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Diffstat (limited to 'src/pmdas/systemtap/pmdasystemtap.pl')
| -rw-r--r-- | src/pmdas/systemtap/pmdasystemtap.pl | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/src/pmdas/systemtap/pmdasystemtap.pl b/src/pmdas/systemtap/pmdasystemtap.pl new file mode 100644 index 0000000..801b788 --- /dev/null +++ b/src/pmdas/systemtap/pmdasystemtap.pl @@ -0,0 +1,168 @@ +# +# Copyright (c) 2012 Red Hat. +# Copyright (c) 2008 Aconex. All Rights Reserved. +# +# This program is free software; you can redistribute it and/or modify it +# under the terms of the GNU General Public License as published by the +# Free Software Foundation; either version 2 of the License, or (at your +# option) any later version. +# +# This program is distributed in the hope that it will be useful, but +# WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY +# or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +# for more details. +# + +use strict; +use warnings; +use PCP::PMDA; + +use vars qw( $pmda $id ); +my $probe_indom = 0; +my $probe_script = pmda_config('PCP_PMDAS_DIR') . '/systemtap/probes.stp'; +my $probe_command = "/usr/bin/stap -m pmdasystemtap $probe_script"; +my @probe_instances = ( 0 => 'sync', 1 => 'readdir' ); +my ( $sync_count, $sync_pid, $sync_cmd ) = ( 0, 0, "(none)" ); +my ( $readdir_count, $readdir_pid, $readdir_cmd ) = ( 0, 0, "(none)" ); + +sub systemtap_input_callback +{ + ( $id, $_ ) = @_; + # $pmda->log($_); + + if (/^readdir: \((\d+)\) (.*)$/) { + ( $readdir_pid, $readdir_cmd ) = ( $1, $2 ); + $readdir_count++; + } + elsif (/^sync: \((\d+)\) (.*)$/) { + ( $sync_pid, $sync_cmd ) = ( $1, $2 ); + $sync_count++; + } +} + +sub systemtap_fetch_callback +{ + my ($cluster, $item, $inst) = @_; + + if ($inst < 0 || $inst > 1) { return (PM_ERR_INST, 0); } + if ($cluster == 0) { + if ($item == 0) { + if ($inst == 0) { return ($sync_count, 1); } + else { return ($readdir_count, 1); } + } + elsif ($item == 1) { + if ($inst == 0) { return ($sync_pid, 1); } + else { return ($readdir_pid, 1); } + } + elsif ($item == 2) { + if ($inst == 0) { return ($sync_cmd, 1); } + else { return ($readdir_cmd, 1); } + } + } + return (PM_ERR_PMID, 0); +} + +$pmda = PCP::PMDA->new('systemtap', 88); + +$pmda->add_metric(pmda_pmid(0,0), PM_TYPE_U32, $probe_indom, + PM_SEM_COUNTER, pmda_units(0,0,1,0,0,PM_COUNT_ONE), + 'systemtap.probes.count', + 'Number of times the probe has been observed', ''); +$pmda->add_metric(pmda_pmid(0,1), PM_TYPE_32, $probe_indom, + PM_SEM_INSTANT, pmda_units(0,0,0,0,0,0), + 'systemtap.probes.pid', + 'The PID of the last process to pass the probe point', ''); +$pmda->add_metric(pmda_pmid(0,2), PM_TYPE_STRING, $probe_indom, + PM_SEM_INSTANT, pmda_units(0,0,0,0,0,0), + 'systemtap.probes.cmd', + 'The name of the last process to pass the probe point', ''); + +$pmda->add_indom($probe_indom, \@probe_instances, + 'Instance domain exporting each SystemTap probe', ''); + +$pmda->set_fetch_callback(\&systemtap_fetch_callback); +$pmda->add_pipe($probe_command, \&systemtap_input_callback, 0); +$pmda->set_user('pcp'); +$pmda->run; + +=pod + +=head1 NAME + +pmdasystemtap - Systemtap performance metrics domain agent (PMDA) + +=head1 DESCRIPTION + +B<pmdasystemtap> is a Performance Metrics Domain Agent (PMDA) which exports +metric values from the Linux Systemtap dynamic tracing toolkit. + +This implementation uses the stap(1) tool, which is a front-end to +the Systemtap toolkit. + +=head1 INSTALLATION + +In order to access performance data exported by Systemtap from +with PCP, it is necessary to perform two configuration steps: + +=over + +=item 1. + +Configure Systemtap probes, and verify them with stap(1). +These should be produced in a format that is easily parsed, +and then stored in the $PCP_PMDAS_DIR/systemtap/probes.stp +file. + +=item 2. + +Configure B<pmdasystemtap> to extract the values from the text +produced by stap. Two example probes are implemented in the +default systemtap PMDA script - readdir and sync traces (see +$PCP_PMDAS_DIR/systemtap/pmdasystemtap.pl for details). + +=back + + # cd $PCP_PMDAS_DIR/systemtap + # [ edit probes.stp, test /usr/bin/stap probes.stp ] + # [ edit pmdasystemtap.pl ] + +Once this is setup, you can access the names and values for the +systemtap performance metrics by doing the following as root: + + # cd $PCP_PMDAS_DIR/systemtap + # ./Install + +If you want to undo the installation, do the following as root: + + # cd $PCP_PMDAS_DIR/systemtap + # ./Remove + +B<pmdasystemtap> 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. + +=head1 FILES + +=over + +=item $PCP_PMDAS_DIR/systemtap/probes.stp + +probe configuration file for stap(1), run by B<pmdasystemtap> + +=item $PCP_PMDAS_DIR/systemtap/Install + +installation script for the B<pmdasystemtap> agent + +=item $PCP_PMDAS_DIR/systemtap/Remove + +undo installation script for the B<pmdasystemtap> agent + +=item $PCP_LOG_DIR/pmcd/systemtap.log + +default log file for error messages from B<pmdasystemtap> + +=back + +=head1 SEE ALSO + +pmcd(1) and stap(1). |