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Chapter 4
Extended Accounting (Overview)
By using the project and task facilities that are described in Chapter 2, Projects and Tasks (Overview) to label and separate workloads, you can monitor resource consumption by each workload. You can use the extended accounting subsystem to capture a detailed set of resource consumption statistics on both processes and tasks.
The following topics are covered in this chapter.
To begin using extended accounting, see How to Activate Extended Accounting for Processes, Tasks, and Flows.
Introduction to Extended Accounting
The extended accounting subsystem labels usage records with the project for which the work was done. You can also use extended accounting, in conjunction with the Internet Protocol Quality of Service (IPQoS) flow accounting module described in Chapter 36, "Using Flow Accounting and Statistics Gathering (Tasks)," in System Administration Guide: IP Services, to capture network flow information on a system.
Before you can apply resource management mechanisms, you must first be able to characterize the resource consumption demands that various workloads place on a system. The extended accounting facility in the Solaris Operating System provides a flexible way to record system and network resource consumption on a task or process basis, or on the basis of selectors provided by the IPQoS flowacct module. For more information, see ipqos(7IPP).
Unlike online monitoring tools, which enable you to measure system usage in real time, extended accounting enables you to examine historical usage. You can then make assessments of capacity requirements for future workloads.
With extended accounting data available, you can develop or purchase software for resource chargeback, workload monitoring, or capacity planning.
How Extended Accounting Works
The extended accounting facility in the Solaris Operating System uses a versioned, extensible file format to contain accounting data. Files that use this data format can be accessed or be created by using the API provided in the included library, libexacct (see libexacct(3LIB)). These files can then be analyzed on any platform with extended accounting enabled, and their data can be used for capacity planning and chargeback.
If extended accounting is active, statistics are gathered that can be examined by the libexacct API. libexacct allows examination of the exacct files either forward or backward. The API supports third-party files that are generated by libexacct as well as those files that are created by the kernel. There is a Practical Extraction and Report Language (Perl) interface to libexacct that enables you to develop customized reporting and extraction scripts. See Perl Interface to libexacct.
With extended accounting enabled, the task tracks the aggregate resource usage of its member processes. A task accounting record is written at task completion. Interim records on running processes and tasks can also be written. For more information on tasks, see Chapter 2, Projects and Tasks (Overview).
Figure 4-1 Task Tracking With Extended Accounting Activated
Extensible Format
The extended accounting format is substantially more extensible than the SunOS™ legacy system accounting software format (see "What is System Accounting?" in System Administration Guide: Advanced Administration). Extended accounting permits accounting metrics to be added and removed from the system between releases, and even during system operation.
Note - Both extended accounting and legacy system accounting software can be active on your system at the same time.
exacct Records and Format
Routines that allow exacct records to be created serve two purposes.
To enable third-party exacct files to be created.
To enable the creation of tagging records to be embedded in the kernel accounting file by using the putacct system call (see getacct(2)).
Note - The putacct system call is also available from the Perl interface.
The format permits different forms of accounting records to be captured without requiring that every change be an explicit version change. Well-written applications that consume accounting data must ignore records they do not understand.
The libexacct library converts and produces files in the exacct format. This library is the only supported interface to exacct format files.
Note - The getacct, putacct, and wracct system calls do not apply to flows. The kernel creates flow records and writes them to the file when IPQoS flow accounting is configured.
Using Extended Accounting on a Solaris System with Zones Installed
The extended accounting subsystem collects and reports information for the entire system (including non-global zones) when run in the global zone. The global administrator can also determine resource consumption on a per-zone basis. See Extended Accounting on a Solaris System With Zones Installed for more information.
Extended Accounting Configuration
The /etc/acctadm.conf file contains the current extended accounting configuration. The file is edited through the acctadm interface, not by the user.
The directory /var/adm/exacct is the standard location for placing extended accounting data. You can use the acctadm command to specify a different location for the process and task accounting-data files. See acctadm(1M) for more information.
