Description of problem:

In code, we often swallow exceptions. There isn't any benefit (know to me), to do so.


Example from CommandsFactory:

catch (Exception ex) {
            log.error("An exception has occurred while trying to create a command object for command '{}' with parameters '{}': {}",
                    action.name(),
                    parameters,
                    ex.getMessage());
            log.debug("Exception", ex);
            return null;
        }

which will print this into log:

ERROR [org.ovirt.engine.core.bll.CommandsFactory] (default task-45) [0cf7f066-8328-4d77-a35f-dac2d37f058b] An exception has occurred while trying to create a command object for command 'RunVm' with parameters 'RunVmParams:{commandId='0625b1bb-8924-48eb-aa08-84e10f97fbb8', user='null', commandType='Unknown', vmId='43f269c7-5341-41de-894b-7205fbc23a3b'}': WELD-000049: Unable to invoke protected final void org.ovirt.engine.core.bll.CommandBase.postConstruct() on org.ovirt.engine.core.bll.RunVmCommand@55495ef8


Exception: java.lang.NullPointerException
	at org.ovirt.engine.core.bll.NestedCommandFactory.createWrappedCommand(NestedCommandFactory.java:24) [bll.jar:]
	at org.ovirt.engine.core.bll.PrevalidatingMultipleActionsRunner.initCommandsAndReturnValues(PrevalidatingMultipleActionsRunner.java:91) [bll.jar:]
…

which is both totally irrelevant and without problem. One has to enter debugging session to find out:

Caused by: org.postgresql.util.PSQLException: The column name pass_discard was not found in this ResultSet.

————————————————
Intent of this code is totally misleaded. It does not make logs any shorter, and instead of logging causing exception as ERROR, we log as error something which is totally fine. Every such:

log.error
log.debug
swallow

should disappear from code as it severely damages our logs.