scaling down:

1. Traffic & Load Analysis

   • Check your traffic patterns (page views, concurrent users, API calls) for the remaining 8 sites.

   • Run load tests on 2 publishers + 2 dispatchers to confirm they can handle peak loads comfortably.

2. Redundancy & HA

   • Moving from 4 → 2 publishers/dispatchers reduces fault tolerance. If one node goes down, you’ll only have 1 left.

   • Ensure your load balancer health checks and failover strategy are solid.

3. Content Publishing & Replication

   • Reconfigure Author replication agents to point to the new publisher list.

   • Check replication queue throughput during bulk publishes—2 publishers need to handle all traffic flushes now.

4. Dispatcher Configuration

   • Update your load balancer config when reducing dispatchers.

   • Validate cache hit ratio and invalidation rules to avoid bottlenecks.

   • Warm up cache after scale-down to reduce first-hit latency.

5. Monitoring & Alerts

   • Put strong monitoring in place for CPU, memory, GC, replication queues, and dispatcher cache health.

   • This is critical because fewer nodes mean less buffer if something spikes.

6. Disaster Recovery / Rollback Plan

   • Keep automation (CloudFormation, Ansible, etc.) ready so you can quickly scale back to 4 if needed.

   • Test the rollback before cutting servers.

7. License & Cost

   • Verify with Adobe if your license terms are per-core/instance and whether reducing infra affects compliance.

In short: Yes, you can scale down to 2 publishers + 2 dispatchers if your remaining 8 sites have much lower load. Just make sure you validate with load testing, have strong monitoring, and keep a fallback plan.

[SHIBANI06]

Thank you Santhosh

[SurenKo]

You'll should be okay as long as the website traffic load on the servers are not high, that is if the website usage is not high. Again this is a general question and also need to see what content is being served, regions, languages, APIs/integrations etc. need to be accounted for.

We did something similar for a static content website - but had high visits (sometimes).

• Run load tests on the lower env, that mimics Prod and see how the servers are performing.
• Then to reduce 1 set (1 Publish, 1 Dispatcher) to get the consensus on the load and response times. And decided accordingly.

  • 1 Author (shared across both blue and green environments)

  • 3 Publish instances - 2 active (blue live); 1 configured as a standby (green)

  • 3 Dispatcher instances - 2 active (blue - serving live traffic) and 1 standby (green - to take over during cutover or failover)

Ref: https://experienceleague.adobe.com/en/docs/experience-manager-cloud-manager/content/introduction#blu... following the same idea but for our on-premise.

[SHIBANI06]

Thank you but the AEM version being used is AEM 6.4

[SurenKo]

Technically, 6.4 should be similar.

On the version, you should consider upgrading - https://helpx.adobe.com/support/programs/eol-matrix.html