Checkmk Werk 13838: TCP fetcher: don't connect if no data is needed

ID: 13838 Title: TCP fetcher: don't connect if no data is needed Component: Checks & agents Level: 1 Class: Bug fix Version: 2.2.0i1 When fetching the data from a Checkmk agent (unix/windows), the fetcher would establish a connection before checking the cache file. If the cached data was still valid the connections has been closed. These "unused" connections could lead to unwanted agent executions or, in Checkmk 2.1, to irritating errors in the log of <tt>cmk-agent-ctl</tt> on the monitored host, such as <i>"Request failed: tls handshake eof"</i> or <i>"Request failed: Connection reset by peer (os error 104)"</i>.