Support TiKV auto scaling-out by Storage

docs/api-references/docs.md

@@ -2756,21 +2756,13 @@ If not set, the default ScaleOutIntervalSeconds will be set to 300</p>
 <td>
 <code>metrics</code></br>
 <em>
-<a href="https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.13/#metricspec-v2beta2-autoscaling">
-[]Kubernetes autoscaling/v2beta2.MetricSpec
+<a href="#custommetric">
+[]CustomMetric
 </a>
 </em>
 </td>
 <td>
 <em>(Optional)</em>
-<p>metrics contains the specifications for which to use to calculate the
-desired replica count (the maximum replica count across all metrics will
-be used).  The desired replica count is calculated multiplying the
-ratio between the target value and the current value by the current
-number of pods.  Ergo, metrics used must decrease as the pod count is
-increased, and vice-versa.  See the individual metric source types for
-more information about how each type of metric must respond.
-If not set, the default metric will be set to 80% average CPU utilization.</p>
 </td>
 </tr>
 <tr>
@@ -2782,7 +2774,7 @@ string
 </td>
 <td>
 <em>(Optional)</em>
-<p>MetricsTimeDuration describe the Time duration to be queried in the Prometheus</p>
+<p>MetricsTimeDuration describes the Time duration to be queried in the Prometheus</p>
 </td>
 </tr>
 <tr>
@@ -3613,6 +3605,77 @@ CrdKind
 </tr>
 </tbody>
 </table>
+<h3 id="custommetric">CustomMetric</h3>
+<p>
+(<em>Appears on:</em>
+<a href="#basicautoscalerspec">BasicAutoScalerSpec</a>)
+</p>
+<p>
+</p>
+<table>
+<thead>
+<tr>
+<th>Field</th>
+<th>Description</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td>
+<code>MetricSpec</code></br>
+<em>
+<a href="https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.13/#metricspec-v2beta2-autoscaling">
+Kubernetes autoscaling/v2beta2.MetricSpec
+</a>
+</em>
+</td>
+<td>
+<p>
+(Members of <code>MetricSpec</code> are embedded into this type.)
+</p>
+<em>(Optional)</em>
+<p>metrics contains the specifications for which to use to calculate the
+desired replica count (the maximum replica count across all metrics will
+be used).  The desired replica count is calculated multiplying the
+ratio between the target value and the current value by the current
+number of pods.  Ergo, metrics used must decrease as the pod count is
+increased, and vice-versa.  See the individual metric source types for
+more information about how each type of metric must respond.
+If not set, the auto-scaling won&rsquo;t happen.</p>
+</td>
+</tr>
+<tr>
+<td>
+<code>leastStoragePressurePeriodSeconds</code></br>
+<em>
+int64
+</em>
+</td>
+<td>
+<em>(Optional)</em>
+<p>LeastStoragePressurePeriodSeconds is only for the storage auto-scaling case when the resource name in the metricSpec
+is <code>Storage</code>. When the Storage metrics meet the pressure, Operator would wait
+LeastStoragePressurePeriodSeconds duration then able to scale out.
+If not set, the default value is <code>300</code></p>
+</td>
+</tr>
+<tr>
+<td>
+<code>leastRemainAvailableStoragePercent</code></br>
+<em>
+int64
+</em>
+</td>
+<td>
+<em>(Optional)</em>
+<p>LeastRemainAvailableStoragePercent indicates the least remaining available storage percent compare to
+the capacity storage. If the available storage is lower than the capacity storage * LeastRemainAvailableStoragePercent,
+the storage status will become storage pressure and ready to be scaled out.
+LeastRemainAvailableStoragePercent should between 5 and 90. If not set, the default value would be 10</p>
+</td>
+</tr>
+</tbody>
+</table>
 <h3 id="dashboardconfig">DashboardConfig</h3>
 <p>
 (<em>Appears on:</em>
@@ -4971,6 +5034,7 @@ string
 </em>
 </td>
 <td>
+<em>(Optional)</em>
 <p>CurrentValue indicates the value calculated in the last auto-scaling reconciliation</p>
 </td>
 </tr>
@@ -4982,9 +5046,26 @@ string
 </em>
 </td>
 <td>
+<em>(Optional)</em>
 <p>TargetValue indicates the threshold value for this metrics in auto-scaling</p>
 </td>
 </tr>
+<tr>
+<td>
+<code>StorageMetricsStatus</code></br>
+<em>
+<a href="#storagemetricsstatus">
+StorageMetricsStatus
