v4.0 Architecture

Basic Terms

• Storage

  A storage which performance is been measured in the test. Currently several types of storages are supported.

• Item

  The unit to account the performance rates. Maybe a file, object, directory, bucket, etc. An Item has the identifier property (name).

• Data Item

  An Item with a data payload. Any Data Item has the corresponding size property.

• Item Input

  The readable source of the items. This may be a CSV file, a binary stream, a collection or a bucket listing.

• Item Output

  The writable destination for the items. This may be a CSV file, a binary stream or a collection.

• I/O Task

  An I/O task is a item linked with a particular I/O type (write/read/delete). Also, any I/O Task has the state and the execution result as an extension of this state.

• Load Step

  Load step is an unit of metrics reporting and test execution flow.

  For each load step:

  • total metrics are calculated and reported
  • limits are configured and controlled

• Scenario

  A set of load steps combined and organized using flow elements provided by a scripting engine which supports JSR-223. Mongoose invokes the default scenario if no custom scenario is specified. The default scenario just runs the single linear load step.

Components

Storage Driver

Executes the I/O tasks generated by Load Generators. The basic property is the concurrency level and storage client configuration. The functionality includes:

• Low-level implementation of the I/O tasks execution functionality
• Rate limit related things
• Callbacks for the completed I/O Tasks

Load Generator

Load Generator is a component which generates the I/O tasks from the items got from the input. Many storage drivers may be associated with a load generator. The basic properties are:

• Origin Index (all I/O tasks generated share the same origin index)
• I/O type (create/read/etc)
• Shared rate throttle
• Shared weight throttle
• Storage drivers list
• Storage drivers balancer

Load Controller

A load controller is an unit of test step control. Functionality:

• Configuration deployment
• Test initiation
• Execution control (timeouts handling, shutdown invocations, etc)

Metrics Manager

Metrics aggregation and representation. The component is a singleton which was differentiated from the Load Controller component. Many load controllers may be associated with the single metrics manager.