+state_retention_file=/var/cache/icinga/retention.dat
+
+
+
+# SYNC FILE
+# This is an advanced facility to pass a subset of retention
+# information into Icinga on a running system. This is similar
+# to the state retention file with the following difference:
+#
+# - if the last_check value is less than the current last_check,
+# then the state information is ignored (this must be specified
+# immediately after the object identifiers)
+#
+# - downtimes and comments are not identified by an id number, but
+# by other "similar characteristics". This is required to work in
+# a distributed Nagios environment
+# * downtimes: hostname, servicename (if appropriate), author,
+# comment, start_time, end_time, fixed, duration
+# * comments: hostname, servicename, author, comment
+#
+# If this variable is set, then on Icinga startup, the sync file
+# will be read after the retention file has been processed. If the
+# file is read successfully, it will be removed.
+# If the file does not exist, no error will appear.
+# There is also an API that will force a read of the sync file.
+
+#sync_retention_file=/var/cache/icinga/sync.dat