Monitoring MarkLogic Guide — Chapter 3

Overview

The Monitoring History feature allows you to capture and view critical performance data from your cluster. Once the performance data has been collected, you can view the data in the Monitoring History page. The top-level Monitoring History page provides an overview of the performance metrics for all of the key resources in your cluster. For each resource, you can drill down for more detail. You can also adjust the time span of the viewed data and apply filters to view the data for select resources to compare and spot exceptions.

By default, the performance data is stored in the Meters database. Monitoring History capture is enabled at the group level. Typically you have one group per cluster. You can also configure a consolidated Meters database that captures performance metrics from multiple groups. The group configuration defines which database is used to store performance metrics for that group (defaulting to a shared Meters database per cluster), as well as all configuration parameters for performance metrics, such as the frequency of data capture and how long to retain the performance data. The Meters database can participate in all normal database replication, security, and failover operations.

Enabling Monitoring History on a Group

In order to collect monitoring history data for your cluster, you must enable performance metering for your group.

1. Log into the Admin Interface.
2. Click the Groups icon on the left tree menu.
3. Locate the Performance Metering Enabled field toward the bottom of the Group Configuration page and click on true.

   

   You can configure the parameters for collecting monitoring history, as described in the table below.

   Parameter	Description
   meters database	The database in which performance monitoring history and usage metrics documents are stored. By default, historical performance and usage metrics are stored in the Meters database.
   performance metering period	The performance metering period, in minutes. Performance data is collected at each period. The period can be any value of 1 minute or more. If you are collecting monitoring history for multiple groups, you should either set the same period for each group or configure your filter to view the history data for one group at a time.
   performance metering retain raw	The number of days raw performance monitoring history data is retained. See Setting the Monitoring History Data Retention Policy for details.
   performance metering retain hourly	The number of days hourly performance monitoring history data is retained. See Setting the Monitoring History Data Retention Policy for details.
   performance metering retain daily	The number of days daily performance monitoring history data is retained. See Setting the Monitoring History Data Retention Policy for details.

Setting the Monitoring History Data Retention Policy

The retention policy (for raw, hourly, daily) is a value set in days. If performance metering is enabled, then all data that is older than that many days for the specified period (raw, hour, day) is deleted. The retention policy is set at a group level, so different groups can have different retention policies. For example, GroupA may have raw set to 1 day and GroupB may have raw set to 10 days. The cleanup code follows this retention value on a per-group basis.

There are cases where metering data may become orphaned, so it may no longer belong to an existing group. Some examples of when this could occur are:

• Deleting a group
• Importing metering data from another cluster

Any metering data that no longer belongs to any active group in the current cluster is deleted. To avoid this, turn off metering or avoid deleting groups and instead move hosts out of the group but keep the group in the cluster configuration.

Loading older Monitoring History data (for example, by restoring a backup of the Meters database) will be immediately affected by data retention policy. So, you should turn off perfomance metering prior to restoring any data that is older than the time specified by your retention policy.

Deletion of data older then the retention policy occurs no sooner than the retention policy, but may, for various reasons, still be maintained for an unspecified amount of time.

Changing the retention policy from smaller to larger values does not restore data that has already been deleted.

The default data retention policy settings are as shown in the table below. To maximize efficiency, it is a best practice to retain raw data for the least number of days and the daily data for the most number of days.

Viewing Monitoring History

You can display the Monitoring History by doing the following:

1. Open a browser and enter the URL:

   http://monitor-host:8002/

   where monitor-host is a host in the cluster you want to monitor

2. At the top of the page, click on Monitoring and click on History in the pull-down menu:

   

3. The Monitoring History page appears. From the Monitoring History Overview page, you can navigate to any of the pages described in this chapter.

Each line in a chart represents a metric for the resource. In the Overview page, the lines represent an aggregate of the metrics for all of the cluster resources. In each Details page, the lines represent the metric for each specific resource.

Each point on a line represents a period in which the performance data was captured. Hovering over a chart point displays the name of the resource metric, along with the performance value for the metric at that point in time.

The displayed metrics (in MegaBytes per second) are color coded. You can display a legend that indicates which colors represent which metrics by clicking on the red dot in the upper right-hand section of the graph. To close the legend, click on the ‘x' in the upper right-hand portion of the legend window.

To simplify the view of charts on a page, you can collapse a chart or a group of charts for a resource by clicking on the triangle in the upper right-hard portion of the chart or chart group.

To expand a collapsed chart view, click on the triangle in the upper right-hard portion of the collapsed chart.

Viewing Monitoring History by Time Span and Frequency

As described in Enabling Monitoring History on a Group, the frequency in which performance metrics are captured is configurable, in minute intervals. The snapshots of performance metrics for each host are rolled up into a summary document that contains aggregate calculations on the values for that host.

You can configure your view of the captured performance data by time span and frequency.

The Time Span settings are located in the upper left-hand corner of the Monitoring History page.

