Accounting

Overview

GCube Accounting allows to collect information of the infrastructure usage and expose them for the interested consumer.

Key Features

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description

Design

Architecture

The following picture shows the gCube Accounting architeture

The Accounting Architecture has been logically divided in three different layers.

• Accounting Consumer Layer
• Accounting Enabling layer
• Accounting Backend layer

Moreover we have the storage layer which is not a gCube component in terms of development.

• Accounting Storage layer

All the developed component must respect this architecture. In particular, the design and the implementation has to respect the following rules:

• Each enabling layer has its own correspondent backend implementation.
• Each backend implementation must be dynamically discovered at runtime. This allow to decouple the deployment of a different backend from the development of the enabling layer. In other word each component on the enabling layer MUST NOT have any dependency over a certain backed implementation.

The only entitled software to depend to the backend component are:

• bundles (e.g. smartgear-bundle, portal-bundle)
• provisioning script

Accounting Enabling Layer

• Accounting Lib is responsible of collecting, harmonizing and storing Accounting data. Accounting Lib is mainly based and developed on top of facilities provided by Document Store Lib
• Accounting Analytics is responsible of exposing a common access point interface to query the collected Accounting data.
• Accounting Aggregator is responsible of aggregating the collected Accounting data.

Accounting Storage Layer

This layer is not developed by gCube but the selected technology has to be selected to provide HA (High Availability). Actually CouchDB has been selected as storage for accounting data. MongoDB, OrientDB and CouchBase have been investigated. CouchBase has been selected as next storage for accounting Data.

Accounting Backend Layer

• document-store-lib-BACKEND (implementations available: document-store-lib-couchdb, document-store-lib-couchbase, document-store-lib-mongodb)
• accounting-analytics-persistence-BACKEND (implementations available: accounting-analytics-persistence-couchdb, accounting-analytics-persistence-couchbase is under development see [1])
• accounting-aggregator-persistence-BACKEND (e.g. accounting-aggregator-persistence-couchdb)

Each component in this layer has been explicitly developed over a certain storage technology. Each component MUST NOT rely on IS to discover the information needed to connect to the underling storage. In other words the component MUST NOT have an hard-cabled connection information or a local configuration files. To retrieve the storage connection information the following parameter must be part of the query:

• underlying storage technology
• enabling component

The first constraint allow to switch to different storage avoiding to switch all nodes together (two underling storage can co-exist). The second allow to keep separated the connection information for each component. This allow to provide create different access policy for different component (e.g. write only for accounting-lib connection and read only for accounting-analytics).

Accounting Consumer Layer

In this layer we found not only the accounting consumer which retrieve information related to collected data (e.g. Accounting Portlet) but also all the component which collect data and use accounting-lib to persist in a common pattern.