AGENT_BLOCKED: Agent is out-of-sync with repository. - How to unblock the agent?

Este error para por fallo de conexión entre el Cloud Control 12c y el host destino por algún inconveniente de red dejan de estar sincronizados y por ello aparece en la consola de administración como desconocido.

Problema

Realizamos todos los pasos que a primera vista fuesen suficientes para solventar el inconveniente que son:

1. Bajar el agente en el host destino

bash-4.2$ ./emctl stop agent
Oracle Enterprise Manager Cloud Control 12c Release 2
Copyright (c) 1996, 2012 Oracle Corporation.  All rights reserved.
Agent is Not Running

2. Setiar nuevamente la contraseña del agente

bash-4.2$ ./emctl secure agent
Oracle Enterprise Manager Cloud Control 12c Release 2
Copyright (c) 1996, 2012 Oracle Corporation.  All rights reserved.
Agent is already stopped...   Done.
Securing agent...   Started.
Enter Agent Registration Password :
EMD gensudoprops completed successfully
Securing agent...   Successful.

3. Verificar el estado actual del agente

bash-4.2$ ./emctl status agent
Oracle Enterprise Manager Cloud Control 12c Release 2
Copyright (c) 1996, 2012 Oracle Corporation.  All rights reserved.
---------------------------------------------------------------
Agent is Not Running

4. Subir el agente en el host destino

bash-4.2$ ./emctl start agent
Oracle Enterprise Manager Cloud Control 12c Release 2
Copyright (c) 1996, 2012 Oracle Corporation.  All rights reserved.
Starting agent ..................... started.
bash-4.2$ ./emctl status agent
Oracle Enterprise Manager Cloud Control 12c Release 2
Copyright (c) 1996, 2012 Oracle Corporation.  All rights reserved.
---------------------------------------------------------------
Agent Version     : 12.1.0.2.0
OMS Version       : (unknown)
Protocol Version  : 12.1.0.1.0
Agent Home        : /u01/app/agent12c/agent_inst
Agent Binaries    : /u01/app/agent12c/core/12.1.0.2.0
Agent Process ID  : 33685686
Parent Process ID : 22020106
Agent URL         : https://Toachi.senplades.int:3872/emd/main/
Repository URL    : https://palmar.senplades.int:4901/empbs/upload
Started at        : 2014-10-21 12:30:45
Started by user   : usrsogr
Last Reload       : (none)
Last successful upload                       : (none)
Last attempted upload                        : 2014-10-21 12:30:59
Total Megabytes of XML files uploaded so far : 0
Number of XML files pending upload           : 808
Size of XML files pending upload(MB)         : 9.36
Available disk space on upload filesystem    : 21.96%
Collection Status                            : Collections enabled
Heartbeat Status                             : Agent is blocked
Last attempted heartbeat to OMS              : 2014-10-21 12:30:59
Last successful heartbeat to OMS             : (none)
Next scheduled heartbeat to OMS              : 2014-10-21 12:33:59

---------------------------------------------------------------
Agent is Running and Ready

5. Subir el agente al servidor Cloud Control

bash-4.2$ ./emctl upload agent
Oracle Enterprise Manager Cloud Control 12c Release 2
Copyright (c) 1996, 2012 Oracle Corporation.  All rights reserved.
---------------------------------------------------------------
EMD upload error:full upload has failed: The agent is blocked by the OMS. Agent is out-of-sync with repository. This most likely means that the agent was reinstalled or recovered. Please contact an EM administrator to unblock the agent by performing an agent resync from the console. (AGENT_BLOCKED)


Al momento de realizar el upoload nos indica que el agente esta bloqueado en el Cloud Control.

Solución

A continuación se detalla los pasos para poder solventar este inconveniente.

Desbloquear agente desde el Cloud Control

1. Pantalla principal: Elegir agentes

 2. Seleccionar los desconocidos

3. Seleccionar el agente a reparar

4. Seleccionar Agent >>Resynchonization 

Nota: Se puede observar que un proceso esta en ejecución y puede tardar varios minutos, una vez finalizada la actividad automáticamente el Host ya es accesible.