I have strange problem with pentaho-server schedules:

I have several tens of schedules running daily generating different files and sending them via mail. However, some of them do not run properly, or better say, do not run at all every now and then. It is not often however, from all schedules I have, there is like one in month or 2 months that does not run, but its starting to be annoying with increades numbers of schedules.

For example, there is schedule executing *.prpt report and sending its resut via mail. It is set to run daily, running since 1. January 2018. But no mail was received on 2.April.2018 and 9.April.2018. However all other days before and after those 2 exceptions, since 1. January 2018, schedule was executed and mail delivered.

I was trying to get some clues why is that, however I am not able to find any logs regarding executing schedules in pentaho-server. Checked all log files in pentaho-server/tomcat/logs but wasn't able to find any clue. Also was looking for location of other logs, but couldn't find anything.

Can someone please give me hint where to look for such logs. Or should I first enable them, or configure somewhere?

Thanks in advance