Tribblix: manual page: rcapstat.1

RCAPSTAT(1) User Commands RCAPSTAT(1)

NAME

rcapstat - report resource cap enforcement daemon statistics

SYNOPSIS

rcapstat [-g] [-p | -z] [-T u | d ] [interval [count]]

DESCRIPTION

The rcapstat command reports on the projects or zones capped by
rcapd(8). Each report contains statistics that pertain to the project
or zone and paging statistics. Paging refers to the act of relocating
portions of memory, called pages, to or from physical memory. rcapd
pages out the most infrequently used pages.

The paging statistics in the first report issued show the activity
since the daemon was started. Subsequent reports reflect the activity
since the last report was issued.

Reports are issued every interval seconds up to the quantity
specified by count, or forever if count is not specified.

OPTIONS

The following options are supported:

-g
Global statistics. Reports the minimum memory utilization
for memory cap enforcement (see rcapadm(8)) and reports
current memory utilization as a percentage of installed
physical memory.

-p
Report statistics for capped projects. This is the
default if no option is specified.

-T u | d
Display a time stamp.

Specify u for a printed representation of the internal
representation of time. See time(2). Specify d for
standard date format. See date(1).

-z
Report statistics for capped zones.

OUTPUT

The following list defines the column headings in the rcapstat report
and provides information about how to interpret the report.

id
The project ID or zone ID of the capped project or zone.

project
The project name.

zone
The zone name.

nproc
The number of processes in the project or zone since the
last report.

vm
The total virtual memory size of the project or zone's
processes, including all mapped files and devices, in
kilobytes (K), megabytes (M), or gigabytes (G).

rss
The total resident set size (RSS) of the project or zone's
processes, in kilobytes (K), megabytes (M), or gigabytes
(G). The count does not account for shared pages.

cap
The RSS cap for the project or zone. See rcapd(8) for
information about how to specify memory caps.

at
The total amount of memory that rcapd attempted to page
out.

Paging refers to the act of relocating portions of memory,
called pages, to or from physical memory. rcapd pages out
the most infrequently used pages.

avgat
The average amount of memory that rcapd attempted to page
out during each sample cycle. The rate at which rcapd
samples RSS can be set with rcapadm(8).

pg
An estimate of the total amount of memory that rcapd
successfully paged out.

avgpg
An estimate of the average amount of memory that rcapd
successfully paged out during each sample cycle. The rate
at which rcapd samples process RSS sizes can be set with
rcapadm.

OPERANDS

The following operands are supported:

interval
Specifies the reporting interval in seconds. The default
interval is 5 seconds.

count
Specifies the number of reports to produce. By default,
rcapstat reports statistics until a termination signal is
received or until the rcapd process exits.

EXAMPLES

Example 1: Using rcapstat to Report Cap and Project Information

Caps are defined for two projects associated with two users. user1
has a cap of 50 megabytes and user2 has a cap of 10 megabytes.

The following command produces five reports at 5-second sampling
intervals.

example# rcapstat 5 5
id project nproc vm rss cap at avgat pg avgpg
112270 user1 24 123M 35M 50M 50M 0K 3312K 0K
78194 user2 1 2368K 1856K 10M 0K 0K 0K 0K
id project nproc vm rss cap at avgat pg avgpg
112270 user1 24 123M 35M 50M 0K 0K 0K 0K
78194 user2 1 2368K 1856K 10M 0K 0K 0K 0K
id project nproc vm rss cap at avgat pg avgpg
112270 user1 24 123M 35M 50M 0K 0K 0K 0K
78194 user2 1 2368K 1928K 10M 0K 0K 0K 0K
id project nproc vm rss cap at avgat pg avgpg
112270 user1 24 123M 35M 50M 0K 0K 0K 0K
78194 user2 1 2368K 1928K 10M 0K 0K 0K 0K
id project nproc vm rss cap at avgat pg avgpg
112270 user1 24 123M 35M 50M 0K 0K 0K 0K
78194 user2 1 2368K 1928K 10M 0K 0K 0K 0K

The first three lines of output constitute the first report, which
contains the cap and project information for the two projects and
paging statistics since rcapd was started. The at and pg columns are
a number greater than zero for user1 and zero for user2, which
indicates that at some time in the daemon's history, user1 exceeded
its cap but user2 did not.

The subsequent reports show no significant activity.

Example 2: Using rcapstat to Monitor the RSS of a Project

example% rcapstat 5 5
id project nproc vm rss cap at avgat pg avgpg
376565 user1 57 209M 46M 10M 440M 220M 5528K 2764K
376565 user1 57 209M 44M 10M 394M 131M 4912K 1637K
376565 user1 56 207M 43M 10M 440M 147M 6048K 2016K
376565 user1 56 207M 42M 10M 522M 174M 4368K 1456K
376565 user1 56 207M 44M 10M 482M 161M 3376K 1125K

The project user1 has an RSS in excess of its physical memory cap.
The nonzero values in the pg column indicate that rcapd is
consistently paging out memory as it attempts to meet the cap by
lowering the physical memory utilization of the project's processes.
However, rcapd is unsuccessful, as indicated by the varying rss
values that do not show a corresponding decrease. This means that the
application's resident memory is being actively used, forcing rcapd
to affect the working set. Under this condition, the system continues
to experience high page fault rates, and associated I/O, until the
working set size (WSS) is reduced, the cap is raised, or the
application changes its memory access pattern. Notice that a page
fault occurs when either a new page must be created, or the system
must copy in a page from the swap device.

Example 3: Determining the Working Set Size of a Project

This example is a continuation of Example 1, and it uses the same
project.

example% rcapstat 5 5
id project nproc vm rss cap at avgat pg avgpg
376565 user1 56 207M 44M 10M 381M 191M 15M 7924K
376565 user1 56 207M 46M 10M 479M 160M 2696K 898K
376565 user1 56 207M 46M 10M 424M 141M 7280K 2426K
376565 user1 56 207M 43M 10M 401M 201M 4808K 2404K
376565 user1 56 207M 43M 10M 456M 152M 4800K 1600K
376565 user1 56 207M 44M 10M 486M 162M 4064K 1354K
376565 user1 56 207M 52M 100M 191M 95M 1944K 972K
376565 user1 56 207M 55M 100M 0K 0K 0K 0K
376565 user1 56 207M 56M 100M 0K 0K 0K 0K
376565 user1 56 207M 56M 100M 0K 0K 0K 0K
376565 user1 56 207M 56M 100M 0K 0K 0K 0K
376565 user1 56 207M 56M 100M 0K 0K 0K 0K

By inhibiting cap enforcement, either by raising the cap of a project
or by changing the minimum physical memory utilization for cap
enforcement (see rcapadm(8)), the resident set can become the working
set. The rss column might stabilize to show the project WSS, as shown
in the previous example. The WSS is the minimum cap value that allows
the project's processes to operate without perpetually incurring page
faults.

EXIT STATUS

The following exit values are returned:

0
Successful completion.

1
An error occurred.

2
Invalid command-line options were specified.

NOTES

If the interval specified to rcapstat is shorter than the reporting
interval specified to rcapd (with rcapadm(8)), the output for some
intervals can be zero. This is because rcapd does not update
statistics more frequently than the interval specified with rcapadm,
and this interval is independent of (and less precise than) the
sampling interval used by rcapstat.

June 16, 2009 RCAPSTAT(1)