2a:null 2b:["$","title",null,{"children":"AWS EC2 Spot Instance Simulator | Rusty Conover | Observable"}] 30:T46c,md`# AWS EC2 Spot Instance Simulator

AWS EC2 Spot instances are a way to save money by offering the opportunity to purchase "spare" EC2 instances from AWS. The catch is [AWS EC2 Spot instances](https://aws.amazon.com/ec2/spot/) are able to be terminated at any time. Using the [AWS Spot Instance Advisor](https://aws.amazon.com/ec2/spot/instance-advisor/) you can see the applicable termination rate over the past month. When you have a long-running task you should simulate the likelihood of having that task complete successfully if the task is not robust to being interrupted and resuming where it left off. By building a simulation that allows various parameters to be changed a better understanding of when to use on-demand EC2 instances versus spot instances can be formed. #### Assumptions: 1. It is not clear what the time interval is between possible interruptions. This model assumes a uniform but adjustable time between being possibly interrupted. 2. Instances will be terminated as soon as the task they are working on is complete. `31:T1110,// Simulate the execution of a single task for a fixed amount of time. simulateTaskRun = ( remainingTaskTimeSeconds, useCheckpoints = false, resumeFromCheckpoint = false, terminateAfterCheckpoint = false, useSpotBlocks = false ) => { var intervalCount = 0; // How many termination intervals need to be passed before this task run is fully complete. // 1. This needs to include the time spent restoring the checkpoints // 2. Include the time spent writing checkpoints as necessary. var neededIntervals; var fullRunTimeSeconds = remainingTaskTimeSeconds + instanceStartupSeconds; if (useCheckpoints) { // If we are restoring, add the time to restore the checkpoint. fullRunTimeSeconds = resumeFromCheckpoint ? checkpointRestoreSeconds : 0; fullRunTimeSeconds += instanceStartupSeconds; if (terminateAfterCheckpoint) { if (remainingTaskTimeSeconds < checkpointSeconds) { // Not enough time for a single checkpoint. fullRunTimeSeconds += remainingTaskTimeSeconds; } else { fullRunTimeSeconds += checkpointSeconds + checkpointSaveSeconds; } } else { const numberOfSavedCheckpoints = Math.floor( remainingTaskTimeSeconds / checkpointSeconds ); fullRunTimeSeconds += numberOfSavedCheckpoints * checkpointSaveSeconds; fullRunTimeSeconds += remainingTaskTimeSeconds; } } neededIntervals = Math.ceil(fullRunTimeSeconds / intervalDuration); if (useSpotBlocks) { // Ignore the possibility of being terminated by AWS // becase the spot block has been purchased with the duration. intervalCount = Math.ceil( Math.min(fullRunTimeSeconds, spotBlockDurationHours * 3600) / intervalDuration ); } else { // Perform the actual simulation of task through the // termination intervals. do { intervalCount++; } while ( Math.random() < 1 - probabilityOfTermination && intervalCount < neededIntervals ); } const taskExecutionSeconds = intervalCount * intervalDuration; var billedSeconds; const completed = intervalCount >= neededIntervals; if (completed) { // This task completed the entire that it desired to run and // was not terminated by AWS, so the entire running time is // billed. // The time that the task run needs to include both full execution time // the time to restore from a snapshot if applicable // plus the time to save incremental snapshots along the way. billedSeconds = fullRunTimeSeconds; } else { if (taskExecutionSeconds <= 3600) { // This condition occurrs if the task was terminated by AWS, // if it is terminated in the first hour the time is not billed. billedSeconds = 0; } else { billedSeconds = taskExecutionSeconds; } } // How much work was actually performed on the task