CHANGELOG.md

@@ -9,14 +9,30 @@ project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Breaking
 
-* Fixed `gauge.setToCurrentTime()` to use seconds instead of milliseconds
-  * This conforms to Prometheus [best practices](https://prometheus.io/docs/practices/naming/#base-units)
-* Dropped support for node 4
-
 ### Changed
 
 ### Added
 
+## [11.1.0] - 2018-06-29
+
+* Added ability to set a name prefix in the default metrics
+
+### Changed
+
+* Fixed `startTimer` utility to not mutate objects passed as `startLabels`
+* Fixed `Counter` to validate labels parameter of `inc()` against initial
+  labelset
+* Fixed `AggregatorFactory` losing the aggregator method of metrics
+
+## [11.0.0] - 2018-03-10
+
+### Breaking
+
+* Fixed `gauge.setToCurrentTime()` to use seconds instead of milliseconds
+  * This conforms to Prometheus
+    [best practices](https://prometheus.io/docs/practices/naming/#base-units)
+* Dropped support for node 4
+
 ## [10.2.3] - 2018-02-28
 
 ### Breaking

README.md

@@ -51,10 +51,10 @@ In addition, some Node-specific metrics are included, such as event loop lag,
 active handles and Node.js version. See what metrics there are in
 [lib/metrics](lib/metrics).
 
-`collectDefaultMetrics` takes 1 options object with 2 entries, a timeout for how
-often the probe should be fired and a registry to which metrics should be
-registered. By default probes are launched every 10 seconds, but this can be
-modified like this:
+`collectDefaultMetrics` takes 1 options object with 3 entries, a timeout for how
+often the probe should be fired, an optional prefix for metric names
+and a registry to which metrics should be registered. By default probes are
+launched every 10 seconds, but this can be modified like this:
 
 ```js
 const client = require('prom-client');
@@ -77,6 +77,17 @@ const register = new Registry();
 collectDefaultMetrics({ register });
 ```
 
+To prefix metric names with your own arbitrary string, pass in a `prefix`:
+
+```js
+const client = require('prom-client');
+
+const collectDefaultMetrics = client.collectDefaultMetrics;
+
+// Probe every 5th second.
+collectDefaultMetrics({ prefix: 'my_application_' });
+```
+
 You can get the full list of metrics by inspecting
 `client.collectDefaultMetrics.metricsList`.
 

lib/counter.js

@@ -143,6 +143,9 @@ const inc = function(labels, hash) {
 			throw new Error('It is not possible to decrease a counter');
 		}
 
+		labels = labels || {};
+		validateLabels(this.labelNames, labels);
+
 		const incValue = value === null || value === undefined ? 1 : value;
 
 		this.hashMap = createValue(this.hashMap, incValue, timestamp, labels, hash);

lib/defaultMetrics.js

@@ -58,7 +58,7 @@ module.exports = function startDefaultMetrics(config) {
 			);
 		}
 
-		return defaultMetric(normalizedConfig.register);
+		return defaultMetric(normalizedConfig.register, config);
 	});
 
 	function updateAllMetrics() {

lib/gauge.js

@@ -184,7 +184,7 @@ function startTimer(startLabels) {
 		return endLabels => {
 			const delta = process.hrtime(start);
 			this.set(
-				Object.assign(startLabels || {}, endLabels),
+				Object.assign({}, startLabels, endLabels),
 				delta[0] + delta[1] / 1e9
 			);
 		};

lib/histogram.js

@@ -154,7 +154,7 @@ function startTimer(startLabels) {
 		return endLabels => {
 			const delta = process.hrtime(start);
 			this.observe(
-				Object.assign(startLabels || {}, endLabels),
+				Object.assign({}, startLabels, endLabels),
 				delta[0] + delta[1] / 1e9
 			);
 		};

lib/metricAggregators.js

@@ -14,7 +14,8 @@ function AggregatorFactory(aggregatorFn) {
 			help: metrics[0].help,
 			name: metrics[0].name,
 			type: metrics[0].type,
-			values: []
+			values: [],
+			aggregator: metrics[0].aggregator
 		};
 		// Gather metrics by metricName and labels.
 		const byLabels = new util.Grouper();

lib/metrics/eventLoopLag.js

@@ -12,9 +12,11 @@ function reportEventloopLag(start, gauge) {
 	gauge.set(seconds, Date.now());
 }
 
