Statistics

This page describes the statistics available in the Weka system and how to work with them.

Overview

As the Weka system runs, it collects hundreds of statistics on system performance. These statistics help in analyzing the Weka system performance and determining the source of any problems.

Five different categories of statistics are available for review - Operations (NFS), Operations (Driver), Object Store, SSD and CPU – and when each category is selected, a list of the possible statistics that can be selected is displayed.

By default, the main statistics page displays the last hour of operation, presenting the Weka system operation per second on a time axis.

This Statistics view screen offers a number of options to drill-down into the statistics, according to category. Options include:

Mousing over the scrollable graph area to view various performance metrics of the Weka cluster.
Troubleshooting or obtaining a correlation between events and performance (using the top line which provides links to events that occurred).
Adding more statistics to the view (using the Statistics menu).
Displaying different statistics simultaneously and toggling between them. By default, the graph area shows Ops/sec for the last hour. Using the "Hour, Day, Week" buttons
at the bottom-right enables changing of the time interval.
Displaying, hiding. deleting, and zooming-in on statistics from defined timelines and dates.
Bookmarking specific statistics for future reference and sharing with others (using the URL).

Note: The statistics are only shown for backend/clients that are part of the cluster. Once a host is removed (or a client is not connected to the cluster for more than the remove_after_secs period) its statistics will not be shown. The Weka cluster does not hold historical statistics data. Use weka-mon for that, as suggested in the External Monitoring section.

Working with Statistics Using the GUI

Viewing Statistics

To view the statistics screen using the GUI, click the statistics button on the left bar:

Adding Statistics

To select the addition of specific statistics, click the + Add Statistics tab on the right-hand side of the Statistics view screen. The statistics menu will be displayed.

Then select the component for which statistics required from the six possible categories. As each component is selected, the list of possible Statistics Names that can be selected changes. It is also possible to searching for a specific statistic by typing the name of the statistic in the Filter field at the top of the menu.

Up to 5 different statistics can be displayed simultaneously. Selecting a metric adds its graph to the Statistics view, together with a selector containing the category and name of the statistics which are displayed according to the appropriate units.

Switching the active unit scale is performed by clicking on one of the inactive units displayed in the left bottom corner of the graph display box.

Hiding/Deleting Statistics

To hide or delete statistics from a graph, mouse-over the selector and click either the Hide or Delete button appearing under the selector.

Specifying a Time Frame

To define a specific period of time (start and end) for the statistics to be displayed, click the From and To selectors appearing in the left corner of the graph display box. Then select the date of the statistics required from the calendar popup and the hours from the right scroller, or by using the up and down arrows that appear when hovering on the time selectors.

Note: It is also possible to change the time period by dragging the graph left or right.

The Auto Refresh setting offers another option for defining a specific period of time. Activation of Auto Refresh is performed by clicking on one of the buttons displayed in the right bottom corner of the graph display box, according to the desired period (hour, day or week). The selected period of time for the statistics will be automatically updated every minute, until Auto Refresh is deactivated by clicking the 'x' button located at the top right of the Auto Refresh tool tip, or by defining a period of time using the time selector.

Obtaining a Summary of Events

To obtain a summary of events that occurred in a specific time period, click the events bubble displayed above the graph. The Events popup will be displayed. Expand the popup in order to obtain a detailed list of events. Click on the icon next to each event to link to the selected event in the Events view screen.

Working with Statistics Using the CLI

Listing Statistics Types

Command: weka stats list-types

Use the following command line to obtain statistics definition information: weka stats list-types [<name-or-category>] [--show-internal]

Parameters in Command Lines

Name

Type

Value

Limitations

Mandatory

Default

name-or-category

String

Name or category fo filter by

Valid name or category

show-internal

Boolean

Also displays internal statistics

False

Viewing Statistics

Command: weka stats realtime

Use the following command line to obtain the current performance-related statistics of the hosts, in a one-second interval: weka stats realtime [<node-ids>] [--raw-units] [--UTC]

Parameters in Command Lines

Name

Type

Value

Limitations

Mandatory

Default

node-ids

Comma-separated strings

Only show realtime stats of these nodes

raw-units

Boolean

Print values in raw units (bytes, seconds, etc.)

Human-readable format, e.g 1KiB 234MiB 2GiB

UTC

Boolean

Print times in UTC

Host's local time

Command: weka stats

The collected statistics are helpful to analyze system performance and determine the source of any problems as the Weka system runs, according to several categories. When each category is selected, a list of the possible statistics that can be selected is displayed.

Note: All statistics are averaged over one-second intervals. Consequently, "total" or other aggregates relate to a specific minute.

Use the following command line to manage filters and read statistics:

weka stats [--start-time <start-time>] [--end-time <end-time>] [--interval interval] [--resolution-secs resolution-secs] [--category category][--stat stat] [--node-ids node-ids] [--param param] [--accumulated] [--per-node] [--no-zeros] [--show-internal] [--raw-units] [--UTC]

Parameters in Command Lines

Name

Type

Value

Limitations

Mandatory

Default

start-time

String

Start time of the reported period

Format: 5m, -5m, -1d, -1w, 1:00, 01:00, 18:30, 18:30:07, 2018-12-31 10:00, 2018/12/31 10:00, 2018-12-31T10:00, 9:15Z, 10:00+2:00

-1m

end-time

String

End time of the reported period

Format: 5m, -5m, -1d, -1w, 1:00, 01:00, 18:30, 18:30:07, 2018-12-31 10:00, 2018/12/31 10:00, 2018-12-31T10:00, 9:15Z, 10:00+2:00

Current time

interval

String

Period of time to be reported

Valid interval in seconds (positive integer number)

Yes

resolution-secs

String

Length of each interval in the reported period

Must be multiples of 60 seconds

category

String

Specific categories for retrieval of appropriate statistics

Valid existing categories: CPU, Object Store, Operations, Operations (NFS), Operations (Driver), SSD

All

stat

String

Statistics names

Valid statistics names

All

node-ids

String

Node id

Valid node-id

All

param

String

For parameterized statistics, retrieve only the instantiations where the specified parameter is of the specified value. Multiple values can be supplied for the same key, e.g. '--param method:putBlocks --param method:initBlock'

Format: key:val

accumulated

Boolean

Display accumulated statistics, not rate statistics

False

per-node

Boolean

Does not aggregate statistics across nodes

False

no-zeros

Boolean

Filters results where the value is 0