outside of // snapshots and saving checkpoints? This is necessary to track // progress towards the completion of the task. var taskProgressSeconds = Math.max( taskExecutionSeconds - instanceStartupSeconds, 0 ); if (useCheckpoints) { if (resumeFromCheckpoint) { taskProgressSeconds -= checkpointRestoreSeconds; } // Remove all of time spent saving checkpoints, this // cannot be simple division since the time to save the checkpoint should // be removed from task execution time. let r = taskProgressSeconds; while (r >= checkpointSeconds) { taskProgressSeconds -= checkpointSaveSeconds; r -= checkpointSeconds + checkpointSaveSeconds; } // Make sure there never was negative progress. taskProgressSeconds = Math.max(0, taskProgressSeconds); if (completed) { // Since the interval may have run longer than the task // terminate it there. taskProgressSeconds = Math.min( remainingTaskTimeSeconds, taskProgressSeconds ); } } return { //rawRemainingTaskTimeSeconds: remainingTaskTimeSeconds, //rawUseCheckpoints: useCheckpoints, //rawResumeFromCheckpoint: resumeFromCheckpoint, //rawTerminateAfterCheckpoint: terminateAfterCheckpoint, completed, billedSeconds, freeSeconds: completed ? 0 : (intervalCount * intervalDuration) % 3600, taskProgressSeconds, wallClockSeconds: completed ? fullRunTimeSeconds : taskExecutionSeconds }; }32:T10ae,// Simulate the collection of tasks that are run. taskSimulations = (useCheckpoints = false, useSpotBlocks = false) => { var totalBilledSeconds = 0; var freeTerminationSeconds = 0; var completed = 0; var attempts = 0; var wallClockSeconds = []; var allRunResults = []; var attemptWallClockSeconds = 0; var writtenCheckpoints = 0; var startTaskSeconds; var totalTaskLengthSeconds = 0; var remainingTaskSeconds = taskLengthSecondsGen(); startTaskSeconds = remainingTaskSeconds; // You may want to increase the upper limit here to simulate more tasks // but the more time spent simulating slows down the main refresh loop. // in the future look into web workers. for (var j = 0; j < groupTaskSimulationCount; j++) { // I need to ensure that I get n samples > the task interval then add up all of the time // that it took to get them and charge them by the hour. var result; if (useCheckpoints) { // Limit the number of retries for checkpoints. var checkpointRetries = maxCheckpointRetries; const runResults = []; do { // Is this task run being restored from a checkpoint? const restoreFromCheckpoint = useCheckpoints && remainingTaskSeconds !== startTaskSeconds; result = simulateTaskRun( // Run either until the next checkpoint time if terminate after each checkpoint // or attempt to run to the completion of the task. remainingTaskSeconds, useCheckpoints, restoreFromCheckpoint, terminateAfterCheckpoint, useSpotBlocks ); attempts++; if (result.taskProgressSeconds > remainingTaskSeconds) { console.log( `Task ran for too long ${result.taskProgressSeconds - remainingTaskSeconds} interval ${intervalDuration}`, `Max run seconds ${remainingTaskSeconds} ran for progress=${result.taskProgressSeconds}`, `Use checkpoints: ${useCheckpoints} restore from ckpt: ${restoreFromCheckpoint}`, result ); } runResults.push(result); if (result.completed) { remainingTaskSeconds -= result.taskProgressSeconds; } else { // Remove all of the time that has been checkpointed but don't count // any time that wasn't saved by checkpoints. remainingTaskSeconds -= Math.floor(result.taskProgressSeconds / (checkpointMinutes * 60)) * (checkpointMinutes * 60); } attemptWallClockSeconds += result.wallClockSeconds; totalBilledSeconds += result.billedSeconds; freeTerminationSeconds += result.freeSeconds; if (remainingTaskSeconds === 0) { completed++; totalTaskLengthSeconds += startTaskSeconds; allRunResults.push(runResults); wallClockSeconds.push(attemptWallClockSeconds); attemptWallClockSeconds = 0; break; } else { // we still have time pending. writtenCheckpoints += Math.floor( result.executedSeconds / (checkpointMinutes * 60) ); } } while (checkpointRetries-- >= 0); startTaskSeconds = remainingTaskSeconds = taskLengthSecondsGen(); } else { result = simulateTaskRun( remainingTaskSeconds, false, false, false, useSpotBlocks ); attempts++; attemptWallClockSeconds += result.wallClockSeconds; totalBilledSeconds += result.billedSeconds; freeTerminationSeconds += result.freeSeconds; if (result.completed) { completed++; totalTaskLengthSeconds += startTaskSeconds; wallClockSeconds.push(attemptWallClockSeconds); attemptWallClockSeconds = 0; startTaskSeconds = remainingTaskSeconds = taskLengthSecondsGen(); } } if (completed >= numberOfTasks) { break; } } return { attempts, maxWallClockSeconds: Math.max(...wallClockSeconds), wallClockSeconds, allRunResults, totalTaskLengthSeconds, writtenCheckpoints, wasAbleToFill: completed >= numberOfTasks, billedSeconds: totalBilledSeconds, freeTerminationSeconds: freeTerminationSeconds }; }33:Te0e,simulationStatsReport = ( title, summaryStats, checkpointStats, reportBlocks ) => { const currencyFormat = d3.format("$,.2f"); const integerFormat = d3.format(",.0f"); const percentFormat = d3.format(".2%"); const intervalFormat = s => { return integerFormat(s); }; const sources = [summaryStats, checkpointStats].filter(d => d != null); const e = (func, format) => { if (sources.length === 1) { return ( sources .map(func) .map(format) .join("|") + "|" ); } else { const d = sources.map(func); d.push(d[1] - d[0]); return d.map(format).join("|") + "|"; } }; const tableHeader = `| | ${ checkpointStats ? "Without Checkpoints | With Checkpoints | Change " : "Value " } | |---| ${checkpointStats ? "--:|--:|--:|" : "--:"} |`; return md`----- ## ${title} ${ reportBlocks ? "" : summaryStats.totalTaskLengthSeconds.mean * (costPerHourCPUOnDemand / 3600) - summaryStats.billedSeconds.mean * (costPerHourCPU / 3600) > 0 ? "It is cost efficient to use spot instances to run the tasks." : "It is cost efficient to use on-demand instances to run the tasks." } ${tableHeader} | Total CPU Time needed for tasks using on-demand (seconds) | ${e( d => summaryStats.totalTaskLengthSeconds.mean, intervalFormat )} | Simulated average billed CPU seconds to complete all tasks using spot instances (seconds) | ${e( d => d.billedSeconds.mean, intervalFormat )} | Billed CPU second overhead multiplier (1.0 is equal to on-demand instances) | ${e( d => d.billedSeconds.mean / summaryStats.totalTaskLengthSeconds.mean, d3.format(".2f") )}
### Wall Clock Time ${tableHeader} | Wall Clock Time needed execute all tasks using on-demand (seconds) | ${e( d => summaryStats.totalTaskLengthSeconds.mean, integerFormat )} | Simulated average wall clock to complete all tasks (seconds) | ${e( d => d.maxWallClockSeconds.mean * numberOfTasks, integerFormat )}
### Cost On Demand ${tableHeader} | On demand CPU cost to complete all tasks (dollars) | ${e( d => summaryStats.totalTaskLengthSeconds.mean * (costPerHourCPUOnDemand / 3600), currencyFormat )}
### Using Spot Pricing ${reportBlocks ? " with Spot Blocks" : ""} ${tableHeader} | Average simulated cost to complete all tasks (dollars) | ${e( d => d.billedSeconds.mean * ((reportBlocks ? spotBlockPrice : costPerHourCPU) / 3600), currencyFormat )} | Standard deviation Simulated cost to complete all tasks (dollars) | ${e( d => d.billedSeconds.sd * ((reportBlocks ? spotBlockPrice : costPerHourCPU) / 3600), currencyFormat )}
### Savings ${tableHeader} | Average simulated savings from using spot pricing vs on-demand pricing (dollars) | ${e( d => summaryStats.totalTaskLengthSeconds.mean * (costPerHourCPUOnDemand / 3600) - d.billedSeconds.mean * (costPerHourCPU / 3600), currencyFormat )} | Simulated % discount compared to on-demand pricing | ${e( d => (summaryStats.totalTaskLengthSeconds.mean * (costPerHourCPUOnDemand / 3600) - d.billedSeconds.mean * ((reportBlocks ? spotBlockPrice : costPerHourCPU) / 3600)) / (summaryStats.totalTaskLengthSeconds.mean * (costPerHourCPUOnDemand / 3600)), percentFormat )}
`; }34:T74c,chart2 = function(xmin, xmax, data, height, xlabel, ylabel, chartTitle) { let usedBins = histogramBinCount; if (xmax == xmin) { return md`No histogram available as all samples are a single value: ${xmax}`; } const svg = d3.select(DOM.svg(width, height)); const x = d3 .scaleLinear() .domain([xmin, xmax]) .nice() //.domain(d3.extent(data)).nice() .range([margin.left, width - margin.right]); const xAxis = g => g .attr("transform", `translate(0,${height - margin.bottom})`) .call(d3.axisBottom(x).tickSizeOuter(0)) .call(g => g .append("text") .attr("x", width - margin.right) .attr("y", 30) .attr("fill", "#000") .attr("font-weight", "bold") .attr("text-anchor", "end") .text(xlabel) ); const yAxis = g => g .attr("transform", `translate(${margin.left},0)`) .call(d3.axisLeft(y)) .call(g => g.select(".domain").remove()) .call(g => g .select(".tick:last-of-type text") .clone() .attr("x", 4) .attr("text-anchor", "start") .attr("font-weight", "bold") .text(ylabel) ); const bins = d3 .histogram() .domain(x.domain()) .thresholds(x.ticks(usedBins))(data); const y = d3 .scaleLinear() .domain([0, d3.max(bins, d => d.length)]) .nice() .range([height - margin.bottom, margin.top]); const bar = svg .append("g") .text(chartTitle) .attr("fill", "purple") .selectAll("rect") .data(bins) .join("rect") .attr("x", d => x(d.x0) + 1) .attr("width", d => Math.max(0, x(d.x1) - x(d.x0) - 1)) .attr("y", d => y(d.length)) .attr("height", d => y(0) - y(d.length)); svg.append("g").call(xAxis); svg.append("g").call(yAxis); x; return svg.node(); }35:[] 2e:{"id":"7e823a47c90a2d8e","slug":"aws-ec2-spot-instance-simulator","title":"AWS EC2 Spot Instance Simulator","thumbnail":"4d702c37016935c4b53805052799ddd4b43935a55ceed51f9663f0d7293589db","access_level":"public","create_time":"$D2019-12-14T04:03:32.165Z","update_time":"$D2019-12-18T18:31:33.184Z","view_time":null,"first_public_time":"$D2019-12-15T00:43:35.915Z","fork":false,"stars":3,"starred":false,"owner":{"type":"team","id":"7086dbb1b7698f76","login":"rustyconover","name":"Rusty Conover","avatar_url":"https://avatars-next.observableusercontent.com/019e8b78c476a383690d3ab8df8e09fc99d70a5c22a53b885784dcbcc294535c","tier":"starter_2024"},"version":1353,"publish_version":1353,"role":null,"authored":false,"authors":[{"type":"individual","id":"cf2241b0768bf813","login":"rustyconover","name":"Rusty Conover","avatar_url":"https://avatars-next.observableusercontent.com/019e8b78c476a383690d3ab8df8e09fc99d70a5c22a53b885784dcbcc294535c","tier":null}],"members":[{"type":"individual","id":"cf2241b0768bf813","login":"rustyconover","name":"Rusty Conover","avatar_url":"https://avatars-next.observableusercontent.com/019e8b78c476a383690d3ab8df8e09fc99d70a5c22a53b885784dcbcc294535c","tier":null,"role":"editor"}],"comments":[],"custom_thumbnail":false,"trashed":false,"subscribed":null,"forks":1,"collection":null,"type":"notebook","body":{"title":"AWS EC2 Spot Instance Simulator","cells":[{"id":0,"value":"$30","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":102,"value":"md`## Simulation Parameters`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":14,"value":"viewof taskLengthMinutesBase = slider({\n min: 1,\n max: 60 * 8,\n step: 1,\n value: 175,\n title: \"Base task execution time in minutes:\",\n description: \"How long the task takes to finish once started.