-module.exports = registry => {
+module.exports = (registry, config = {}) => {
+	const namePrefix = config.prefix ? config.prefix : '';
+
 	const gauge = new Gauge({
-		name: NODEJS_EVENTLOOP_LAG,
+		name: namePrefix + NODEJS_EVENTLOOP_LAG,
 		help: 'Lag of event loop in seconds.',
 		registers: registry ? [registry] : undefined,
 		aggregator: 'average'

lib/metrics/heapSizeAndUsed.js

@@ -7,20 +7,21 @@ const NODEJS_HEAP_SIZE_TOTAL = 'nodejs_heap_size_total_bytes';
 const NODEJS_HEAP_SIZE_USED = 'nodejs_heap_size_used_bytes';
 const NODEJS_EXTERNAL_MEMORY = 'nodejs_external_memory_bytes';
 
-module.exports = registry => {
+module.exports = (registry, config = {}) => {
 	if (typeof process.memoryUsage !== 'function') {
 		return () => {};
 	}
 
 	const registers = registry ? [registry] : undefined;
+	const namePrefix = config.prefix ? config.prefix : '';
 
 	const heapSizeTotal = new Gauge({
-		name: NODEJS_HEAP_SIZE_TOTAL,
+		name: namePrefix + NODEJS_HEAP_SIZE_TOTAL,
 		help: 'Process heap size from node.js in bytes.',
 		registers
 	});
 	const heapSizeUsed = new Gauge({
-		name: NODEJS_HEAP_SIZE_USED,
+		name: namePrefix + NODEJS_HEAP_SIZE_USED,
 		help: 'Process heap size used from node.js in bytes.',
 		registers
 	});
@@ -29,7 +30,7 @@ module.exports = registry => {
 	const usage = safeMemoryUsage();
 	if (usage && usage.external) {
 		externalMemUsed = new Gauge({
-			name: NODEJS_EXTERNAL_MEMORY,
+			name: namePrefix + NODEJS_EXTERNAL_MEMORY,
 			help: 'Nodejs external memory size in bytes.',
 			registers
 		});

lib/metrics/heapSpacesSizeAndUsed.js

@@ -18,7 +18,7 @@ METRICS.forEach(metricType => {
 	NODEJS_HEAP_SIZE[metricType] = `nodejs_heap_space_size_${metricType}_bytes`;
 });
 
-module.exports = registry => {
+module.exports = (registry, config = {}) => {
 	if (
 		typeof v8 === 'undefined' ||
 		typeof v8.getHeapSpaceStatistics !== 'function'
@@ -27,12 +27,13 @@ module.exports = registry => {
 	}
 
 	const registers = registry ? [registry] : undefined;
+	const namePrefix = config.prefix ? config.prefix : '';
 
 	const gauges = {};
 
 	METRICS.forEach(metricType => {
 		gauges[metricType] = new Gauge({
-			name: NODEJS_HEAP_SIZE[metricType],
+			name: namePrefix + NODEJS_HEAP_SIZE[metricType],
 			help: `Process heap space size ${metricType} from node.js in bytes.`,
 			labelNames: ['space'],
 			registers

lib/metrics/osMemoryHeap.js

@@ -6,9 +6,11 @@ const safeMemoryUsage = require('./helpers/safeMemoryUsage');
 
 const PROCESS_RESIDENT_MEMORY = 'process_resident_memory_bytes';
 
-function notLinuxVariant(registry) {
+function notLinuxVariant(registry, config = {}) {
+	const namePrefix = config.prefix ? config.prefix : '';
+
 	const residentMemGauge = new Gauge({
-		name: PROCESS_RESIDENT_MEMORY,
+		name: namePrefix + PROCESS_RESIDENT_MEMORY,
 		help: 'Resident memory size in bytes.',
 		registers: registry ? [registry] : undefined
 	});
@@ -23,10 +25,10 @@ function notLinuxVariant(registry) {
 	};
 }
 
