RDoc-2948 & RDoc-2949 Add the Cluster Health section to Cloud -> Main…

…tenance & Troubleshooting

Documentation/4.2/Raven.Documentation.Pages/cloud/cloud-maintenance-troubleshooting.markdown

@@ -25,4 +25,80 @@ status.
 | Low uptime - below 12 hours   | Product's uptime has been below 12 hours for at least 24 hours.                                                                                                                                                                                                                                                                   |
 | Low uptime - below 48 hours   | Product's uptime has been below 48 hours for at least 96 hours.                                                                                                                                                                                                                                                                   |
 
+{PANEL/}
+
+{PANEL: Cluster Health}
+
+**Cluster Health** helps keep your cluster healthy by providing suggestions and incidents history.  
+This dashboard has two separated sections:
+
+- [Incidents History](cloud-maintenance-troubleshooting#incidents-history)
+- [Suggestions](cloud-maintenance-troubleshooting#suggestions)
+
+---
+
+## Incidents History
+
+The *RavenDB Cloud* monitoring system tracks incidents and cluster performance.  
+This section lets you analyse your cluster incidents for a selected *time period*, *cluster node*, *severity* and *category*.
+
+!["Cluster Health: Incidents History section"](images\cluster-health-incidents-history.png "Cluster Health: Incidents History section")
+
+#### Categories and their descriptions
+
+Incidents are split into *six* categories. **Description** column contains additional information about the incidents.  
+
+| Category name | Description                                                                            |
+|---------------|----------------------------------------------------------------------------------------|
+| Uptime        | Product's uptime has been below a specified time.                                      |
+| Memory        | Product is running low on available memory.                                            |
+| CPU           | Product is running low on CPU credits or experiencing a high level of CPU utilization. |
+| Disk          | Product's available disk space is low.                                                 |
+| IO            | Product is experiencing high input/output operations.                                  |
+| Availability  | Product is currently not responding to input or commands or has been restarted.        |
+
+---
+
+## Suggestions
+
+This section displays suggestions for a selected *cluster node* based on incident trends.
+
+!["Cluster Health: Suggestions section"](images\cluster-health-suggestions.png "Cluster Health: Suggestions section")
+
+Suggestions are generated based on a 60-day period divided in half.  
+
+**First period** (hereinafter referred to as **previous period**) lasts from `now - 60 days` to `now - 30 days`.  
+**Second period** (hereinafter referred to as **current period**) lasts from `now - 30 days` to `now`.  
+
+#### Suggestion types
+
+**Cluster Health** is able to generate suggestions for *five* usage areas:
+
+- High CPU usage                                                         
+- High IO usage                        
+- Low memory mode                      
+- Low CPU credits                                                                      
+- Server restarted due to Out of Memory
+
+#### Analyses
+
+Suggestions are generated using three types of analyses for specific suggestion types:
+
+| Analyse type                                     | Applicable to                                                   | Description                                                                                                 |
+|--------------------------------------------------|-----------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------|
+| Current period above previous period by percents | High CPU usage, High IO usage, Low memory mode, Low CPU credits | The duration of a specific event was longer in the current period than in the previous period.              |
+| Current period above previous period by numbers  | Server restarted due to Out of Memory                           | The number of occurrences of a specific event was higher in the previous period than in the current period. |
+| Current period above threshold by percents       | High CPU usage, High IO usage, Low memory mode, Low CPU credits | The duration of a specific event in the current period was longer than the threshold (5%).                  |
+
+Below examples of the suggestions with the analyses: 
+
+!["Cluster Health: An example of `Current period above previous period by percents` analyse"](images\cluster-health-suggestions-current-month-above-previous-month-by-percents.png "Cluster Health: An example of `Current period above previous period by percents` analyse")
+
+
+!["Cluster Health: An example of `Current period above previous period by numbers` analyse"](images\cluster-health-suggestions-current-month-above-previous-month-by-numbers.png "Cluster Health: An example of `Current period above previous period by numbers` analyse")
+
+
+!["Cluster Health: An example of `Current period above threshold by percents` analyse"](images\cluster-health-suggestions-current-month-above-threshold-by-percents.png "Cluster Health: An example of `Current period above threshold by percents` analyse")
+
+
 {PANEL/}