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Agent Start-up

Start Script: agent.sh, agent.cmd

The JS7 Agent includes a Start Script for managing the Agent:

  • The default location of the Start Script is:
    • /opt/sos-berlin.com/js7/agent/bin/agent.sh on Unix and

    • C:\Program Files\sos-berlin.com\js7\agent\bin\agent.cmd on Windows.

Usage

Running the Agent Start Script without arguments displays the usage clause:

Usage for Unix
Usage: agent.sh command [options]
  command:
    start         [options]
    start_docker  [options]
    stop          [options]
    abort         [options]
    restart       [options]
    status        [options]
    kill          [options]
    cert          [cert-options]                      | see https://kb.sos-berlin.com/x/jLbAAw
  options:
    --http-port=<[hostname or ip address:]number>     | default: 4445
    --https-port=<[hostname or ip address:]number>    | default:
    --data-directory=<location of data directory>     | default: /var/sos-berlin.com/js7/agent/var_4445
    --config-directory=<location of config directory> | default: /var/sos-berlin.com/js7/agent/var_4445/config
    --sigkill                                         | only for stop and restart; running tasks will be killed
    --timeout=<timeout > 0, in seconds>               | only for stop; if timeout is reached then SIGKILL is sent
    --kill-script=<location of kill script>           | only for start
    --java-options=<java options>                     | default:  -Xms100m -Dlog4j2.contextSelector=org.apache.logging.log4j.core.async.AsyncLoggerContextSelector -Dlog4j2.asyncLoggerWaitStrategy=Block; see https://kb.sos-berlin.com/x/aIC9
see https://kb.sos-berlin.com/x/fAmGAw for more information.



Usage for Windows
Usage: agent.cmd command [options]
  command:
    start         [options]
    start_docker  [options]
    stop          [options]
    abort         [options]
    restart       [options]
    status        [options]
    kill          [options]
    cert          [cert-options]                      | see https://kb.sos-berlin.com/x/jLbAAw
  options:
    --http-port=<[hostname or ip address:]number>     | default: 4445
    --https-port=<[hostname or ip address:]number>    | default:
    --data-directory=<location of data directory>     | default: /var/sos-berlin.com/js7/agent/var_4445
    --config-directory=<location of config directory> | default: /var/sos-berlin.com/js7/agent/var_4445/config
    --sigkill                                         | only for stop and restart; running tasks will be killed
    --timeout=<timeout > 0, in seconds>               | only for stop; if timeout is reached then KILL is sent
    --kill-script=<location of kill script>           | only for start
    --java-options=<java options>                     | default:  -Xms100m -Dlog4j2.contextSelector=org.apache.logging.log4j.core.async.AsyncLoggerContextSelector -Dlog4j2.asyncLoggerWaitStrategy=Block; see https://kb.sos-berlin.com/x/aIC9
see https://kb.sos-berlin.com/x/fAmGAw for more information.

Command Line Options

  • --http-port=<[hostname or ip address:]number>
    • Specifies the HTTP port that the Agent is listening to in order to receive requests from a JS7 Controller:
      • agent.sh|.cmd --http-port=####

      • where #### is the port number.
      • This option can be used to indicate which network interface the JS7 Agent should listen to if a hostname or IP address is specified, for example with --http-port=myhost:4445.
    • Without this option being used the port defaults to 4445 and the Agent listens to all available network interfaces.
    • If a port is specified then the following order of precedence applies:
      • First precedence: command line option
      • Second precedence: environment variable JS7_AGENT_HTTP_PORT (see below)
      • Third precedence: use of default value
  • --https-port=<[hostname or ip address:]number>
    • Specifies the HTTPS port that the Agent is listening to in order to receive requests from a Controller:
      • agent.sh|.cmd command --https-port=####