-module.exports = registry =>
+module.exports = (registry, config) =>
 	process.platform === 'linux'
-		? linuxVariant(registry)
-		: notLinuxVariant(registry);
+		? linuxVariant(registry, config)
+		: notLinuxVariant(registry, config);
 
 module.exports.metricNames =
 	process.platform === 'linux'

lib/metrics/osMemoryHeapLinux.js

@@ -31,20 +31,22 @@ function structureOutput(input) {
 	return returnValue;
 }
 
-module.exports = registry => {
+module.exports = (registry, config = {}) => {
 	const registers = registry ? [registry] : undefined;
+	const namePrefix = config.prefix ? config.prefix : '';
+
 	const residentMemGauge = new Gauge({
-		name: PROCESS_RESIDENT_MEMORY,
+		name: namePrefix + PROCESS_RESIDENT_MEMORY,
 		help: 'Resident memory size in bytes.',
 		registers
 	});
 	const virtualMemGauge = new Gauge({
-		name: PROCESS_VIRTUAL_MEMORY,
+		name: namePrefix + PROCESS_VIRTUAL_MEMORY,
 		help: 'Virtual memory size in bytes.',
 		registers
 	});
 	const heapSizeMemGauge = new Gauge({
-		name: PROCESS_HEAP,
+		name: namePrefix + PROCESS_HEAP,
 		help: 'Process heap size in bytes.',
 		registers
 	});

lib/metrics/processCpuTotal.js

@@ -5,26 +5,27 @@ const PROCESS_CPU_USER_SECONDS = 'process_cpu_user_seconds_total';
 const PROCESS_CPU_SYSTEM_SECONDS = 'process_cpu_system_seconds_total';
 const PROCESS_CPU_SECONDS = 'process_cpu_seconds_total';
 
-module.exports = registry => {
+module.exports = (registry, config = {}) => {
 	// Don't do anything if the function doesn't exist (introduced in node@6.1.0)
 	if (typeof process.cpuUsage !== 'function') {
 		return () => {};
 	}
 
 	const registers = registry ? [registry] : undefined;
+	const namePrefix = config.prefix ? config.prefix : '';
 
 	const cpuUserUsageCounter = new Counter({
-		name: PROCESS_CPU_USER_SECONDS,
+		name: namePrefix + PROCESS_CPU_USER_SECONDS,
 		help: 'Total user CPU time spent in seconds.',
 		registers
 	});
 	const cpuSystemUsageCounter = new Counter({
-		name: PROCESS_CPU_SYSTEM_SECONDS,
+		name: namePrefix + PROCESS_CPU_SYSTEM_SECONDS,
 		help: 'Total system CPU time spent in seconds.',
 		registers
 	});
 	const cpuUsageCounter = new Counter({
-		name: PROCESS_CPU_SECONDS,
+		name: namePrefix + PROCESS_CPU_SECONDS,
 		help: 'Total user and system CPU time spent in seconds.',
 		registers
 	});

lib/metrics/processHandles.js

@@ -4,14 +4,16 @@ const Gauge = require('../gauge');
 
 const NODEJS_ACTIVE_HANDLES = 'nodejs_active_handles_total';
 
-module.exports = registry => {
+module.exports = (registry, config = {}) => {
 	// Don't do anything if the function is removed in later nodes (exists in node@6)
 	if (typeof process._getActiveHandles !== 'function') {
 		return () => {};
 	}
 
+	const namePrefix = config.prefix ? config.prefix : '';
+
 	const gauge = new Gauge({
-		name: NODEJS_ACTIVE_HANDLES,
+		name: namePrefix + NODEJS_ACTIVE_HANDLES,
 		help: 'Number of active handles.',
 		registers: registry ? [registry] : undefined
 	});

lib/metrics/processMaxFileDescriptors.js

@@ -5,14 +5,17 @@ const fs = require('fs');
 
 const PROCESS_MAX_FDS = 'process_max_fds';
 
