Check_MK Werk 7326: "Update DNS cache" action is now really cleaning up the cache

ID: 7326 Title: "Update DNS cache" action is now really cleaning up the cache Component: WATO Level: 2 Class: Bug fix Version: 1.6.0i1 As written in the documentation (https://mathias-kettner.com/cms_wato_hosts.html) Check_MK is keeping an internal DNS cache for the hosts that have configured no static IP address in Check_MK: --- With the host name method Check_MK uses cached data in order to minimise repeated DNS requests during an Activate Changes – which is very important for accelerating the activation procedure. Furthermore, the cache ensures that a changed configuration can still be activated if the DNS stops working. The catch is that Check_MK doesn't automatically notice the change to an address in DNS. For this reason, in the host details there is the button which deletes the entire DNS cache and forces a new resolution at the next Activate changes. This file is found under ~/var/check_mk/ipaddresses.cache in your instance, by the way. Deleting this file has the same effect as the button as described above. --- The problem was that previous versions did not really delete the entire cache, but only updated it. We have now changed this to make the cache invalidation work as intended.