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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 2020-12-18.
(At that time, the date of the most recent commit that was found
in the repository was 2020-12-18.) 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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