Merge pull request #3302 from vespa-engine/hmusum/improve-config-prox…

…y-doc

Improve, clarify, fix config proxy documentation

en/operations-selfhosted/config-proxy.html

@@ -18,9 +18,8 @@
   so that all clients can ask for config on <em>localhost:19090</em>.
   The <em>config source</em> that the config proxy uses is set in
   <a href="/en/operations-selfhosted/files-processes-and-ports.html#environment-variables">VESPA_CONFIGSERVERS</a>
-  and may consist of one or more config sources
-  (usually <a href="/en/operations-selfhosted/configuration-server.html">config servers</a>,
-  but may be other config proxies).
+  and consists of one or more config sources
+  (the addresses of <a href="/en/operations-selfhosted/configuration-server.html">config servers</a>).
 </p><p>
   The proxy has a memory cache that is used to serve configs if it is possible.
   In default mode, the proxy will have an outstanding request to the config server
@@ -50,23 +49,23 @@
       <td>Serves config from memory cache only.
         Never uses a config source. A restart will lose all cached configs.
         Setting the mode to <em>memorycache</em> will make all applications on
-        the node work as before (given that they have previously been running,
+        the node work as before (given that they have previously been running
         and requested config), since the config proxy will serve config
-        from cache and work without any connection to the config server.
+        from cache and work without connection to any config server.
         Applications on this node will not work if the config proxy stops,
         is restarted or crashes.
       </td>
     </tr>
   </tbody>
 </table>
 <p>
-Interface with the config proxy using
-<a href="/en/operations-selfhosted/vespa-cmdline-tools.html#vespa-configproxy-cmd">vespa-configproxy-cmd</a> -
-run it without arguments to see usage.
-The tool displays heap usage for the proxy, displays the configs cached and flushes the cache.
-View the pending requests it has against the server(s).
-A pending request is the same as a subscription of server data,
-the requests are held open until the data changes on the server, through a <em>vespa activate</em>.
+Use <a href="/en/operations-selfhosted/vespa-cmdline-tools.html#vespa-configproxy-cmd">vespa-configproxy-cmd</a>
+to inspect cached configs, mode, config sources etc., there are also some commands to change some of the settings.
+Run the command as
+<pre>
+$ vespa-configproxy-cmd -m
+</pre>
+to see all possible commands.
 </p>