Disk spooler - AWS IoT Greengrass

Disk spooler

The disk spooler component (aws.greengrass.DiskSpooler) offers a persistent storage option for messages spooled from Greengrass core devices to AWS IoT Core. This component will store these outbound messages on disk.

Versions

This component has the following versions:

  • 1.0.x

Type

This component is a plugin component (aws.greengrass.plugin). The Greengrass nucleus runs this component in the same Java Virtual Machine (JVM) as the nucleus. The nucleus restarts when you change this component's version on the core device.

This component uses the same log file as the Greengrass nucleus. For more information, see Monitor AWS IoT Greengrass logs.

For more information, see Component types.

Operating system

This component can be installed on core devices that run the following operating systems:

  • Linux

  • Windows

Requirements

This component has the following requirements:

  • storageType should be set to Disk to use this component. You can set this in the Greengrass nucleus configuration.

  • maxSizeInBytes must not be configured to be greater than the available space on the device. You can set this in the Greengrass nucleus configuration.

  • The disk spooler component is supported to run in a VPC.

Dependencies

When you deploy a component, AWS IoT Greengrass also deploys compatible versions of its dependencies. This means that you must meet the requirements for the component and all of its dependencies to successfully deploy the component. This section lists the dependencies for the released versions of this component and the semantic version constraints that define the component versions for each dependency. You can also view the dependencies for each version of the component in the AWS IoT Greengrass console. On the component details page, look for the Dependencies list.

1.0.1 – 1.0.3

The following table lists the dependencies for versions 1.0.1 to 1.0.3 of this component.

Dependency Compatible versions Dependency type
Greengrass nucleus >=2.11.0 <2.13.0 Hard
1.0.0

The following table lists the dependencies for version 1.0.0 of this component.

Dependency Compatible versions Dependency type
Greengrass nucleus >=2.11.0 <2.12.0 Hard

For more information about component dependencies, see the component recipe reference.

Usage

To use the disk spooler component, aws.greengrass.DiskSpooler must be deployed.

To configure and use this component, you must set the pluginName to aws.greengrass.DiskSpooler.

Local log file

This component uses the same log file as the Greengrass nucleus component.

Linux
/greengrass/v2/logs/greengrass.log
Windows
C:\greengrass\v2\logs\greengrass.log
To view this component's logs
  • Run the following command on the core device to view this component's log file in real time. Replace /greengrass/v2 or C:\greengrass\v2 with the path to the AWS IoT Greengrass root folder.

    Linux
    sudo tail -f /greengrass/v2/logs/greengrass.log
    Windows (PowerShell)
    Get-Content C:\greengrass\v2\logs\greengrass.log -Tail 10 -Wait

Changelog

The following table describes the changes in each version of the component.

Version

Changes

1.0.3

Bug fixes and improvements

Improves performance by reusing database connections.

1.0.2

Bug fixes and improvements

Fixes an issue where the MQTT message format field isn't persisted in certain cases.

1.0.1

Version updated for Greengrass nucleus version 2.12.0 release.

1.0.0

Initial version.