__pmConnectLogger(3) — Linux manual page


PMCONNECTLOGGER(3)        Library Functions Manual        PMCONNECTLOGGER(3)

NAME         top

       __pmConnectLogger  -  connect to a performance metrics logger control

C SYNOPSIS         top

       #include "pmapi.h"
       #include "libpcp.h"

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

       cc ... -lpcp

CAVEAT         top

       This documentation is intended for internal Performance Co-Pilot
       (PCP) developer use.

       These interfaces are not part of the PCP APIs that are guaranteed to
       remain fixed across releases, and they may not work, or may provide
       different semantics at some point in the future.

DESCRIPTION         top

       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

       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

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

SEE ALSO         top

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

DIAGNOSTICS         top

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

              the designated pmlogger(1) instance does not exist

              the requested control port is already in use

COLOPHON         top

       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
       2020-09-18.  (At that time, the date of the most recent commit that
       was found in the repository was 2020-09-18.)  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

Performance Co-Pilot                 PCP                  PMCONNECTLOGGER(3)

Pages that refer to this page: __pmcontrollog(3)__pmControlLog(3)