The Overview Dashboard shows a high level summary of the MySQL instances and hosts that are monitored by MySQL Enterprise Monitor.
The Overview summarizes various key statistics related to the group that is selected, such Database Availability, Connections, Database Activity, Query Response Times, and any current MySQL Instances or Hosts that have active Critical or Emergency level events against them. It is designed in this way to give you a quick high level picture of assets that require immediate attention, as well as give you an up to date profile of how MySQL Instances within environment are behaving.
The Group Overview configuration bar enables you to define the default group to view in the Overview dashboard. It also enables you to define the period for which the data is displayed.
By default, the Group Overview is set to All. To edit the overview, click Edit. The Group Overview edit bar is displayed.
The controls in the Group Overview configuration bar are described in the following table:
Table 14.1. Group Overview Configuration
|Group Overview||Drop-down list containing all groups defined in MySQL Enterprise Service Manager.|
|Graph Time Range||Drop-down lists containing the time periods to apply to the graphs. The
possible values are:
Graph time ranges apply to the timeseries graphs, only. They do not apply to the Availability, Problem, or Current Emergency information.
|Go||Applies the new configuration to the Overview dashboard.|
|Save as Default||Sets the selected group and time range as the default.
It is not possible to save a date range, using From/To, as the default for a group.
|Reset||Resets the group overview configuration to the previously saved values.|
If the default group is deleted, an error is displayed on the Overview dashboard.
The Database Availability statistics show an aggregate of availability statistics, generated by the MySQL Availability Advisor, for all MySQL Instances within the selected Group, and allows you to monitor your Service Level Agreements for availability.
The MySQL Availability Advisor must be enabled for this functionality to work. It is enabled by default.
Database Availability is computed by each individual MySQL Enterprise Monitor Agent attempting to make a connection to each monitored MySQL Instance on a frequent basis (by default every 1 second, but this is configurable within the Advisor), to check whether the MySQL Instance is actively accepting new connections.
Depending on the response from the MySQL Instance, the availability is broken down in to four categories:
Available: The instance was actively monitored, and we could make a new connection.
Up: The instance
Uptime status variable reported it was up
when we last logged in, but we were not actively monitoring at
this time. This can happen when you start monitoring for the
first time from an Agent, or if the Agent was down for some
period of time.
Unreachable: The Agent could not get a
response from the MySQL Instance, however when we logged back
in we detected that the instance was up for that period of
time from the
Uptime status variable. This
can happen for various reasons, such as a
max_connections limit being reached, or
some networking problem between the MySQL Enterprise Monitor Agent and the
MySQL Instance that is being monitored.
Down: The Agent could not get a response from the MySQL Instance at all.
For each time range, the bar chart is split up in to slices of time (1 or 2 pixels each, depending on the width of the display), which represent a period of time; Day = 4 minutes, Week = 20 minutes and Month = 2 hours. Within those slices, the time within each availability state is aggregated across all MySQL Instances within the selected Group, and shown as the percentage of the total time in the slice.
For example, if you have four MySQL Instances within the selected group, with three of them being up and one of them being down for a 4 minute period within the day, the slice representing those 4 minutes would be 75% dark green, and 25% red.
MySQL Availability reporting is only available when using a MySQL Enterprise Monitor Agent of version 3.0.0 and above.
The remaining Databases Statistics graphs are designed to show a high level picture of the concurrency (Connections - All MySQL Instances), throughput (Database Activity - All MySQL Instances) and response times (Query Response Time Index) of the MySQL Instances within the selected group. These allow you to quickly spot if the profile of activity within the environment has changed.
For more information on the Query Response Time index (QRTI), see Section 23.2, “Query Response Time index (QRTi)”.
The Current Problem MySQL Instances and Current Problem MySQL Hosts list the top 5 MySQL Instances and Hosts respectively, based on whether they have open events with a current status of either Emergency or Critical.
The results are sorted by the total time that each event has been within these statuses, by Emergency descending, and then Critical descending. This means that the MySQL Instances, or Hosts, that have had Emergency, then Critical events open for the longest will float to the top of the list.
This is extremely useful in environments that are monitoring many MySQL Instances, as it allows you to focus in to which MySQL Instances or Hosts to tackle next, by telling you those that have the most problems against them.
When a MySQL Instance or Host has any open Emergency events against them, the row for that asset will be shown in red:
The Current Emergency & Critical Events panel lists a stream of the currently open events with an Emergency or Critical status. These are listed separately to the Current Problem MySQL Instances or Current Problem Hosts panels, as these might not show all assets within an environment that is monitoring five or more of either asset type.
This allows you to see all current high priority events within a single panel for all monitored assets.