Side-by-side comparison of PCP tools with legacy tools

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The article provides a side-by-side comparison of various PCP tools with other legacy tools, such as provided by sysstat, collectl and other basic tools. All PCP tools provide a common set of advanced features such as live monitoring (local or remote host), archive replay and many other features as described in PCPIntro(1).

Since all PCP data sources (live local host, live remote host or archive) have a uniform metrics namespace that include metadata (metric data type and semantics) associated with every metric name, generic tools such as pmrep(1), pmval(1), pminfo(1), pmprobe(1), and for graphical charts, pmchart(1), can be used to monitor arbitrary metrics with complete separation of the performance data source from the monitoring tool being used. These are extremely powerful features and in many cases completely removes the need to re-create various legacy tools because you can monitor the specific metrics you're interested in using any of the generic tools.

Nevertheless, it's useful to provide PCP equivalents of various common CLI tools since this is what most users are familiar with. PCP has well documented, stable APIs with bindings for C/C++, Python, Perl and also provides generic CLI tools such as pminfo, pmrep and pmprobe intended for use when scripting, so new tools and scripts are easy to develop using your programming language of choice.

This article is intended to complement How does Performance Co-Pilot (PCP) compare with sysstat, which provides more of an architectural comparison between sysstat and PCP. Note that in the table below, commands such as "pcp free" are launched by /usr/bin/pcp (in much the same was as e.g. lvm, git and perf can launch sub-commands). See pcp(1) for more details and the relevant pcp-XXX man page, e.g. pcp-free(1). Finally, note that most PCP man pages and other documentation are shipped in the pcp-doc package, so you will probably want to install that.

Legacy Tool PCP Tool Notes / Comments References
iostat pmiostat I/O statistics - the columns in the pmiostat report are similar to iostat -x see pmiostat(1)
iostat pmchart -c Iostat this is the graphical chart equivalent to pmiostat see pmchart(1). The 'Iostat' view is available in pcp-gui-3.11.2-1 and later
dmstat pmiostat -x dm pmiostat can monitor device-mapper devices (LVM, multipath, etc) and will map between the dm-XX non-persistent names to the persistent logical device names see pmiostat(1). dmstat has additional features such as region/offset specific monitoring of LVM devices based on PV boundaries in underlying VGs, but only monitors LVM devices, which is a subset of all DM devices such as devicew-mapper-multipath devices, dm-cache devices, etc.
free pcp free pcp-free provides a basic memory usage report see pcp-free(1).
numastat pcp numastat pcp-numastat prints numa statistics and numa topology see pcp-numastat(1)
uptime pcp uptime pcp-uptime prints the load average and uptime time since boot see pcp-uptime(1)
vmstat pcp vmstat pcp-vmstat provides a very similar report to vmstat see pcp-vmstat(1)
mpstat pmstat pmstat is similar. For graphical CPU monitoring, use pmchart -c CPU or pmchart -c Overview see pmstat(1) and pmchart(1)
mpstat pcp mpstat pcp-mpstat is currently under development no references yet
netstat -a pmrep use pmrep with appropriate network metrics (e.g. metrics below network.tcp and network.udp in the namespace) see pmrep(1)
netstat -s pminfo -f network will list all network metrics with current value (with no rate conversion of counters). pmrep or pmval can also be used if you want rate conversion see pmval(1), pmrep(1) and pminfo(1) and also run pminfo -t network to list available metrics with basic descriptive help text
netstat -i pmrep network.interface.{in,out}.bytes Append other network.* metrics to the pmrep command line, depending on what you want to monitor see pmrep(1)
ipcs pcp ipcs pcp-ipcs command line options are pretty much compatible with ipcs itself. see pcp-ipcs(1)
ps pminfo -f proc.psinfo or pmrep proc.psinfo.pid proc.psinfo.utime ... etc. Choose the metrics you're interested in see pmrep(1)
pidstat pcp pidstat pcp-pidstat reports per-process metrics (block process analysis development underway) pcp-3.11.4-1 and later, see pcp-pidstat(1)
atop pcp atop pcp-atop is a port of the actual atop source to the PCP APIs see pcp-atop(1)
collectl -D pmlogger and pmmgr the pmlogger service is PCP's data logger. PCP can also convert collectl raw logs into PCP archives using the collectl2pcp tool. An alternative data logging service is pmmgr, which is particularly useful for setting up a centralized logging "farm" See pmlogger(1), pmlogger_daily(1), collectl2pcp(1) and pmmgr(1)
collectl pcp collectl and generic tools pcp-collectl provides a subset of the collectl client options. Generic PCP monitor tools can also be used of course. see pcp-collectl(1), pmrep(1), pmval(1), pminfo(1), pmprobe(1), pmchart(1), etc.
sar -A pcp atopsar -A pcp-atopsar is similar to sar -A see pcp-atopsar(1)
sadc pmlogger the pmlogger service is PCP's data logger. chkconfig pmlogger on; service pmlogger start See pmlogger(1) and pmlogger_daily(1)
tapestat pcp tapestat, pmrep, pmchart support for scsi tape statistics was added to the PCP Linux agent in version 3.11.8-1 and later. The metrics to monitor are below tape.dev in the PCP namespace pcp tapestat(1) is available in pcp, or you can use pmrep(1) or pmchart(1) to monitor scsi tape statistics with the tape.dev.* metrics.
iotop pcp atop pcp-atop, pmrep, pmval, pmchart and other PCP tools can provide per-process I/O stats see related man pages, particularly pcp-atop(1)
htop pcp htop pcp-htop is currently under development no reference available yet
top pcp atop pcp-atop provides similar functionality to top see pcp-atop(1)
systemtap pmevent, pmdammv, pmdajson Event data can be viewed using the pmevent tool and other generic tools. PCP can import systemtap event data through the pmdajson agent - this is an advanced feature. PCP also has pmdammv (Memory Mapped Values agent) which can export metrics from suitably instrumented applications see pmevent(1), PMAPI(3), PCPIntro(1), pmdammv(1), pmdajson(1) and related documentation
ceph generic PCP services enabled on each ceph node A dedicated ceph agent is work in progress. For now, you can monitor each ceph node in a cluster using generic tools such as pmchart, etc. For this you would need to install pcp and enable the pmcd service on each ceph node in the cluster. You can also set up centralized logging using e.g. pmmgr, which will log all nodes in a ceph cluster see pmchart(1), pmmgr(1), pmlogger(1) and other generic tools, and the relevant ceph documentation

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