Events are information that VividCortex has either detected or inferred about various parts of your system, such as hosts and queries. Events can be used to create Alerts.
Here are some examples:
- A disk becomes full or nearly full
- A server configuration variable changes
- A query returns an error to a client application
The Events dashboard is a powerful interactive feature for discovering timely information about systems, allowing you to swiftly filter, select, and drill down from a summary to details. To view the Events dashboard, click on “Health” in the left-hand navigation, then click “Events” at the top of the window.
Here is an overview of the dashboard:
You can use the toggles at the left to enable or disable events by severity (informational, warning, or critical). You can see a timeline of the number of events at the top of the page, as well as a category selector. In the main body of the page you see the events, with similar events grouped together.
Use the category selector to toggle display of various types of events:
After changing the category or severity selectors, the timeline shows the filtered subset of events in blue, with the total set of events in gray:
You can also click and drag on the timeline to select a subset of the time range. This selection is temporary and doesn’t update the time range in the top-right time selector. You can drag and resize it to filter events in realtime.
Events with similar messages are grouped together into rows in the main body of the page. Each row can represent one or many events. Clicking on a row expands it and lets you select the individual events contained within it to see their details. If a metric is associated with the event, you will see a sparkline chart of that metric over the time range in the time selector.
VividCortex generates events for a number of different things for your database, the OS that it is running on, and the functionality of the agent that monitors it. Below is a list of some of them, with an explanation of their meaning.
MySQL Server Stall
- This event, along with corresponding types for other supported databases, represents a Fault that VividCortex detected. Faults are short stalls that are usually caused by a bottleneck in the database’s workload. Refer to the Faults Page for details on how faults work.
High Distinct Query Rate
- This event indicates that we’ve received a very high number of unique query digests. Too many unique query digests prevents aggregation of data in a way that is meaningful. To continue providing useful data, we automatically adjust the digestion algorithm to be more aggressive, which allows the system to better detect queries which are similar to one another, with only small differences which affect digestion but not query behavior.
- This event indicates that a specific metric has exceeded a user-defined Threshold that was previously set for it. Metric Threshold events can be defined from the Alerts Tab in the Environment Setting Page.
New Important Query
- This event indicates that a previously unseen query has appeared among the top-10 queries in the environment. Similar to the New Important Process type.
New Important Process
- This event is similar to the New Important Query type - it indicates that a previously unseen process has appeared among the top-10 processes in the environment.
Database Connection Error
- This event is reported when the monitoring agent is unable to connect to the host database. For example, this can be because the address of the database is incorrect, the database is refusing connections, there is a problem with the agent’s configuration, or the database is down. When dealing with connection errors, please refer to the steps in our Troubleshooting guide or contact support for further assistance.
- This is a diagnostic event reporting an instance where one of our monitoring agent’s queries took longer than expected. When this happens, it can correspond to some metrics missing for a few seconds on the affected host.
Query Samples Unavailable
- This event indicates that a database host’s configuration does not allow the VividCortex agent to collect samples of queries that ran on the host. This is only applicable for hosts that are using the off-host monitoring configuration.
MySQL Open Tables Tracking Stopped
- This event indicates that a database has more open tables than the agent is configured to track, so table tracking has been disabled to prevent any potential performance problems. By default the agent will capture metrics on the open tables that MySQL is using, but since doing so is expensive this monitoring is automatically disabled if too many tables are open. If you would like these metrics enabled contact support for assistance in changing the limit.
MySQL Replication Started
- This event indicates that the VividCortex agent has detected that replication has started running
for a replica database. The event will specify whether
START SLAVEwas seen when replication started.
MySQL Replication Stopped
- This event indicates that the VividCortex agent has detected that replication has stopped running
for a replica database. The event will specify whether
STOP SLAVEwas seen when replication stopped.
Intermittent Connectivity to Datacenter!
- This is a diagnostic event reporting an instance where the VividCortex agent experienced a connection timeout while attempting to report metrics to the VividCortex API. If this event shows up in your environment, it could indicate a problem that will lead to missing data in your environment if not addressed.
Host stopped sending data
- This is a diagnostic event that is generated by VividCortex’s API. It indicates that the API has not received any new metrics from a registered host in the last 15 minutes. This can be caused by connection problems, or a host being shutdown.
Database Server Restart
- This event indicates that the database being monitored by VividCortex has been restarted.
Database Configuration Change
- This event indicates that the VividCortex agent detected a change in the configuration of the database being monitored. The agent will detect runtime configuration changes as well as changes applied after a database is restarted.
- This event indicates that the agent attempted to register a new database host and failed. This can be because there are no licenses available for the new database, or because of a failure in the API.
- This event indicates a VividCortex agent has started running. The event reports the specific agent that started, along with its version.
- This event indicates a VividCortex agent has stopped running. The event reports the specific agent that stopped, and also reports the manner in which it was stopped (e.g. graceful shutdown or a process kill).