DataBot User Manual

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os-stats

Overview

os-stats is a low-overhead O/S level event collector that generates events-compatible events. os-sats is designed to run as a system daemon, indefinitely. Only one os-stats instance per VM is necessary. os-stats will collect timed events and channel them to various destinations, such as files, network, etc. It is capable of collecting memory, CPU, etc. usage statistics, as well as WildFly management domain model and JMX metrics.

Installation

Download the stable release from

https://github.com/NovaOrdis/os-stats/releases

The release consists in a ZIP file with a name matching "os-stats-<version>.zip".

Unzip the release file in a conventional binary directory, such as /opt or /usr/local. An "os-stats-<version>" sub-directory will be created.

Add .../os-stats-<version>/bin to PATH.

os-stats needs a Java VM to run. It will attempt to use, in this order:

1. Value of "OS_STATS_JAVA_HOME" environment variable, if set.
2. Value of "JAVA_HOME" environment variable, if set.
3. The "java" executable found in path.

Configuration File

Choose a directory to store the configuration file. If the configuration will be shared by multiple users and there will be used by just one os-stats instance on the system, we recommend /etc/os-stats. Otherwise, each user could maintain an individual configuration file in ~/.os-stats (recommended) or a directory of their choosing. The location of the configuration file should be exposed as the value of the OS_STATS_CONF environment variable in the environment of the user who will execute os-stats. If no OS_STATS_CONF environment variable is defined, os-stats will attempt to read ~/.os-stats/os-stats.yaml.

The configuration file location can be overridden from command line using -c|--configuration= options. If one of these options is specified, the environment variables and default locations are ignored.

Regardless of how the configuration file is declared, os-stats will fail if the file is not found. For details on the configuration file syntax see Configuration section below.

Complete any of target-specific configuration procedures, if they apply.

Usage

If an os-stats process is already running in the background, an attempt to start another os-stats instance will fail.

To start an instance that runs in foreground, use --foreground command line option. In foreground mode, the output is switched automatically from the configured file destination to /dev/stdout and the output.file configuration, as described below, is ignored.

Commands

help

Display in-line help.

version

Display version information.

status

Display whether a background os-stats process already runs on the system. If a process is found running, the command provides more information about it (such as the PID).

stop

Stop the background os-stats process, if running.

Options

-fg|--foreground

Run the command in foreground and automatically switch the output from the configured file destination to /dev/stdout.

-v|--verbose

Turns on DEBUG logging at stdout.

-d|--debug

Start the JVM in debug mode, so it can be accessed by a debugger. It also turns on DEBUG logging.

Configuration:

sampling.interval - the sampling interval, in seconds. If not specified, the default is 10 seconds.

output.file - the name of the output file. If not specified, the default value is

   /tmp/os-stats.csv. Note that if --foreground (or -fg) option is used, the output will forcibly
   send to /dev/stdout, regardless of the value of 'output.file' configuration parameter.

output.file.append - true/false. Indicates whether to append to an already existing output file or

   to overwrite the existing file. The default value is "true" (append);  this configuration will
   allow accumulation of  historical data.  Every time os-stats is restarted in "append" mode,  a
   new header line will be inserted in the file.

metrics - comma-separated list of the definitions for the metrics to be collected from the system.

   Example:

   metrics=PhysicalMemoryUsed,CpuUserTime,jboss:/subsystem=web/connector=http/bytesReceived

   For  a complete list  of supported metrics,  syntax details  and extensive documentation,  see
   https://kb.novaordis.com/index.php/Os-stats_Metric_Reference

jboss.home - the path to a locally accessible JBoss instance. If it needs to monitor JBoss CLI

   metrics,  os-stats must be configured to detect and use the libraries from a JBoss instance it
   has access to (it does not ship with the required JARs, as those may be different depending on
   the version of the target JBoss instance.  In order to enable os-stats  to build the classpath
   fragment, jboss_home must be specified in the configuration file.

In-Line Help

os-stats --help

Configuration

Example

#
# os-stats configuration file
#

#
# sampling interval (in seconds)
#
sampling.interval: 20

#
# output configuration
#
output:
  file: /home/vagrant/tmp/os-stats.csv
  append: true

#
# metrics
#
metrics:
  - PhysicalMemoryTotal

Metric Reference

Metric Reference