swagger-stats | API Observability

https://swaggerstats.io | Guide

Trace API calls and Monitor API performance, health and usage statistics in Node.js Microservices

Express, Fastify, Koa, Hapi, Restify

swagger-stats traces REST API requests and responses in Node.js Microservices, and collects statistics per API Operation. swagger-stats detects API operations based on express routes. You may also provide Swagger (Open API) specification, and swagger-stats will match API requests with API Operations defined in swagger specification.

swagger-stats exposes statistics and metrics per API Operation, such as GET /myapi/:parameter, or GET /pet/{petId}

Built-In API Telemetry

swagger-stats provides built-in Telemetry UX, so you may enable swagger-stats in your app, and start monitoring immediately, with no infrastructure requirements. Navigate to http://<your app host:port>/swagger-stats/

API Analytics with Elasticsearch and Kibana

swagger-stats stores details about each request/response in Elasticsearch, so you may use Kibana to perform detailed analysis of API usage over time, build visualizations and dashboards

See dashboards/elastic6 for swagger-stats Kibana visualizations and dashboards

Monitoring and Alerting with Prometheus and Grafana

swagger-stats exposes metrics in Prometheus format, so you may use Prometheus and Grafana to setup API monitoring and alerting

See dashboards/prometheus for swagger-stats Grafana dashboards

With statistics and metrics exposed by swagger-stats you may spot problematic API endpoints, see where most of errors happens, catch long-running requests, analyze details of last errors, observe trends, setup alerting.

swagger-stats provides:

Metrics in Prometheus format, so you may use Prometheus and Grafana to setup API monitoring and alerting
Storing details about each API Request/Response in Elasticsearch, so you may use Kibana to perform analysis of API usage over time, build visualizations and dashboards
Built-in API Telemetry UI, so you may enable swagger-stats in your app, and start monitoring right away, with no additional tools required
Exposing collected statistics via API, including:
Counts of requests and responses(total and by response class), processing time (total/avg/max), content length(total/avg/max) for requests and responses, rates for requests and errors. This is baseline set of stats.
Statistics by Request Method: baseline stats collected for each request method
Timeline: baseline stats collected for each 1 minute interval during last 60 minutes. Timeline helps you to analyze trends.
Errors: count of responses per each error code, top "not found" resources, top "server error" resources
Last errors: request and response details for the last 100 errors (last 100 error responses)
Longest requests: request and response details for top 100 requests that took longest time to process (time to send response)
Tracing: Request and Response details - method, URLs, parameters, request and response headers, addresses, start/stop times and processing duration, matched API Operation info
API Statistics: baseline stats and parameter stats per each API Operation. API operation detected based on express routes, and based on Swagger (Open API) specification
CPU and Memory Usage of Node process

How to Use

Install

npm install swagger-stats --save

If you haven't added prom-client already, you should do this now. It's a peer dependency of swagger-stats as of version 0.95.19.

npm install prom-client@12 --save

Enable swagger-stats middleware in your app

Express

const swStats = require('swagger-stats');
const apiSpec = require('swagger.json');
app.use(swStats.getMiddleware({swaggerSpec:apiSpec}));

Fastify

const swStats = require('swagger-stats');
const apiSpec = require('swagger.json');

const fastify = require('fastify')({
    logger: true
});

// Enable swagger-stats
fastify.register(require('fastify-express')).then(()=>{
    fastify.register(swStats.getFastifyPlugin, {swaggerSpec:apiSpec});
});

Koa

express-to-koa can be used which is just a simple Promise wrapper.

const swStats = require('swagger-stats');
const apiSpec = require('swagger.json');
const e2k = require('express-to-koa');
app.use(e2k(swStats.getMiddleware({ swaggerSpec:apiSpec })));

Hapi

const swStats = require('swagger-stats');
const swaggerSpec = require('./petstore.json');

const init = async () => {

    server = Hapi.server({
        port: 3040,
        host: 'localhost'
    });

    await server.register({
        plugin: swStats.getHapiPlugin,
        options: {
             swaggerSpec:swaggerSpec
        }
    });

    await server.start();
    console.log('Server running on %s', server.info.uri);
};

Restify

const restify = require('restify');
const swStats = require('swagger-stats');
const apiSpec = require('swagger.json');

const server = restify.createServer();

server.pre(swStats.getMiddleware({
    swaggerSpec:apiSpec,
}));

See /examples for sample apps

Get Statistics with API

$ curl http://<your app host:port>/swagger-stats/stats
{
  "startts": 1501647865959,
  "all": {
    "requests": 7,
    "responses": 7,
    "errors": 3,
    "info": 0,
    "success": 3,
    "redirect": 1,
    "client_error": 2,
    "server_error": 1,
    "total_time": 510,
    "max_time": 502,
    "avg_time": 72.85714285714286,
    "total_req_clength": 0,
    "max_req_clength": 0,
    "avg_req_clength": 0,
    "total_res_clength": 692,
    "max_res_clength": 510,
    "avg_res_clength": 98,
    "req_rate": 1.0734549915657108,
    "err_rate": 0.4600521392424475
  },
  "sys": {
    "rss": 59768832,
    "heapTotal": 36700160,
    "heapUsed": 20081776,
    "external": 5291923,
    "cpu": 0
  },
  "name": "swagger-stats-testapp",
  "version": "0.90.1",
  "hostname": "hostname",
  "ip": "127.0.0.1"
}

Take a look at Documentation for more details on API and returned statistics.

Get Prometheus Metrics

$ curl http://<your app host:port>/swagger-stats/metrics
# HELP api_all_request_total The total number of all API requests received
# TYPE api_all_request_total counter
api_all_request_total 88715
# HELP api_all_success_total The total number of all API requests with success response
# TYPE api_all_success_total counter
api_all_success_total 49051
# HELP api_all_errors_total The total number of all API requests with error response
# TYPE api_all_errors_total counter
api_all_errors_total 32152
# HELP api_all_client_error_total The total number of all API requests with client error response
# TYPE api_all_client_error_total counter
api_all_client_error_total 22986

. . . . . . . . . .

Default Metrics

To collect prom-client default metrics:

const swaggerStats = require('swagger-stats');
const promClient = require('prom-client');

promClient.collectDefaultMetrics();

Some Node.js specific metrics are included, such as event loop lag:

# HELP nodejs_eventloop_lag_seconds Lag of event loop in seconds.
# TYPE nodejs_eventloop_lag_seconds gauge
nodejs_eventloop_lag_seconds 0.000193641 1597303877464

. . . . . . . . . .

Updates

See Changelog

Enhancements and Bug Reports

If you find a bug, or have an enhancement in mind please post issues on GitHub.

License

MIT

Manhydra/swagger-stats