Extended accounting (exacct) is an accounting framework for the Oracle Solaris operating system that provides additional functionality to that provided by the traditional SVR4 accounting mechanism. Traditional SVR4 accounting has these drawbacks:
The data collected by traditional accounting cannot be modified.
The type or quantity of statistics SVR4 accounting gathers cannot be customized for each application. Changes to the data that traditional accounting collects would not work with all of the existing applications that use the accounting files.
The SVR4 accounting mechanism is not open.
Applications cannot embed their own data in the system accounting data stream.
The traditional accounting mechanism has no aggregation facilities.
The Oracle Solaris operating system writes an individual record for each process that exists. No facilities are provided for grouping sets of accounting records into higher-level aggregates.
The exacct framework addresses the limitations of traditional accounting and provides a configurable, open, and extensible framework for the collection of accounting data.
The data that is collected can be configured using the exacct API.
Applications can either embed their own data inside the system accounting files, or create and manipulate their own custom accounting files.
The lack of data aggregation facilities in the traditional accounting mechanism are addressed by tasks and projects. Tasks identify a set of processes that are to be considered as a unit of work. Projects allow the processes executed by a set of users to be aggregated into a higher-level entity. See the project(4) man page for more details about tasks and projects.
For a more extensive overview of extended accounting, see Chapter 4, About Extended Accounting in Administering Resource Management in Oracle Solaris 11.3.