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NAME | C SYNOPSIS | DESCRIPTION | PCP ENVIRONMENT | SEE ALSO | DIAGNOSTICS | COLOPHON |
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PMGETARCHIVELABEL(3) Library Functions Manual PMGETARCHIVELABEL(3)
pmGetArchiveLabel - fetch the label record from a set of performance
metrics archive logs
#include <pcp/pmapi.h>
int pmGetArchiveLabel(pmLogLabel *lp);
cc ... -lpcp
Within the framework of the Performance Co-Pilot (PCP), archive logs
of performance metrics values may be accumulated and saved using the
program pmlogger(1).
The routine pmGetArchiveLabel may be used to fetch the label record
from a set of archive logs that has already been opened using
pmNewContext(3), or pmDupContext(3), and thereby associated with the
current Performance Metrics Application Programming Interface (PMAPI)
context.
The result returned via the pointer lp is a structure that must be
pre-allocated by the caller and has the following format (defined in
pmapi.h).
/*
* Label Record at the start of every log file
*/
typedef struct {
int ll_magic; /* PM_LOG_MAGIC | log format version no. */
pid_t ll_pid; /* PID of logger */
struct timeval ll_start;/* start of this log */
char ll_hostname[PM_LOG_MAXHOSTLEN]; /* name of collection host */
char ll_tz[40]; /* $TZ at collection host */
} pmLogLabel;
For an application, the most useful information from the archive
label is likely to be in the fields ll_start, ll_hostname or ll_tz.
Note that the size of the ll_hostname field is PM_LOG_MAXHOSTLEN (64
bytes) which is less than MAXHOSTNAMELEN (see gethostbyname(3)) on
some platforms. These semantics are necessary to retain backwards
compatibility with the PCP archive file format.
pmGetArchiveLabel returns zero for success.
Environment variables with the prefix PCP_ are used to parameterize
the file and directory names used by PCP. On each installation, the
file /etc/pcp.conf contains the local values for these variables.
The $PCP_CONF variable may be used to specify an alternative
configuration file, as described in pcp.conf(5). Values for these
variables may be obtained programmatically using the pmGetConfig(3)
function.
pmlogger(1), PMAPI(3), pmDupContext(3), pmGetConfig(3),
pmNewContext(3), pcp.conf(5) and pcp.env(5).
PM_ERR_NOCONTEXT
the current PMAPI context is either invalid, or not associated
with a set of archive logs
This page is part of the PCP (Performance Co-Pilot) project.
Information about the project can be found at ⟨http://www.pcp.io/⟩.
If you have a bug report for this manual page, send it to
pcp@groups.io. This page was obtained from the project's upstream
Git repository ⟨https://github.com/performancecopilot/pcp.git⟩ on
2018-02-02. (At that time, the date of the most recent commit that
was found in the repository was 2018-02-02.) If you discover any
rendering problems in this HTML version of the page, or you believe
there is a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
man-pages@man7.org
Performance Co-Pilot PCP PMGETARCHIVELABEL(3)
Pages that refer to this page: pmgetarchiveend(3), pmgetcontexthostname(3), __pmparsetime(3), pmparsetimewindow(3)
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