Upgrading Enterprise Manager Cloud Control from 13.5 to 24.1 - 3

This is the third post on upgrading EMCC from 13.5 to 24.1. Previous posts showed how to complete the pre-req work and upgrade the EM. This post shows how to upgrade the agents to 24.1. This post shows the steps for upgrading using EM Console.
To upgrade the central agent go to Setup -> Manage Enterprise Manager -> Upgrade Agents
This will open the agent upgrade console. Agent Upgrade Tasks tab will be selected. Under Agents for Upgrade click the Add button. This will open upgradeable agents box and select the 13.5 agents that will be upgraded. Once selected the agent details will be populated as shown below. It shows current version, version it will be upgraded to and the agent home.

Under the Choose credentails select "Preferred Privileged Credentials" (selected by default) even if no perferred credentails are available. This is not an issue as this privilege is needed to run the root.sh for agent upgrade. This could be done manually. This is also mentioned when the submit button is clicked. Click OK to continue with the upgrade.

Wait for upgrade job to complete successfully.

Agent upgrade results could also be viewd by clicking the job name available under "Agent Upgrade Results" page.

The agent will have a new home under agent base directory. It will have to be patched with latest RU that is relevant for the OMS+agent combination.

As the last step the old 13.5 agent home could be removed. This is done as a post agent upgrade task. Click on the cleanup agents and add the old 13.5 agent. It was noticed in multiple upgrades that the "installed version" for the old agent is listed as 24.1 even though correct 13.5 agent home is listed as the oracle home. Ignore this possible bug on the EM and continue with the 13.5 agent removal.

As before the agent removal progress could be monitored under job activity. Once complete view the results in cleanup-agent results page.

This concludes the upgrading of Enterprise Manager Cloud Control from 13.5 to 24ai.

Update 19th June 2026
EM systems that went through life cycle of starting as 13.4 and then upgraded to 13.5 followed by 24ai will see following error.

WARN - Ping communication error 
o.s.emSDK.agent.comm.exception.VerifyConnectionException [unable to connect to http server at https://:/empbs/upload. [handshake has no peer] 
javax.net.ssl.SSLHandshakeException [handshake has no peer] 
javax.net.ssl.SSLPeerUnverifiedException [peer not authenticated]

Reason is pre 13.4 SSL Cipher Suites. Refer KB639677 for the solution.

Related Posts
Upgrading Enterprise Manager Cloud Control from 13.5 to 24.1 - 1
Upgrading Enterprise Manager Cloud Control from 13.5 to 24.1 - 2
Upgrading Enterprise Manager Cloud Control from 13.4 to 13.5 - 1
Upgrading Enterprise Manager Cloud Control from 13.4 to 13.5 - 2
Upgrading Enterprise Manager Cloud Control from 13.4 to 13.5 - 3
Installing Enterprise Manager Cloud Control 13c (13.4)
Converting EM Repository DB from Non-CDB to PDB
Adding Targets on EM Cloud Control 13c
Installing Enterprise Manager Cloud Control 13c (13.3)
Installing Grid Control 11gR1 and Deploying Agents
Upgrading Grid Control 11g to 12c - 1

Useful MOS Docs
EM 24ai: Some Agents Fail to Communicate With OMS Post 24.1 Upgrade, Error: "handshake has no peer" KB639677