process-rerun

process-rerun

The purpose of this library is - build simple and flexible interface for parallel command execution with rerun (on fail) possibility

Documents
Usage
Changelog

Documents

buildRunner(buildOpts): returns rerunner: function(string[]): {retriable: string[]; notRetriable: string[]}

arguments	description
buildOpts	Type: object Options for executor
buildOpts.maxThreads	Optional Type: number, How many threads can be executed in same time Default threads count is 5
buildOpts.intime	Optional Type: boolean, if intime is true intime execution approach will be enabled Default is false
buildOpts.shuffle	Optional Type: boolean, Shuffle commands during execution Default threads count is 5
buildOpts.attemptsCount	Optional Type: number, How many times can we try to execute command for success result in next cycle will be executed only faild command, success commands will not be reexecuted Default attempts count is 2
buildOpts.pollTime	Optional Type: number, Period for recheck about free thread Default is 1 second
buildOpts.successExitCode	Optional Type: number, Exit code what will be used for succes process check Default is 0
buildOpts.logLevel	Type: string, one of 'ERROR', 'WARN', 'INFO', 'VERBOSE', 'MUTE' ERROR - only errors, WARN - errors and warnings, INFO - errors, warnings and information, VERBOSE - full logging, MUTE - mute execution output Default is 'ERROR'
buildOpts.currentExecutionVariable	Optional Type: string, will be execution variable with execution index for every cycle will be ++
buildOpts.everyCycleCallback	Optional Type: function, Optional. everyCycleCallback will be executed after cycle, before next execution cycle. Default is false
buildOpts.processResultAnalyzer	Optional Type: function, Optional. processResultAnalyzer is a function where arguments are original command, execution stack trace and notRetriable array processResultAnalyzer should return a new command what will be executed in next cycle or boolean - if satisfactory result
buildOpts.longestProcessTime	Optional Type: number, In case if command execution time is longer than longest Process Time - executor will kill it automatically and will try to execute this command again. Default time is 45 seconds

Usage

const { buildRunner } = require('process-rerun');

async function execCommands() {
  const runner = buildRunner({
    maxThreads: 10, // ten threads
    attemptsCount: 2, // will try to pass all commands two times, one main and one times rerun
    longestProcessTime: 60 * 1000, // if command process execution time is longre than 1 minute will kill it and try to pass in next cycle
    pollTime: 1000, // will check free thread every second
    everyCycleCallback: () => console.log('Cycle done'),
    processResultAnalyzer: (cmd, stackTrace, notRetriableArr) => {
      if (stackTrace.includes('Should be re executed')) {
        return cmd;
      }
      notRetriableArr.push(cmd);
    }, //true - command will be reexecuted
  });
  const result = await runner([
    `node -e 'console.log("Success first")'`,
    `node -e 'console.log("Success second")'`,
    `node -e 'console.log("Failed first"); process.exit(1)'`,
    `node -e 'console.log("Success third")'`,
    `node -e 'console.log("Failed second"); process.exit(1)'`,
  ]);

  console.log(result);
  /*
  {
    retriable: [
      `node -e 'console.log("Failed first"); process.exit(1)' --opt1=opt1value --opt1=opt1value`,
      `node -e 'console.log("Failed second"); process.exit(1)' --opt1=opt1value --opt1=opt1value`
    ],
    notRetriable: []
  }
  */
}

intime approach vs circle approach

circle approach

five processes execution, two execution attempts, five parallel execution

first execution attempt (three failed)	second execution attempt (one failed)	third execution attempt (o failed)
1 p1 --------------------------> success	p2 ---> success	p4 -----------> success
2 p2 ---> fail	p4 -----------> fail
3 p3 -------> fail	p3 -------> success
4 p4 -----------> fail
5 p5 -----> success

Full execution time:
p1 (first attempt) --------------------------> + p4 (second attempt) -----------> + (third attempt) p4 ----------->

intime approach (with same fail scheme)

every process has attemp count timer

f - fail
s - success
1 p1 -------------------------->s
2 p2 --->f--->s
3 p3 ------->f------->s
4 p4 ----------->f
5 p5 ----->s(p4)----------->f----------->s

Full execution time:

5 p5 ----->s(p4)----------->f----------->s

Failed process will check that free parallel exists and start execution when free parallel will be found.

Changelog

Version 0.1.11