Creating a custom jaeger plugin to Monitor and troubleshoot complex distributed systems.

As on-the-ground micro-service practitioners are quickly realizing, the majority of operational problems that arise when moving to a distributed architecture are ultimately grounded in two areas: networking and observability. It is simply an orders of magnitude larger problem to network and debug a set of intertwined distributed services versus a single monolithic application.

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Why open tracing?

Jaeger terminology and components

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export function logger(span, event, data) {
span.log({ event: event, value: data })
export function head(request, name) {
let ctx = request.ctx;
return ctx.tracer.startSpan(name, { childOf: ctx.span });
import fastify from 'fastify';
import {Span, Tracer} from 'opentracing';
export default async function(req: fastify.FastifyRequest, res, next){
const ip = req.ips;
let source = req.headers['user-agent'] || ''

if (req.headers['x-ucbrowser-ua']) { //special case of UC Browser
source = req.headers['x-ucbrowser-ua'];
const tracer = req['jaeger']().tracer as Tracer;
const span = req['jaeger']().span as Span;
req['useragent'] = {
ip: ip,
userAgent: source
req['ctx'] = { span, tracer }

How to use it in your service

import jaegerCustomPlugin from './libraries/tracer/jaegerCustomPlugin';
const host = process.env.HOST || (require('../config/url.json')[process.env.NODE_ENV]).host;const scheme = process.env.SCHEME || (require('../config/url.json')[process.env.NODE_ENV]).scheme;const expose = process.env.NODE_ENV === 'production' ? false : true;const configs = (require('../config/url.json')[process.env.NODE_ENV]);app.register(jaegerCustomPlugin, {
serviceName: process.env.PROJECT_NAME,
reporter: {
agentPort: configs.jaeger.port
"jaeger": {
"host": "localhost",
"port": 6832
import {logger, head} from '../../../libraries/tracer/logger';
const createUserSchema: RouteSchema = {
tags: [`${action}`], summary: `Login to app`,
body: Requests.requestBody(userInterface, ['email', 'password']),
}'/auth', { schema: createUserSchema}, async(request, response) => {let span = head(request, 'GATEWAY USER AUTHENTICATION: Login user');
let user;
try {
user = await requestmaker({
service: 'auth',
action: 'user/auth',
method: 'POST',
data: request.body,
ctx: request['ctx']
} catch (ex) {
return response.code(400).send(ex)
logger(span, "login", user);

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I am an experienced back-end software engineer adept in bringing forth expertise in design, installation, testing and maintenance of software systems.

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