couchdb k6 view query with constant arrival

k6_couchdb_constant_arrival_view_query.js

//
// Examples:
//     BENCH_RATE=500 BENCH_DURATION=20s BENCH_VIEW_LIMIT=16 k6 run ./$script.js
//
// config:set("log", "level", "warning").
//


import http from 'k6/http';
import encoding from 'k6/encoding';
import { sleep } from 'k6';
import { randomString } from 'https://jslib.k6.io/k6-utils/1.2.0/index.js';

// Parameters, defaults or from the environment
// Note: environemnt variables are prefixed with "BENCH_"
//

const URL            = env_str('URL', 'http://localhost:15984');
const USER           = env_str('USER', 'adm');
const PASS           = env_str('PASS', 'pass');
const DB             = env_str('DB', 'db');
const DDOC           = env_str('DDOC', 'ddoc')
const VIEW           = env_str('VIEW', 'view')
const VIEW_LIMIT     = env_num('VIEW_LIMIT', 1)
const DURATION       = env_str('DURATION', '5m');
const RATE           = env_num('RATE', 500);
const TAG            = env_str('TAG', '');
const SCENARIOS      = env_str('SCENARIOS', 'view_get');
const XHEADER        = env_str('XHEADER', '');

// Derived params

const DB_URL        = `${URL}/${DB}`;
const VIEW_URL      = `${URL}/${DB}/_design/${DDOC}/_view/${VIEW}`
const INFO_URL      = `${URL}/${DB}/_design/${DDOC}/_info`
const HEADERS       = get_headers(XHEADER, USER, PASS);
const SETUP_PAR     = {'headers': HEADERS, tags: {name: 'setup'}};
const VIEW_PAR      = {'headers': HEADERS, tags: {name: 'view_get'}};

const SCENARIO_DEFAULTS = {
  executor: 'constant-arrival-rate',
  duration: DURATION,
  timeUnit: '1s',
  preAllocatedVUs: 1000,
  maxVUs: 5000
};

// Callbacks & options. These are what k6 expects to call

export const options = {
   scenarios: scenarios(),
   discardResponseBodies: true,
   setupTimeout: '60m',
   // These are bogus, always passing thresholds just so we can
   // see the individual tagged requests times in the summary
   // but in principle these could be turned into a pass/fail test
   thresholds: {
     'http_req_duration{name:view_get}'   : ['p(99)>=0']
   }
};

export function setup() {
  console.log(`
    * tag: ${TAG}
    * scanarios: ${SCENARIOS}
    * url: ${URL}
    * user: ${USER}
    * ddoc: ${DDOC}
    * view: ${VIEW}
    * duration: ${DURATION}
  \n`);
  let res;

  res = http.get(DB_URL, SETUP_PAR);
  if (res.status != 200) {
      throw new Error(`Could not find DB ${DB_URL} ${res.status}`);
  }
  res = http.get(INFO_URL, SETUP_PAR);
  if (res.status != 200) {
      throw new Error(`Could not find view at ${INFO_URL} ${res.status}`);
  }
}

export function view_get () {
  const skey = randomString(10, 'abcdef0123456789');
  http.get(`${VIEW_URL}?start_key="${skey}"&limit=${VIEW_LIMIT}`, VIEW_PAR);
}

/// End of callback functions

// Helpers

function env_str(name, default_val) {
  name = 'BENCH_' + name;
  return __ENV[name] ? __ENV[name] : default_val;
}

function env_num(name, default_val) {
  name = 'BENCH_' + name;
  return __ENV[name] ? Number(__ENV[name]) : default_val;
}

function scenarios() {
  let scenario_keys = SCENARIOS.split(',');
  let scenarios_available = {
    view_get   : {...SCENARIO_DEFAULTS, ...{exec: 'view_get'},   ...{rate: RATE}}
  };
  return Object.fromEntries(scenario_keys.map(k => [k, scenarios_available[k]]));
}

function get_headers(xtra_header, user, pass) {
    let b64 = encoding.b64encode(`${user}:${pass}`);
    let xheader = parse_header(xtra_header);
    return {
        'authorization': `Basic ${b64}`,
        'content-type':'application/json',
        ...xheader
   }
};

function parse_header(header_str) {
  let [name, ...rest] = header_str.split(":");
  let val = rest.join(":");
  return name ? {name : val} : {};
}

Run as:

BENCH_RATE=400 BENCH_DURATION=5m BENCH_VIEW_LIMIT=10 k6 run ./k6_couchdb_constant_arrival_view_query.js 

Views can be created with view_cycle.py

./view_cycle.py -u http://localhost:15984 -a adm:pass -n 1000000 -c0