      • where #### is the port number.
      • This option can be used to indicate which network interfaces the Agent should listen to if a hostname or IP address is specified, for example, with --https-port=myhost:4445.
    • When using the HTTPS protocol for connections from a Controller instance consider additionally allowing the HTTP protocol for local connections as with --http-port=localhost:4445. As the Agent Start Script makes use of an HTTP connection this protocol has to be in place to allow the Agent to be started, stopped, etc. by its Start Script.
    • Without this option being used the port defaults to 4445 and the Agent listens to all available network interfaces.
    • If a port is specified then the following order of precedence applies:
      • First precedence: command line option
      • Second precedence: environment variable SJS7_AGENT_HTTPS_PORT (see below)
      • Third precedence: use of default value
  • --data-directory=<location of data directory>
    • Specifies the location of the data directory that usually includes the config, logs, tmp and state directories.
    • This location has to be unique for any Agent instance.
    • If a data directory is specified then the following order of precedence applies:
      • First precedence: command line option
      • Second precedence: environment variable JS7_AGENT_DATA (see below)
      • Third precedence: use of default value JS7_AGENT_HOME/var_<JS7_AGENT_PORT>
  • --config-directory=<location of config directory>
    • Specifies the location of the config directory for configuration data.
    • This location has to be unique for any Agent instance.
    • Should a configuration directory be specified then the following order of precedence applies:
      • First precedence: command line option
      • Second precedence: environment variable JS7_AGENT_CONFIG_DIR (see below)
      • Third precedence: use of default value JS7_AGENT_HOME/var_<JS7_AGENT_PORT>
  • --sigkill
    • With the stop and restart commands this option kills any running processes of jobs by use of a SIGKILL signal.

  • --timeout
    • With the stop command this option waits for the indicated number of seconds and kills the Agent including any running processes of jobs if the timeout is exceeded.

  • --kill-script=<location of kill script>
    • The kill script provides the functionality to kill tasks and any child processes of jobs.

    • Kill scripts are by default provided from the following locations:
      • JS7_AGENT_DATA/work/kill_task.sh for Unix.

      • JS7_AGENT_DATA\work\kill_task.cmd for Windows.

    • This option can be used to specify the location of an individual kill script if required.

    • Should an individual kill script be specified then the following order of precedence applies:

      • First precedence: command line option
      • Second precedence: environment variable JS7_AGENT_KILL_SCRIPT (see below)
      • Third precedence: use of default value
  • --java-options=<java options>
    • This option can be used to apply Java options for the Agent, e.g. for memory settings.

    • Without this option being used the Java options default to -Xms100m.

    • In order to specify a number of Java options quotes have to be used like this:
      • --java-options="-Xms100m -Xmx1g"
    • When specifying Java options then the following order of precedence applies:

      • First precedence: command line option
      • Second precedence: environment variable JAVA_OPTIONS (see below)
      • Third precedence: use of default value
  • --job-java-options=<java options>
    • This option can be used to specify Java options for Shell jobs that load a JVM. This option does not apply to jobs derived from JS7 - Job Templates that are executed in the Agent's JVM.
    • In order to specify a number of Java options quotes have to be used like this:
      • --job-java-options="-Xms100m -Xmx1g"
    • When specifying Java options for execution with Shell jobs then the following order of precedence applies:

      • First precedence: command line option
      • Second precedence: environment variable JS7_AGENT_JOB_JAVA_OPTIONS (see below)

Instance Start Script: agent_<port>.sh, agent_<port>.cmd

The JS7 Agent includes a template file for an Instance Start Script that can be adjusted to specify start-up parameters.

  • The Instance Start Script sets a number of environment variables and finally executes the Start Script.
  • In the Instance Start Script start-up parameters can be specified from environment variables, see below.

It is recommended that an individual Instance Start Script is created from the template file as this allows individual start-up parameters to specified using environment variables.

