Update config docs to reference new Prometheus metrics provider.

docs/configuration/README.md

@@ -14,6 +14,7 @@ The Sherpa server can be configured by supplying either CLI flags or using envir
 * `--log-format` (string: "auto") - Specify the log format ("auto", "zerolog" or "human").
 * `--log-level` (string: "info") - Change the level used for logging.
 * `--log-use-color` (bool: true) - Use ANSI colors in logging output.
+* `--metric-provider-prometheus-addr` (string: "") The address of the Prometheus endpoint in the form <protocol>://<addr>:<port>.
 * `--policy-engine-api-enabled` (bool: true) - Enable the Sherpa API to manage scaling policies.
 * `--policy-engine-nomad-meta-enabled` (bool: false) - Enable Nomad job meta lookups to manage scaling policies.
 * `--policy-engine-strict-checking-enabled` (bool: true) - When enabled, all scaling activities must pass through policy checks.

docs/configuration/telemetry.md

@@ -278,16 +278,10 @@ Autoscale metrics allow operators to get insight into how the autoscaler is func
     <td>Summary</td>
   </tr>
   <tr>
-    <td>`sherpa.autoscale.evaluation.error`</td>
-    <td>Number of autoscaling evaluation errors across all jobs</td>
-    <td>Number of errors</td>
-    <td>Counter</td>
-  </tr>
-  <tr>
-    <td>`sherpa.autoscale.{job}.evaluation.error`</td>
-    <td>Number of autoscaling evaluation errors for the job named {job}</td>
-    <td>Number of errors</td>
-    <td>Counter</td>
+    <td>`sherpa.autoscale.{job}.{group}.evaluation`</td>
+    <td>The time taken to perform the autoscaling evaluation for the job named {job} and group named {group}</td>
+    <td>Milliseconds</td>
+    <td>Summary</td>
   </tr>
   <tr>
     <td>`sherpa.autoscale.trigger.error`</td>
@@ -313,4 +307,22 @@ Autoscale metrics allow operators to get insight into how the autoscaler is func
     <td>Number of successes</td>
     <td>Counter</td>
   </tr>
+  <tr>
+    <td>`sherpa.autoscale.prometheus.get_value`</td>
+    <td>The time taken to query Prometheus for a metric value</td>
+    <td>Milliseconds</td>
+    <td>Summary</td>
+  </tr>
+  <tr>
+    <td>`sherpa.autoscale.prometheus.error`</td>
+    <td>Number of errors querying Prometheus for a metric value</td>
+    <td>Number of errors</td>
+    <td>Counter</td>
+  </tr>
+    <tr>
+      <td>`sherpa.autoscale.prometheus.success`</td>
+      <td>Number of successful queries of Prometheus for a metric value</td>
+      <td>Number of successes</td>
+      <td>Counter</td>
+    </tr>
 </table>