Check_MK Werk 5535: Check_MK hosts can now use multiple agents

ID: 5535 Title: Check_MK hosts can now use multiple agents Component: Core & setup Level: 2 Class: New feature Version: 1.5.0i2 It is now possible to configure multiple Check_MK agents for a single host. With this change, you can now configure e.g. a ESX VCenter to use the ESX special agent together with the regular Check_MK agent installed on the monitored host. All existing hosts remain using their existing configuration after an update. Also new hosts only use a single Check_MK agent using the already existing logic where a) The Check_MK agent was contacted via TCP or b) a configured data source program (special agent or other program invocation) was used. The new feature can be enabled by changing the host attribute (on hosts or folders) "Check_MK Agent" to e.g. "Contact Check_MK agent and all datasource programs". This will make Check_MK use all data sources matching on this host instead of just picking the first matching one. There is also an alternative option "Use all enabled datasources" available which can be used to execute only the data sources matching the host. On the way to this change we have changed server previously existing things: <ul> <li>The host tag group <tt>agent</tt> has been split into multiple tag groups to be more flexible.</li> <li>The tag group <tt>ping</tt> and <tt>snmp</tt> have been added and provide the options which were previously available in the single <tt>agent</tt> attribute.</li> <li>All these tag groups are treated as <i>builtin</i> tag groups defined by Check_MK (can not be modified anymore).</li> <li>Existing configurations of hosts/folders will be translated seamlessly into the new format.</li> <li>During updates your site will only apply the changes above in case you have an unmodified <tt>agent</tt> tag group. In case you have modified it in any way, these changes will not be applied and you won't be able to use the changes introduced with this werk. You will then have to clean up your local changes. Once you delete your local tag group "agent", the builtin one will be used automatically.</li> <li>The <i>Edit host</i> dialog has split up into more independent sections, the new ones are <i>Address</i> and <i>Data sources</i> to better visualize the relation of the different attributes.</li> </ul> <i>Please note:</i> In case you are using the Web-API calls to create or modify hosts or folders while setting attributes we changed with this change, you may have to change your API calls.