PMCONNECTLOGGER(3)					     Library Functions Manual						PMCONNECTLOGGER(3)

NAME

       __pmConnectLogger - connect to a performance metrics logger control port

C SYNOPSIS

       #include <pcp/pmapi.h>
       #include <pcp/impl.h>

       int __pmConnectLogger(const char *hostname, int pid);

       cc ... -lpcp

DESCRIPTION

       Each  instance  of  the	Performance  Co-Pilot  (PCP) archive logger program pmlogger(1) supports a control port on which __pmControlLog(3)
       requests are received, and responses sent.  Optionally, the pmlogger(1) instance may be designated the ``primary'' logger.

       __pmConnectLogger may be used to establish a control port connection to the pmlogger(1) instance identified by process id pid on  the  host
       hostname.

       One  special  case  is supported; for the reserved pid value of PM_LOG_CONTROL_PORT the requested connection is to the control port for the
       ``primary'' logger, whatever its process id might be.

       On success, __pmConnectLogger returns a non-negative integer, that is a file descriptor that may be used in subsequent  communication  with
       the pmlogger(1) instance, e.g. for __pmControlLog(3).

       As the control port to pmlogger(1) is not mulitplexed, applications using __pmConnectLogger should use close(2) to terminate the connection
       to pmlogger(1) as soon as they have finished communicating.

       If the application connects, and the pmlogger(1) instance subsequently terminates, e.g. because the associated pmcd(1) instance	is  termi-
       nated,  the  application  will have to explicitly re-establish connection to a re-started pmlogger(1) instance by calling __pmConnectLogger
       again.

SEE ALSO

       pmcd(1), pmlc(1), pmlogger(1), PMAPI(3) and __pmControlLog(3).

DIAGNOSTICS

       PM_ERR_PERMISSION
	      no permission to connect to the specified pmlogger(1) instance

       -ECONNREFUSED
	      the designated pmlogger(1) instance does not exist

       -EEADDRINUSE
	      the requested control port is already in use

Performance Co-Pilot							PCP							PMCONNECTLOGGER(3)