-module.exports = registry => {
+module.exports = (registry, config = {}) => {
 	let isSet = false;
 
 	if (process.platform !== 'linux') {
 		return () => {};
 	}
+
+	const namePrefix = config.prefix ? config.prefix : '';
+
 	const fileDescriptorsGauge = new Gauge({
-		name: PROCESS_MAX_FDS,
+		name: namePrefix + PROCESS_MAX_FDS,
 		help: 'Maximum number of open file descriptors.',
 		registers: registry ? [registry] : undefined
 	});

lib/metrics/processOpenFileDescriptors.js

@@ -5,13 +5,15 @@ const fs = require('fs');
 
 const PROCESS_OPEN_FDS = 'process_open_fds';
 
-module.exports = registry => {
+module.exports = (registry, config) => {
 	if (process.platform !== 'linux') {
 		return () => {};
 	}
 
+	const namePrefix = config.prefix ? config.prefix : '';
+
 	const fileDescriptorsGauge = new Gauge({
-		name: PROCESS_OPEN_FDS,
+		name: namePrefix + PROCESS_OPEN_FDS,
 		help: 'Number of open file descriptors.',
 		registers: registry ? [registry] : undefined
 	});

lib/metrics/processRequests.js

@@ -4,14 +4,16 @@ const Gauge = require('../gauge');
 
 const NODEJS_ACTIVE_REQUESTS = 'nodejs_active_requests_total';
 
-module.exports = registry => {
+module.exports = (registry, config = {}) => {
 	// Don't do anything if the function is removed in later nodes (exists in node@6)
 	if (typeof process._getActiveRequests !== 'function') {
 		return () => {};
 	}
 
+	const namePrefix = config.prefix ? config.prefix : '';
+
 	const gauge = new Gauge({
-		name: NODEJS_ACTIVE_REQUESTS,
+		name: namePrefix + NODEJS_ACTIVE_REQUESTS,
 		help: 'Number of active requests.',
 		registers: registry ? [registry] : undefined
 	});

lib/metrics/processStartTime.js

@@ -5,9 +5,11 @@ const nowInSeconds = Math.round(Date.now() / 1000 - process.uptime());
 
 const PROCESS_START_TIME = 'process_start_time_seconds';
 
-module.exports = registry => {
+module.exports = (registry, config = {}) => {
+	const namePrefix = config.prefix ? config.prefix : '';
+
 	const cpuUserGauge = new Gauge({
-		name: PROCESS_START_TIME,
+		name: namePrefix + PROCESS_START_TIME,
 		help: 'Start time of the process since unix epoch in seconds.',
 		registers: registry ? [registry] : undefined,
 		aggregator: 'omit'

lib/metrics/version.js

@@ -9,9 +9,11 @@ const versionSegments = version
 
 const NODE_VERSION_INFO = 'nodejs_version_info';
 
-module.exports = registry => {
+module.exports = (registry, config = {}) => {
+	const namePrefix = config.prefix ? config.prefix : '';
+
 	const nodeVersionGauge = new Gauge({
-		name: NODE_VERSION_INFO,
+		name: namePrefix + NODE_VERSION_INFO,
 		help: 'Node.js version info.',
 		labelNames: ['version', 'major', 'minor', 'patch'],
 		registers: registry ? [registry] : undefined,

lib/summary.js

@@ -183,7 +183,7 @@ function startTimer(startLabels) {
 		return endLabels => {
 			const delta = process.hrtime(start);
 			this.observe(
-				Object.assign(startLabels || {}, endLabels),
+				Object.assign({}, startLabels, endLabels),
 				delta[0] + delta[1] / 1e9
 			);
 		};

lib/util.js

@@ -86,9 +86,7 @@ exports.printDeprecationObjectConstructor = () => {
 
 exports.printDeprecationCollectDefaultMetricsNumber = timeout => {
 	printDeprecation(
-		`prom-client - A number to defaultMetrics is deprecated, please use \`collectDefaultMetrics({ timeout: ${
-			timeout
-		} })\`.`
+		`prom-client - A number to defaultMetrics is deprecated, please use \`collectDefaultMetrics({ timeout: ${timeout} })\`.`
 	);
 };