Processes in Instance: <<>>
---------------------------------+--------------------+---------+---------
ias-component                    | process-type       |     pid | status
---------------------------------+--------------------+---------+---------
OC4JGroup:admin_group            | OC4J:admin_apps    |  241672 | Alive
ASG                              | ASG                |     N/A | Down
OC4JGroup:default_group          | OC4J:oc4j_soa      |  409618 | Alive
OC4JGroup:default_group          | OC4J:home          |  340092 | Alive
HTTP_Server                      | HTTP_Server        |  462964 | Down

The command opmnctl startproc ias-component=HTTP_Server resulted in:

Error
--> Process (pid=13365)
failed to start a managed process after the maximum retry limit

The log file /opmn/logs/HTTP_Server~1.log. Was not very helpfull:

--------
09/08/19 10:25:37 Start process
--------
ORACLE_HOME/Apache/Apache/bin/apachectl startssl: execing httpd

After a lot of Google, OTN and searching on our server we found out that the owner and rights for the .apachectl somehow got lost during the back up (compression?) or restore operation. On UNIX the HTTP server should run as root. Changing the ownership and rights as described in the link solved our problem:

• Change to root user
• Navigate to ORACLE_HOME/Apache/Apache/bin and execute the following command:
• chown root .apachectl
• chmod 6750 .apachectl
• Exit root.