Location

  • The default location of the Instance Start Script template file is:
    • /opt/sos-berlin.com/js7/agent/bin/agent_instance.sh-example on Unix systems and

    • C:\Program Files\sos-berlin.com\js7\agent\bin\agent_instance.cmd-example on Windows.
  • Users can create a copy of the template file and remove the -example extension from the file name. The renamed Instance Start Script will not be overwritten when updating the Agent later on.
  • It is recommended that the template file is copied to an Instance Start Script file with the name agent_<port>.sh|.cmd with <port> being the HTTP port used by the Agent (see below).
    • If the Agent installation is performed on Windows using the installer, either in headless mode or in graphical mode, then the installer will automatically create this script.
    • If the Agent installation is performed by extracting a .tar.gz/.zip archive then the Instance Start Script has to be created from a copy of the template file.
    • Users can adjust start-up parameters from environment variables once the Instance Start Script has been copied, as described below.

Usage

The Instance Start Script can be executed with the same arguments as the Start Script, as described above.

Agent Environment Variables

Most environment variables in the Instance Start Script correspond to command line options in the Start Script (described above). The following environment variables can be modified in the script:

  • JS7_AGENT_HOME
    • Points to the directory where the JS7 Agent has been installed.
    • If this environment variable is not set then the default value will be used, which is the parent directory of the Agent Start Script.
    • If the Agent is started from a directory other than the Agent installation directory, for example by copying the Start Script to some other location, then this environment variable has to be set in order to locate the JS7 Agent installation directory.
    • There is no corresponding command line option.
  • JS7_AGENT_USER
    • Sets the user account that the Agent is operated for. This includes running jobs with the permissions of the specified user account.
    • This setting is available for Unix systems only. For Windows systems the user account that runs the Windows Service is used.
    • Without setting this environment variable the user account that runs the Start Script is used.
    • This setting can be used when running the Agent Start Script on system start-up and shutdown that are executed by root, for example in /etc/init.d and corresponding locations or with systemd.
    • There is no corresponding command line option.
  • JS7_AGENT_HTTP_PORT
    • Sets the HTTP port that the Agent is listening to.
    • Indicates which network interfaces the Agent should listen to if a hostname or IP address is specified, for example with JS7_AGENT_HTTP_PORT=myHost:4444.
    • If only a port number is specified then the Agent will listen to all available network interfaces via HTTP.
    • Without setting this environment variable the default port of 4445 will be used.
    • Corresponding command line option: --http-port
  • JS7_AGENT_HTTPS_PORT
    • Sets the HTTPS port that the Agent is listening to.
    • Indicates which network interfaces the Agent should listen to if a hostname or IP address is specified, for example with JS7_AGENT_HTTPS_PORT=myHost:4443.
    • If a port number only is specified then the Agent listens to all available network interfaces via HTTPS.
    • When using the HTTPS protocol for connections from a Controller users should consider to allow the HTTP protocol for local connections as with JS7_AGENT_HTTP_PORT=localhost:4445. As the Agent Start Script makes use of an HTTP connection, this protocol has to be in place to allow the Agent instance to be started, stopped etc. by its Start Script.
    • Without setting this environment variable the HTTPS protocol is not used.
    • Corresponding command line option: --https-port
  • JS7_AGENT_DATA
    • Points to the location where the Agent finds its configuration data, log data and journals.
    • Without setting this environment variable the default value is JS7_AGENT_HOME/var_<JS7_AGENT_HTTP_PORT>.
    • Corresponding command line option: --data-directory
  • JS7_AGENT_CONFIG_DIR
    • Points to the directory where the Agent finds its configuration data.
    • Without setting this environment variable the default value is JS7_AGENT_DATA/config.
    • Corresponding command line option: --config-directory
  • JS7_AGENT_LOG_DIR
    • Specifies the directory where the Agent log files are created.
    • This setting defaults to the sub-directory logs in the JS7_AGENT_DATA directory.
    • There is no corresponding command line option.
  • JS7_AGENT_PID_FILE_DIR
    • Specifies the directory where the Agent PID file is created.
    • This setting defaults to the directory that is specified with the JS7_AGENT_LOG_DIR environment variable or the log directory default value.
    • There is no corresponding command line option.
  • JS7_AGENT_PID_FILE_NAME
    • Sets the file name to which the JS7 Agent stores its PID.
    • The default value is agent.pid.
    • There is no corresponding command line option.
    • FEATURE AVAILABILITY STARTING FROM RELEASE 2.5.1
  • JS7_AGENT_WORK_DIR
    • Specifies the working directory for the jobs started by the Agent, e.g. ${HOME} or %USERPROFILE%.
    • This setting defaults to JS7_AGENT_DATA.
    • There is no corresponding command line option.
  • JS7_AGENT_KILL_SCRIPT
    • Specifies the location of a kill script if an individual script is required.
    • The kill script allows the task and any child processes of a job to be killed.

