Checkmk Werk 8780: mknotifyd: fix race condition in distributed setups

ID: 8780 Title: mknotifyd: fix race condition in distributed setups Component: Notifications Level: 2 Class: Bug fix Version: 1.7.0i1 In a distributed setup a slave site may try to deliver notifications locally during an activate changes even though the slave site should forward notifications to the master site. This effect appears when the option "Notification Spooling" is set to "Asynchronous local delivery by notification spooler" in the global settings and to "Forward to remote site by notification spooler" in the "Site specific global settings" of the slave site. This werk fixes this issue by locking the Checkmk configuration when a configuration snapshot is installed on the remote site. This way the "cmk --notify" command and the mknotifyd cannot use a partially installed Checkmk configuration. As a workaround the "Notification Spooling" can be set to "Forward to remote site by notification spooler" in the global settings and to "Asynchronous local delivery by Notification spooler" in the "Site specific global settings" of the slave site.