Metrics in Detail

N|Solid makes available a rich set of metrics covering the Node.js process's host system, the process itself, the internal behavior of Node.js, and the internal behavior of the V8 JavaScript engine. Combining these data points can give you sophisticated insight into your Node.js deployment.

Many of the key metrics are displayed directly on the N|Solid Console. To make numeric metrics available to your StatsD collector directly from the N|Solid Process, configure using the NSOLID_STATSD environment variable (see the StatsD section for more detail). For the full set of metrics, use the nsolid-cli utility.

Process Information

Property	Description
app	The user-specified application name as set in package.json or the NSOLID_APP environment variable.
appVersion	The user-specified application version as set in package.json.
execPath	The absolute path of the N|Solid executable running the application.
id	The unique N|Solid agent ID. Unique per N|Solid process.
main	The absolute path to the root module in the process's module tree.
nodeEnv	The user-specified NODE_ENV environment variable.
pid	The system process ID for the process.
processStart	The time at which the process started, in seconds.
tags	The user-specified tags as set by the NSOLID_TAGS environment variable.
vulns	The number of known vulnerabilities found in the modules of the process.

System Information

Note: The host system may be actual hardware, a virtual machine, or a container.

Property	Description
arch	The host system's CPU architecture.
cpuCores	The host system's number of CPU cores.
cpuModel	The host system's CPU model.
hostname	The host system's name.
platform	The host system's operating system platform.
totalMem	The host system's total available memory.

System Data

Property	Description
cpuSpeed	The current speed of the host system's CPU (averaged across all cores), in MHz.
freeMem	The host system's amount of free (unused) memory, in bytes.
load1m	The host system's one-minute load average.
load5m	The host system's five-minute load average.
load15m	The host system's fifteen-minute load average.
systemUptime	The host system's uptime, in seconds.

General Process Stats

Property	Description
blockInputOpCount	The total number of block input operations on the process.
blockOutputOpCount	The total number of block output operations on the process.
cpuSystemPercent	The percent CPU used by the process in system calls.
cpuUserPercent	The percent CPU used by the process in user code.
ctxSwitchInvoluntaryCount	The number of involuntary context switches away from the process.
ctxSwitchVoluntaryCount	The number of voluntary context switches away from the process.
cpuPercent	The percent CPU used by the process.
externalMem	The process's memory allocated by Node.js outside of V8's heap, in bytes. This may exceed RSS if large Buffers are soft-allocated by V8.
ipcReceivedCount	The number of IPC messages received by the process.
ipcSentCount	The number of IPC messages sent by the process.
pageFaultHardCount	The number of hard page faults triggered by the process.
pageFaultSoftCount	The number of soft page faults (page reclaims) triggered by the process.
rss	The resident set size (total memory) used by the process, in bytes.
signalCount	The number of signals received by the process.
swapCount	The number of times the process has been swapped out of memory.
title	The current system title of the process.
uptime	The process's uptime, in seconds.
user	The system's user the process is running from.

JavaScript Memory Stats

Note: The memory in "heap" is a subset of the resident set size.

Property	Description
totalAvailableSize	The remaining amount of memory the heap can allocate on the process before hitting the maximum heap size, in bytes.
totalHeapSizeExecutable	The total amount of executable memory allocated in the process's heap, in bytes.
totalPhysicalSize	The amount of physical memory currently committed for the heap of the process, in bytes.
heapSizeLimit	The maximum amount of memory reserved for the heap by the process, as allocated by the host system, in bytes. V8 will terminate with allocation failures if memory is used beyond this.
heapTotal	The process's total allocated JavaScript heap size, in bytes.
heapUsed	The process's total used JavaScript heap size, in bytes.

Node.js Event Loop Stats

Note: To learn more about event loop utilization visit The Event loop utilization blogpost.

Property	Description
loopAvgTasks	The process's average number of async JavaScript entries per event loop cycle.
loopEstimatedLag	The estimated amount of time a I/O response may have to wait in the process, in milliseconds.
loopIdlePercent	The percent time that the process is waiting (idle) for I/O or timers.
loopsPerSecond	The amount of event loop cycles completed in the process, within the last second.
loopTotalCount	The cumulative count of all event loop cycles in the process.

JavaScript Garbage Collection Stats

Property	Description
gcCount	The total number of garbage collections done by the process.
gcCpuPercent	The percent CPU used during garbage collection by the process.
gcDurUs99Ptile	The process's 99th percentile duration of garbage collections, in microseconds.
gcDurUsMedian	The process's median duration of garbage collections, in microseconds.
gcForcedCount	The process's number of externally forced garbage collections.
gcFullCount	The number of garbage collections run by the process which collected all available garbage. Usually only observed when the heapTotal is approaching heapSizeLimit.
gcMajorCount	The number of significant garbage collections done by the process. An example of a "significant" garbage collection is a "Mark-Sweep".

HTTP and DNS Stats

Property	Description
dnsCount	The process's total number of DNS lookups performed.
dnsMedian	The process's median duration of DNS lookups performed, in milliseconds.
httpClientAbortCount	The process's total number of outgoing HTTP(S) client requests canceled due to inactivity.
httpClientCount	The process's total number of outgoing HTTP(S) client requests performed.
httpClientMedian	The process's median duration of outgoing HTTP(S) client requests completed, in milliseconds.
httpClient99Ptile	The process's 99th percentile duration of outgoing HTTP(s) client requests completed, in milliseconds.
httpServerAbortCount	The process's total number of served incoming HTTP(S) requests canceled.
httpServerCount	The process's total number of incoming HTTP(s) requests served.
httpServerMedian	The process's median duration of served incoming HTTP(S) requests completed, in milliseconds.
httpServer99Ptile	The process's 99th percentile duration of served incoming HTTP(S) requests completed, in milliseconds..

Metrics Metadata

Property	Description
time	The ISO8601 timestamp representing when a given metrics window completed.