Resmon

Simple wrapper around sar(1), using EventEmitter.

Install

npm install resmon

Usage

var SAR = require('resmon');
var daemon = new SAR();
daemon.on('cpu', function(stat) {
  /* ... */
});
daemon.start(); //spawn `sar` process

Options

You can pass to SAR an optional interval parameter (emitter frequency, emit events every interval seconds), and an options object. Currently, the only valid option is the parameters array, which contains command line args to the sar process.

Default interval is 5, the default parameter is -A (fires all events).

var daemon = new SAR(1, {
  parameters: ['-b']
});
daemon.start();

The above example creates a SAR instance, which fires only the io event every seconds.

Events

For details, see man sar.

SAR instance emits objects, the keys are field names, the values are arrays, eg. if you have multiple CPU cores:

var SAR = require('resmon');
var daemon = new SAR();
daemon.on('cpu', function(stat) {
  console.log(stat['%usr'][0]);
  //display CPU utilization percentage (at user level) for all CPUs
  //usually the first row contains aggregated (sum, avg, etc.) values
});

cpu

Fields: CPU, %usr, %nice, %sys, %iowait, %steal, %irq, %soft, %guest, %idle

task

Fields: proc/s, cswch/s

int

Fields: INTR, intr/s

swapPages

Fields: pswpin/s, pswpout/s

page

Fields: pgpgin/s, pgpgout/s, fault/s, majflt/s, pgfree/s, pgscank/s, pgscand/s, pgsteal/s, %vmeff

io

Fields: tps, rtps, wtps, bread/s, bwrtn/s

memoryPages

Fields: frmpg/s, bufpg/s, campg/s

memory

Fields: kbmemfree, kbmemused, %memused, kbbuffers, kbcached, kbcommit, %commit, kbactive, kbinact

swap

Fields: kbswpfree, kbswpused, %swpused, kbswpcad, %swpcad

kernel

Fields: dentunusd, file-nr, inode-nr, pty-nr

load

Fields: runq-sz, plist-sz, ldavg-1, ldavg-5, ldavg-15, blocked

block

Fields: DEV, tps, rd_sec/s, wr_sec/s, avgrq-sz, avgqu-sz, await, svctm, %util

net:dev

Fields: IFACE, rxpck/s, txpck/s, rxkB/s, txkB/s, rxcmp/s, txcmp/s, rxmcst/s

net:edev

Fields: IFACE, rxerr/s, txerr/s, coll/s, rxdrop/s, txdrop/s, txcarr/s, rxfram/s, rxfifo/s, txfifo/s

net:nfs

Fields: call/s, retrans/s, read/s, write/s, access/s, getatt/s

net:nfsd

Fields: scall/s, badcall/s, packet/s, udp/s, tcp/s, hit/s, miss/s, sread/s, swrite/s, saccess/s, sgetatt/s

net:sock

Fields: totsck, tcpsck, udpsck, rawsck, ip-frag, tcp-tw

net:ip

Fields: irec/s, fwddgm/s, idel/s, orq/s, asmrq/s, asmok/s, fragok/s, fragcrt/s

net:eip

Fields: ihdrerr/s, iadrerr/s, iukwnpr/s, idisc/s, odisc/s, onort/s, asmf/s, fragf/s

net:icmp

Fields: imsg/s, omsg/s, iech/s, iechr/s, oech/s, oechr/s, itm/s, itmr/s, otm/s, otmr/s, iadrmk/s, iadrmkr/s, oadrmk/s, oadrmkr/s

net:eicmp

Fields: ierr/s, oerr/s, idstunr/s, odstunr/s, itmex/s, otmex/s, iparmpb/s, oparmpb/s, isrcq/s, osrcq/s, iredir/s, oredir/s

net:tcp

Fields: active/s, passive/s, iseg/s, oseg/s

net:etcp

Fields: atmptf/s, estres/s, retrans/s, isegerr/s, orsts/s

net:udp

Fields: idgm/s, odgm/s, noport/s, idgmerr/s

net:sock6

Fields: tcp6sck, udp6sck, raw6sck, ip6-frag

net:ip6

Fields: irec6/s, fwddgm6/s, idel6/s, orq6/s, asmrq6/s, asmok6/s, imcpck6/s, omcpck6/s, fragok6/s, fragcr6/s

net:eip6

Fields: ihdrer6/s, iadrer6/s, iukwnp6/s, i2big6/s, idisc6/s, odisc6/s, inort6/s, onort6/s, asmf6/s, fragf6/s, itrpck6/s

net:icmp6

Fields: imsg6/s, omsg6/s, iech6/s, iechr6/s, oechr6/s, igmbq6/s, igmbr6/s, ogmbr6/s, igmbrd6/s, ogmbrd6/s, irtsol6/s, ortsol6/s, irtad6/s, inbsol6/s, onbsol6/s, inbad6/s, onbad6/s

net:eicmp6

Fields: ierr6/s, idtunr6/s, odtunr6/s, itmex6/s, otmex6/s, iprmpb6/s, oprmpb6/s, iredir6/s, oredir6/s, ipck2b6/s, opck2b6/s

net:udp6

Fields: idgm6/s, odgm6/s, noport6/s, idgmer6/s

power:cpu

Fields: CPU, MHz

power:temp

Fields: TEMP, degC, %temp, DEVICE

power:freq

Fields: CPU, wghMHz

UNKNOWN

If sar output can be parsed, but the mapping for the event is missing, UNKNOWN event is emitted, with the parsed object.

error

If sar output cannot be parsed, error is emitted with the details