Merge remote-tracking branch 'origin/master' into develop

docs/metrics-howto.rst

@@ -1,22 +1,27 @@
 How to monitor Synapse metrics using Prometheus
 ===============================================
 
-1: Install prometheus:
+1. Install prometheus:
+
    Follow instructions at http://prometheus.io/docs/introduction/install/
 
-2: Enable synapse metrics:
+2. Enable synapse metrics:
+
    Simply setting a (local) port number will enable it. Pick a port.
    prometheus itself defaults to 9090, so starting just above that for
    locally monitored services seems reasonable. E.g. 9092:
 
-  Add to homeserver.yaml
+   Add to homeserver.yaml::
 
      metrics_port: 9092
 
-  Restart synapse
+   Also ensure that ``enable_metrics`` is set to ``True``.
   
-3: Add a prometheus target for synapse. It needs to set the ``metrics_path``
-   to a non-default value::
+   Restart synapse.
+
+3. Add a prometheus target for synapse.
+
+   It needs to set the ``metrics_path`` to a non-default value::
 
     - job_name: "synapse"
       metrics_path: "/_synapse/metrics"
@@ -24,6 +29,11 @@ How to monitor Synapse metrics using Prometheus
         - targets:
             "my.server.here:9092"
 
+   If your prometheus is older than 1.5.2, you will need to replace 
+   ``static_configs`` in the above with ``target_groups``.
+   
+   Restart prometheus.
+
 Standard Metric Names
 ---------------------