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pmistart(3) [centos man page]

PMISTART(3)						     Library Functions Manual						       PMISTART(3)

NAME
pmiStart - establish a new LOGIMPORT context C SYNOPSIS
#include <pcp/pmapi.h> #include <pcp/impl.h> #include <pcp/import.h> int pmiStart(const char *archive, int inherit); cc ... -lpcp_import -lpcp Perl SYNOPSIS use PCP::LogImport; pmiStart($archive, $inherit); DESCRIPTION
As part of the Performance Co-Pilot Log Import API (see LOGIMPORT(3)), pmiStart creates a new context. Each context maintains the follow- ing state and metadata: o The base name (archive) for the physical files that constitute the output PCP archive. o The source hostname for the data that will be written to the PCP archive. Defaults to the hostname of the localhost, but can be set using pmiSetHostname(3). o The source timezone for the PCP archive. Defaults to the timezone of the localhost, but can be set using pmiSetTimezone(3). o Metrics and instance domains, as defined by pmiAddMetric(3). o Instances for each instance domain, as defined by pmiAddInstance(3). o Handles as defined by pmiGetHandle(3). Each handle is a metric-instance pair, and each metric-instance pair may have an associated value in each record written to the output PCP archive. o An optional set of data values for one or more metric-instance pairs (ready for the next record to be written to the output PCP archive) as defined by calls to pmPutValue(3) or pmPutValuehandle(3). If inherit is true, then the new context will inherit any and all metadata (metrics, instance domains, instances and handles) from the cur- rent context, otherwise the new context is created with no metadata. The basename for the output PCP archive, the source hostname, the source timezone and any data values from the current context are not inherited. If this is the first call to pmiStart the metadata will be empty independent of the value of inherit. Since no physical files for the output PCP archive will be created until the first call to pmiWrite(3) or pmiPutRecord(3), archive could be NULL to create a convenience context that is populated with metadata to be inherited by subsequent contexts. The return value is a context identifier that could be used in a subsequent call to pmUseContext(3) and the new context becomes the current context which persists for all subsequent calls up to either another pmiStart call or a call to pmiUseContext(3) or a call to pmiEnd(3). DIAGNOSTICS
It is an error if the physical files archive.0 and/or archive.index and/or archive.meta already exist, but this is not discovered until the first attempt is made to output some data by calling pmiWrite(3) or pmiPutRecord(3), so pmiStart always returns a positive context identi- fier. SEE ALSO
LOGIMPORT(3), pmiAddInstance(3), pmiAddMetric(3), pmiEnd(3), pmiErrStr(3), pmiGetHandle(3), pmiPutResult(3), pmiPutValue(3), pmiPutValue- Handle(3), pmiSetHostname(3), pmiSetTimezone(3), pmiUseContext(3) and pmiWrite(3). Performance Co-Pilot PMISTART(3)

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PMGETARCHIVEEND(3)					     Library Functions Manual						PMGETARCHIVEEND(3)

NAME
pmGetArchiveEnd - locate logical end of file for an archive log C SYNOPSIS
#include <pcp/pmapi.h> int pmGetArchiveEnd(struct timeval *tvp); cc ... -lpcp DESCRIPTION
Assuming the current PMAPI context is associated with an archive log, pmGetArchiveEnd will attempt to find the logical end of file (after the last complete record in the archive), and return the last recorded timestamp via tvp. This timestamp may be passed to pmSetMode(3) to reliably position the context at the last valid log record, e.g. in preparation for subsequent reading in reverse chronological order. For archive logs that are not concurrently being written, the physical end of file and the logical end of file are co-incident. However if an archive log is being written by pmlogger(1) at the same time an application is trying to read the archive, the logical end of file may be before the physical end of file due to write buffering that is not aligned with the logical record boundaries. pmGetArchiveEnd returns an error less than zero if the context is neither valid, nor associated with an archive, or the archive is seri- ously corrupted. Otherwise, the return value is 0 if there has been no change of state since the last call, or 1 if the logical end of file has advanced since the last call. In the absence of an error, the result returned via tvp is well-defined. pmGetArchiveEnd preserves the positioning state of the log file prior to this function call. PCP ENVIRONMENT
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 configura- tion file, as described in pcp.conf(5). Values for these variables may be obtained programmatically using the pmGetConfig(3) function. SEE ALSO
PMAPI(3), pmFetch(3), pmFetchArchive(3), pmGetArchiveLabel(3), pmGetConfig(3), pmSetMode(3), pcp.conf(5) and pcp.env(5). DIAGNOSTICS
PM_ERR_NOCONTEXT the current PMAPI context is either invalid, or not associated with an archive log PM_ERR_LOGREC the archive is sufficiently damaged, that not a single valid record can be found Performance Co-Pilot PCP PMGETARCHIVEEND(3)
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