+</a>
+</em>
+</td>
+<td>
+<p>
+(Members of <code>StorageMetricsStatus</code> are embedded into this type.)
+</p>
+<em>(Optional)</em>
+</td>
+</tr>
 </tbody>
 </table>
 <h3 id="monitorcomponentaccessor">MonitorComponentAccessor</h3>
@@ -8813,6 +8894,86 @@ More info: <a href="https://kubernetes.io/docs/concepts/storage/persistent-volum
 </tr>
 </tbody>
 </table>
+<h3 id="storagemetricsstatus">StorageMetricsStatus</h3>
+<p>
+(<em>Appears on:</em>
+<a href="#metricsstatus">MetricsStatus</a>)
+</p>
+<p>
+<p>StorageMetricsStatus describe the storage metrics status in the last auto-scaling reconciliation</p>
+</p>
+<table>
+<thead>
+<tr>
+<th>Field</th>
+<th>Description</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td>
+<code>storagePressure</code></br>
+<em>
+bool
+</em>
+</td>
+<td>
+<em>(Optional)</em>
+<p>StoragePressure indicates whether storage under pressure</p>
+</td>
+</tr>
+<tr>
+<td>
+<code>storagePressureStartTime</code></br>
+<em>
+<a href="https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.13/#time-v1-meta">
+Kubernetes meta/v1.Time
+</a>
+</em>
+</td>
+<td>
+<em>(Optional)</em>
+<p>StoragePressureStartTime indicates the timestamp of the StoragePressure fist become true from false or nil</p>
+</td>
+</tr>
+<tr>
+<td>
+<code>availableStorage</code></br>
+<em>
+string
+</em>
+</td>
+<td>
+<em>(Optional)</em>
+</td>
+</tr>
+<tr>
+<td>
+<code>capacityStorage</code></br>
+<em>
+string
+</em>
+</td>
+<td>
+<em>(Optional)</em>
+</td>
+</tr>
+<tr>
+<td>
+<code>baselineAvailableStorage</code></br>
+<em>
+string
+</em>
+</td>
+<td>
+<p>BaselineAvailableStorage indicates the baseline for available storage size.
+This is calculated by the capacity storage size * storage auto-scaling baseline percent value
+If the AvailableStorage is less than the BaselineAvailableStorage, the database is under StoragePressure
+optional</p>
+</td>
+</tr>
+</tbody>
+</table>
 <h3 id="storageprovider">StorageProvider</h3>
 <p>
 (<em>Appears on:</em>

manifests/crd.yaml

@@ -13489,16 +13489,25 @@ spec:
                 metrics:
                   items:
                     properties:
+                      availableStorage:
+                        type: string
+                      baselineAvailableStorage:
+                        type: string
+                      capacityStorage:
+                        type: string
                       currentValue:
                         type: string
                       name:
                         type: string
+                      storagePressure:
+                        type: boolean
+                      storagePressureStartTime:
+                        format: date-time
+                        type: string
                       thresholdValue:
                         type: string
                     required:
                     - name
-                    - currentValue
-                    - thresholdValue
                     type: object
                   type: array
                 recommendedReplicas:
@@ -13518,16 +13527,25 @@ spec:
                 metrics:
                   items:
                     properties:
+                      availableStorage:
+                        type: string
+                      baselineAvailableStorage:
+                        type: string
+                      capacityStorage:
+                        type: string
                       currentValue:
                         type: string
                       name:
                         type: string
+                      storagePressure:
+                        type: boolean
+                      storagePressureStartTime:
+                        format: date-time
+                        type: string
                       thresholdValue:
                         type: string
                     required:
                     - name
-                    - currentValue
-                    - thresholdValue
                     type: object
                   type: array
                 recommendedReplicas: