pmlocalpmda(3) [centos man page]
PMLOCALPMDA(3) Library Functions Manual PMLOCALPMDA(3) NAME
__pmLocalPMDA - change the table of DSO PMDAs for PM_CONTEXT_LOCAL contexts C SYNOPSIS
#include <pcp/pmapi.h> #include <pcp/impl.h> int __pmLocalPMDA(int op, int domain, const char *name, const char *init); cc ... -lpcp DESCRIPTION
PCP contexts of type PM_CONTEXT_LOCAL are used by clients that wish to fetch metrics directly from one or more PMDAs on the local host without involving pmcd(1). A PMDA that is to be used in this way must have been built as a Dynamic Shared Object (DSO). Historically the table of PMDAs available for use with PM_CONTEXT_LOCAL was hardcoded to the following: * The PMDA (or PMDAs) that export the operating system performance data and data about process activity. * The mmv PMDA. * The sample PMDA provided $PCP_LITE_SAMPLE or $PMDA_LOCAL_SAMPLE is set in the environment - used mostly for QA and testing. The initial table of PMDAs available for use with PM_CONTEXT_LOCAL is now generated dynamically from all those PMDAs that have been in- stalled as DSOs on the local host. The one exception is the ``pmcd'' PMDA which only operates correctly in the address space of a running pmcd(1) process and so is not available to an application using a PM_CONTEXT_LOCAL context. __pmLocalPMDA provides a number of services to amend the table of PMDAs available for use with PM_CONTEXT_LOCAL. The op argument specifies the what should be done and takes one of the following values and actions: PM_LOCAL_ADD Append an entry to the table for the PMDA with a Performance Metrics Domain (PMD) of domain, the path to the DSO PMDA is given by path and the PMDA's initialization routine is init. PM_LOCAL_DEL Removes all entries in the table where the domain matches, or the path matches. Setting the arguments domain to -1 or path to NULL to force matching on the other argument. The init argument is ignored. PM_LOCAL_CLEAR Remove all entries from the table. All the other arguments are ignored in this case. The domain, name and init arguments have similar syntax and semantics to the associated fields in the pmcd(1) configuration file. The one difference is the path argument which is used by __pmLocalPMDA to find a likely looking DSO by searching in this order: $PCP_PM- DAS_DIR/path, path, $PCP_PMDAS_DIR/path.dso-suffix and finally path.dso-suffix (dso-suffix is the local platform specific default file name suffix for a DSO, e.g. so for Linux, dylib for Mac OS X, dll for Windows, etc.). RETURN VALUE
In most cases, __pmLocalPMDA returns 0 to indicate success. If op is invalid, then the return value is PM_ERR_CONV else if there is no matching table entry found for a PM_LOCAL_DEL operation, PM_ERR_INDOM is returned. SEE ALSO
pmcd(1), PMAPI(3), pmNewContext(3) and __pmSpecLocalPMDA(3). Performance Co-Pilot PMLOCALPMDA(3)
Check Out this Related Man Page
PMDASAMPLE(1) General Commands Manual PMDASAMPLE(1) NAME
pmdasample - sample performance metrics domain agent (PMDA) SYNOPSIS
$PCP_PMDAS_DIR/pmdasample [-d domain] [-i port] [-l logfile] [-p] [-u socket] [-U username] DESCRIPTION
pmdasample is a sample Performance Metrics Domain Agent (PMDA) which exports a variety of synthetic performance metrics. This PMDA was developed as part of the quality assurance testing for the PCP product, but has other uses, most notably in the development of new PCP clients. The metrics exported by the sample PMDA cover the full range of data types, data semantics, value cardinality, instance domain stability and error conditions found in real PMDAs. A brief description of the pmdasample command line options follows: -d It is absolutely crucial that the performance metrics domain number specified here is unique and consistent. That is, domain should be different for every PMDA on the one host, and the same domain number should be used for the same PMDA on all hosts. -i Expect PMCD to connect to pmdasample on the specified TCP/IP port. port may be a port number or port name. -l Location of the log file. By default, a log file named sample.log is written in the current directory of pmcd(1) when pmdasample is started, i.e. $PCP_LOG_DIR/pmcd. If the log file cannot be created or is not writable, output is written to the standard error instead. -p Expect PMCD to create a pipe and the connection to pmdasample is via standard input and standard output. This is the default connec- tion mode. -u Expect PMCD to connect to pmdasample on the Unix domain socket named socket. -U User account under which to run the agent. The default is the unprivileged "pcp" account in current versions of PCP, but in older versions the superuser account ("root") was used by default. At most one of the options -i, -p and -u may be specified. INSTALLATION
If you want access to the names, help text and values for the sample performance metrics, do the following as root: # cd $PCP_PMDAS_DIR/sample # ./Install Note that the installation script also installs the DSO version of the sample PMDA, so there are in fact two PMDAs installed, and two sets of performance metrics, namely sample.* and sampledso.*. If you want to undo the installation (and remove both PMDAs), do the following as root: # cd $PCP_PMDAS_DIR/sample # ./Remove pmdasample is launched by pmcd(1) and should never be executed directly. The Install and Remove scripts notify pmcd(1) when the agent is installed or removed. FILES
$PCP_PMCDCONF_PATH command line options used to launch pmdasample $PCP_PMDAS_DIR/sample/help default help text file for the sample metrics $PCP_PMDAS_DIR/sample/Install installation script for the pmdasample agent $PCP_PMDAS_DIR/sample/Remove undo installation script for the pmdasample agent $PCP_LOG_DIR/pmcd/sample.log default log file for error messages and other information from pmdasample 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). SEE ALSO
PCPIntro(1), pmcd(1), pmdasimple(1), pmdatrivial(1), pmdatxmon(1), pcp.conf(5) and pcp.env(5). Performance Co-Pilot PCP PMDASAMPLE(1)