If you want your job to start again in the Talend client i.e., the UI then try this
tInfiniteLoop (set some time) --------> tIterateToFlow --------> tRunJob
Where tRunJob is your sub job which does the input db connection and logic. This way even if your job (tRunJob) fails, it will loop back, wait for few seconds and re run the job again.
Hope this helps.
And why do you think your connection will fail anyways?