Commands Used With Extended Accounting
Command Reference | Description |
|---|---|
acctadm(1M) | Modifies various attributes of the extended accounting facility, stops and starts extended accounting, and is used to select accounting attributes to track for processes, tasks, and flows. |
wracct(1M) | Writes extended accounting records for active processes and active tasks. |
lastcomm(1) | Displays previously invoked commands. lastcomm can consume either standard accounting-process data or extended-accounting process data. |
For information on commands that are associated with tasks and projects, see Example Commands and Command Options. For information on IPQoS flow accounting, see ipqosconf(1M).
Perl Interface to libexacct
The Perl interface allows you to create Perl scripts that can read the accounting files produced by the exacct framework. You can also create Perl scripts that write exacct files.
The interface is functionally equivalent to the underlying C API. When possible, the data obtained from the underlying C API is presented as Perl data types. This feature makes accessing the data easier and it removes the need for buffer pack and unpack operations. Moreover, all memory management is performed by the Perl library.
The various project, task, and exacct-related functions are separated into groups. Each group of functions is located in a separate Perl module. Each module begins with the Sun standard Sun::Solaris:: Perl package prefix. All of the classes provided by the Perl exacct library are found under the Sun::Solaris::Exacct module.
The underlying libexacct(3LIB) library provides operations on exacct format files, catalog tags, and exacct objects. exacct objects are subdivided into two types:
Items, which are single-data values (scalars)
Groups, which are lists of Items
The following table summarizes each of the modules.
Module (should not contain spaces) | Description | For More Information |
|---|---|---|
Sun::Solaris::Project | This module provides functions to access the project manipulation functions getprojid(2), endprojent(3PROJECT) , fgetprojent(3PROJECT), getdefaultproj(3PROJECT), getprojbyid(3PROJECT), getprojbyname(3PROJECT), getprojent(3PROJECT), getprojidbyname(3PROJECT), inproj(3PROJECT), project_walk(3PROJECT), setproject(3PROJECT) , and setprojent(3PROJECT). | Project(3PERL) |
Sun::Solaris::Task | This module provides functions to access the task manipulation functions gettaskid(2) and settaskid(2). | Task(3PERL) |
Sun::Solaris::Exacct | This module is the top-level exacct module. This module provides functions to access the exacct-related system calls getacct(2), putacct(2), and wracct(2). This module also provides functions to access the libexacct(3LIB) library function ea_error(3EXACCT). Constants for all of the exacct EO_*, EW_*, EXR_*, P_*, and TASK_* macros are also provided in this module. | Exacct(3PERL) |
Sun::Solaris::Exacct:: Catalog | This module provides object-oriented methods to access the bitfields in an exacct catalog tag. This module also provides access to the constants for the EXC_*, EXD_*, and EXD_* macros. | Exacct::Catalog(3PERL) |
Sun::Solaris::Exacct:: File | This module provides object-oriented methods to access the libexacct accounting file functions ea_open(3EXACCT), ea_close(3EXACCT), ea_get_creator(3EXACCT), ea_get_hostname(3EXACCT), ea_next_object(3EXACCT), ea_previous_object(3EXACCT), and ea_write_object(3EXACCT). | Exacct::File(3PERL) |
Sun::Solaris::Exacct:: Object | This module provides object-oriented methods to access an individual exacct accounting file object. An exacct object is represented as an opaque reference blessed into the appropriate Sun::Solaris::Exacct::Object subclass. This module is further subdivided into the object types Item and Group. At this level, there are methods to access the ea_match_object_catalog(3EXACCT) and ea_attach_to_object(3EXACCT) functions. | Exacct::Object(3PERL) |
Sun::Solaris::Exacct:: Object::Item | This module provides object-oriented methods to access an individual exacct accounting file Item. Objects of this type inherit from Sun::Solaris::Exacct::Object. | Exacct::Object::Item(3PERL) |
Sun::Solaris::Exacct:: Object::Group | This module provides object-oriented methods to access an individual exacct accounting file Group. Objects of this type inherit from Sun::Solaris::Exacct::Object. These objects provide access to the ea_attach_to_group(3EXACCT) function. The Items contained within the Group are presented as a Perl array. | Exacct::Object::Group(3PERL) |
Sun::Solaris::Kstat | This module provides a Perl tied hash interface to the kstat facility. A usage example for this module can be found in /bin/kstat, which is written in Perl. | Kstat(3PERL) |
For examples that show how to use the modules described in the previous table, see Using the Perl Interface to libexacct.