    • Kill scripts are by default provided at the following locations:
      • JS7_AGENT_DATA/tmp/kill_task.sh for Unix.

      • JS7_AGENT_DATA\tmp\kill_task.cmd for Windows.

    • Corresponding command line option: --kill-script
  • JAVA_HOME
    • Points to the location of the JVM, either a JRE (Java Runtime Environment) or JDK (Java Development Kit).
    • When this environment variable is not set, Java will be used from the location specified by the system path.
    • The JAVA_HOME environment variable does not necessarily point to the location of a JDK but to a JRE directory where the bin/java executable resides. For example, if the location of the Java executable is /opt/java/jdk8u202-b08/jre/bin/java then JAVA_HOME=/opt/java/jdk8u202-b08/jre.
    • There is no corresponding command line option.
  • JAVA_OPTIONS
    • Sets Java options, e.g. the Java memory settings for the Agent.
    • When this environment variable is not set, the Java options will default to -Xms100m.
    • Corresponding command line option: --java-options
  • JS7_AGENT_JOB_JAVA_OPTIONS
    • Sets Java options for shell jobs that start a JVM.
    • Corresponding command line option: --job-java-options

Individual Environment Variables

In addition to Agent Environment Variables individual environment variables can be added. Such environment variables are made available for jobs like this:

Usage on Unix
SCRIPT_PATH=/var/scripts
export SCRIPT_PATH
Usage on Windows
set SCRIPT_PATH=C:\ProgramData\scripts

Running the Agent

  • SOS does not recommend running the JS7 Agent with the root account (for Unix) or the Administrator account (for Windows).
    • In fact the Agent can be operated with administrative privileges which leverages switching to any user account without specifying a password if jobs are to be executed for a different user account.
    • However, in compliance-aware environments this is considered an unwanted risk and in any other environments this simply is a bad idea.
  • For Unix use of sudo is recommended.
  • For Windows the JS7 Agent can switch to a different user account in a compliant way, see JS7 - Running Jobs as a different User.

The examples listed below make use of an Instance Start Script agent_4445.sh|.cmd, which is created from the template file to run the Agent using port 4445.

Starting the Agent

agent_4445.sh|.cmd start [options]

Stopping the Agent

agent_4445.sh|.cmd stop [options]

This command will safely terminate the Agent (recommended).

  • The Agent waits for running processes of any jobs to be completed.
  • Using the --sigkill command line option will terminate the Agent normally and will kill any running processes.
  • Using the --timeout command line option will terminate the Agent and will kill any running processes when the number of seconds specified for the timeout is exceeded.


agent_4445.sh|.cmd abort [options]

The Agent process is immediately aborted.

  • Any running tasks and child processes of jobs are killed immediately with a SIGKILL signal.
  • Should tasks use resources such as database connections then they will not be properly closed.


agent_4445.sh|.cmd kill [options]

The Agent process is killed.

  • This corresponds to sending a SIGKILL signal with a kill -9  command (Unix) or taskkill command (Windows).
  • Should jobs be running that start detached child processes then it is not guaranteed that child processes will be killed.

Restarting the Agent

agent_4445.sh|.cmd restart [options]

This command will safely restart the Agent (recommended).