There are three basic settings you can adjust to control how the data is displayed:

• A date/time range, down to the granularity of a minute, that determines the time span of the displayed data. (By default, this is the last 24 hours.)
• A period interval that determines the frequency of the displayed data. The possible intervals are shown in the following table.

  Period	Description
  Raw	Display the performance data just as it was captured with the set frequency.
  Hour	Display the performance data, in aggregate form, per hour. (This is the default.)
  Day	Display the performance data, in aggregate form, per day.

You can 'zoom in' to display part of the timespan by selecting the begin time of your 'zoom' on any chart and click and hold your left mouse button and drag it to the end 'zoom' time. The selected timeframe is highlighted and the zoomed-in time is displayed for all of the charts in the page. Navigating to another Monitoring History page resets all of the charts to the timespan selected in the TIME SPAN panel.

After changing either the time span and/or the period, click on refresh to display the updated charts. Clicking refresh will also update any changes you've made to the Filters settings. For details about filters, see Filtering Monitoring History by Resources. If you have zoomed into a portion of a timespan, refresh will redisplay the charts using the timespan selected in the TIME SPAN panel.

You can use the Shortcut links to display either the last hour, day or 30 days of performance data. Selecting a Shortcut link will automatically refresh the displayed charts.

Each Shortcut also sets the Period value, as shown in the table below.

Labeling Monitoring History Time Spans

You can use the Label feature to capture and tag metrics for the set time span. You can store any number of labels. These labels can be used to identify events, instances, and periods of time. Labels can be added, updated or deleted at any time. Labels themselves are not stored with the raw metric data. They are only used for reporting purposes.

1. To create a label for your current view of the Monitoring History data, select New Label from the Label pull-down menu.

   

2. In the Create a New Label popup window, the name of the label is the time span of the currently displayed charts, by default.

   

3. You can keep the default name for the label, or change it to be more descriptive. Click Save.

   

4. You can edit your label names or delete labels by selecting Edit Labels from the Labels pull-down menu.

   

5. In the Edit Labels popup window, you can either edit the label name or delete the label. To delete a label, hover over the label and a click on the garbage can icon to the right. When finished editing, click Close.

   

   If you edit a label and, before closing the Edit Labels window, decide not to save your edits, press the Esc key to terminate the edits and keep the original labels.

6. You can view all of the labels that have data within the currently selected timespan by clicking on the triangle to the right of the Labels section at the top of the Monitoring History page to expand the Labels chart.

1. Each label appears as a timeline. Hover over a timeline to display the label name. Click on a timeline to update the view to the time span associated with the label. Selecting a timeline is functionally equivalent to selecting a label from the Label menu in that it updates the view with the start and end times in the TIME SPAN panel.

If your labeled data has been purged from the Meters database, as the result of the retention policy or some other reason, the label will remain but there will be no data associated with that label.

1. You can click on the label icon at the top right-hand portion of the page to create a label for the currently displayed time span. Follow the same procedure as described in steps 2 and 3 to finish creating the label.

If the data for a label does not fall within the currently displayed timespan, the label will not be displayed in the Labels chart. To display the charts for such labels, select the label from the Label pull-down menu.

Filtering Monitoring History by Resources

You can set filters for select resources to display only the stored performance metrics for those resources. You can filter by groups and databases. And in each group, by hosts and servers. By default, the metrics for all of the resources in the cluster are displayed.

Filter types that are active for the current view have headings highlighted in blue. For example, on the Overview page, all filters are active while on the Databases Detail view, only database resources are active.

In the filters panel, you can check or uncheck a resource to display or not display the performance metrics for that resource.

In order to focus on the resources of interest, you can collapse a category by clicking on the triangle in the right-hand section of the panel. The number of resources for the collapsed category are displayed.

Clicking the checkmark updates the charts with the current filter settings. It does not apply any changes that may have been made to the above TIME SPAN settings.

You can mouse over the resource names in the filter list to get extra information about the resources. For example, mousing over a host name shows the number of forests associated with the host and mousing over a server name shows the server type.

Historical Performance Charts by Resource

From the Monitoring History dashboard, you can view Overview and Detailed performance metrics in graph form for each resource in the cluster. In the Overview page, the lines on a graph represent an aggregate of the metrics for all of the cluster resources of that type. In each Details page, the lines represent the metric for each specific resource in the cluster.

To view the Detail page for a resource, click on the down arrow at the upper left-hand section of the resource graph on the Overview page.

To return to the Overview page from a Detail page, click on the up arrow at the upper left-hand section of the resource graph on the Detail page.

This section describes the Overview and Detail pages for the following resources:

• Disk Performance Data
• CPU Performance Data
• Memory Performance Data
• Server Performance Data
• Network Performance Data
• Database Performance Data

Exporting and Printing Monitoring History

You can export and print your Monitoring History data.

To export the Monitoring History data to an Excel Spreadsheet file, click the Export at the upper-right portion of the Monitoring History page.

The metrics are displayed in separate tabs at the bottom of the spreadsheet.

To print out the charts displayed on the current page, click Print. This will open the printer dialog page from which you can print the charts.