You may want to sequentially run multiple sync sets between the same servers. In that case, osync-batch.sh is a nice tool that will run every osync conf file, and, if a task fails,
run it again if there's still some time left.
The following example will run all .conf files found in /etc/osync, and retry 3 times every configuration that fails, if the whole sequential run took less than 2 hours.