[Exist-open] Full backup at 4 a.m.

[Christian A. <chr...@ge...>]

Dear all,

I have a backup scheduler running that creates 6 backups per day, 5 
incremental and 1 full backup.

The code in my etc/conf.xml looks like this:

         <job type="system" name="backup"
class="org.exist.storage.ConsistencyCheckTask"
                         cron-trigger="0 0 0/4 * * ?">
                 <parameter name="output" 
value="/opt/server/ediarum/exist-db_5.2.0/backup"/>
                 <parameter name="backup" value="yes"/>
                 <parameter name="incremental" value="yes"/>
                 <parameter name="incremental-check" value="no"/>
                 <parameter name="max" value="6"/>
         </job>

Here is my problem:

I want the full backup to be created at 4:00 a.m. I consulted the eXist 
online documentation and the book and assumed that 0 0 0/4 would be 
translated to: every 4 hours starting at midnight with the first backup 
being a full backup.

But in reality, the full backup is created at 8:00 a.m. My experience 
during several months showed that this time even differs. Sometimes, the 
full backup was created at 4 p.m. oder at noon - maybe depending in the 
time when the eXist-db ws started.

What am I doing wrong? How can I improve this scheduler to have a full 
backup at 4 a.m. while keeping the 5 incremental backups during the day?

Thanks in advance and kind regards

Christian