  • The Agent waits for running processes of any jobs to be completed.
  • Using the --sigkill command line option will terminate the Agent normally, kill any running processes and restart the Agent.

Checking the Agent Status

agent_4445.sh|.cmd status [options]


If the Agent is up and running then this command results in output such as:

version: 2.0.0-alpha.20210722.2 (2021-07-22)
buildId: QQqWYNiJRbqcYqx4iiFWww
startedAt: 1626981330629
isTerminating: false
system:
  hostname: agent-2-0-primary
  distribution: Alpine Linux v3.13
  cpuModel: Intel(R) Xeon(R) CPU E5-2630 v4 @ 2.20GHz
  mxBeans:
    operatingSystem:
      availableProcessors: 8
      systemLoadAverage: 0.0107421875
java:
  version: 1.8.0_292
  memory:
    maximum: 954728448
    total: 289931264
    free: 87118936
  systemProperties:
    java.vendor: IcedTea
    os.arch: amd64
    java.runtime.name: OpenJDK Runtime Environment
    os.version: 3.10.0-957.1.3.el7.x86_64
    os.name: Linux
    java.vm.name: OpenJDK 64-Bit Server VM
    java.version: 1.8.0_292

Performing Certificate Rollout

agent_4445.sh|.cmd cert [cert-options]

This command is used to generate an SSL certificate for client and server authentication. 

For details and command line options see JS7 - Certificate Authority - Rollout Certificates for HTTPS Connections

Windows Service Interface

The following information applies to headless installation for Windows systems. For installation with a GUI and user dialog see JS7 - Agent - Installation Using the Windows Graphical Installer.

The Agent is operable as a Windows Service. The Start Script of the Agent allows the installation/removal of the Windows Service.

The examples below make use of an Instance Start Script agent_4445.cmd, which is created from the template file to run the Agent for port 4445.

Installing the Windows Service

agent_4445.cmd install-service [--http-port=<number>]

This command installs the Agent's Windows Service. After the installation, users find the Windows Service with the name SOS JS7 Agent -port=<number> in the Services Manager Console. The Windows service uses the local system account.

During service installation, the installer tries to copy the executable file for the Windows Service to the .\service directory. This operation could fail with the error "Access denied" if the Agent has been extracted to, for example, C:\Program Files. In this case users can change the permissions of the .\service directory or open the command prompt with elevated administrator rights and execute the above command once again.

Starting the Windows Service

agent_4445.cmd start-service [--http-port=<number>]

This command starts the Windows Service with the name SOS JS7 Agent -port=<number>.

The stop command performs more than a simple stop-service command: the stop command checks whether the Agent was started by the command line interface or as a Windows Service and stops the Agent accordingly. Therefore there is no stop-service command.

Removing the Windows Service

agent_4445.cmd remove-service [--http-port=<number>]

This command removes the Windows Service. After executing this command users should not find the Windows Service with the name SOS JS7 Agent -port=<number> in the Services Manager Console any longer.

During removal of the service the Agent Start Script tries to remove the executable file of the Windows Service from the .\service directory. This operation could fail with the error "Access denied" if users have extracted the Agent to e.g. C:\Program Files. In this case users can change the permissions of the .\service directory or open the command prompt with elevated administrator rights and execute the above command once more.

Configuring the Windows Service

After installation of the Windows Service users find the .\service\js7_agent_<http-port>w.exe file. This program can be executed to configure the Windows Service.

For example go to the "Startup" tab
to modify start parameters

Debugging the Windows Service

  • The Agent log level can be increased by using the Agent's Apache ProcRun Daemon Service Manager daemon/service.
  • On Windows systems this is installed in the Agent's service folder with a name such as js7_agent_<port>w.exe  where <port> is the Agent's HTTP port.
  • Users can start the ProcRun Manager, select the Logging tab in the user interface and set the log level to Debug
  • The location of log files is explained above. 
  • Users should consider reverting the debug log level to its original value once they are finished with debugging.