\"\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":1107,"value":"md`You can draw the task length from a distribution if you like by customizing the function below:`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":1036,"value":"function taskLengthMinutes() {\n // Determine how long the task should actually take\n // it may be useful to sample from a statistical distribution\n // or add random noise rather than assuming all tasks take a\n // fixed amount of time to execute.\n\n // The function is not stateful and will be sampled repeatedly.\n\n // For example this will make tasks take + or - 5% of the base time.\n //return (\n // taskLengthMinutesBase +\n // (Math.random() > 0.5 ? 1 : -1) * taskLengthMinutesBase * 0.05\n //);\n\n // For now just use the specified time.\n return taskLengthMinutesBase;\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":5,"value":"viewof probabilityOfTermination = slider({\n min: 0.001,\n max: 0.25,\n step: 0.001,\n precision: 3,\n format: \".1%\",\n value: 0.025,\n title: \"Probability of termination:\",\n description:\n \"The probability that the instance will be terminated in the next termination interval. This is disclosed at the AWS EC2 Spot Advisor.\"\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":8,"value":"viewof intervalDuration = slider({\n min: 1,\n max: 240,\n step: 1,\n value: 120,\n title:\n \"Duration of interval between possible termination selection (seconds):\",\n description: \"The interval in seconds between possible termination events\"\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":12,"value":"viewof numberOfSamples = slider({\n min: 1,\n max: 50000,\n step: 1,\n value: 10000,\n title: \"Number of simulations:\",\n description: \"The number of simulations to perform.\"\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":1140,"value":"viewof instanceStartupMinutes = slider({\n min: 0,\n max: 60,\n step: 1,\n value: 4,\n title:\n \"Minutes needed for instance to complete initializing and become ready to run the task:\",\n description:\n \"What is the time between booting the instance and when it starts processing wor?.\"\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":533,"value":"md`-----`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":505,"value":"md`## Histogram of Simulated Task Execution Lifespans in Minutes`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":44,"value":"chart = {\n const svg = d3.create(\"svg\").attr(\"viewBox\", [0, 0, width, height]);\n\n svg\n .append(\"g\")\n .selectAll(\"rect\")\n .data(bins)\n .join(\"rect\")\n .attr(\"fill\", d => {\n // FIXME this should be sampled.\n if (d.x1 <= simpleTaskCutoffSeconds) {\n return \"tomato\";\n }\n return \"limegreen\";\n })\n .attr(\"x\", d => x(d.x0) + 1)\n .attr(\"width\", d => Math.max(0, x(d.x1) - x(d.x0) - 1))\n .attr(\"y\", d => y(d.length))\n .attr(\"height\", d => y(0) - y(d.length));\n\n svg.append(\"g\").call(xAxis);\n\n svg.append(\"g\").call(yAxis);\n\n return svg.node();\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":537,"value":"md`## Summary Results for Single Task`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":111,"value":"md`\n\n| | |\n|---|---:|\n| Percentage of simulations completed successfully: | ${d3.format(\".2%\")(\n simulationsCompletedSuccessfully / numberOfSamples\n)} |\n| Percentage of simulations failed: | ${d3.format(\".2%\")(\n (numberOfSamples - simulationsCompletedSuccessfully) / numberOfSamples\n)} |\n`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":548,"value":"md`-----`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":195,"value":"md`## Simulating a Collection of Parallel Tasks\n\n### Scenario:\n\nRun a collection of parallel tasks on different instances and the overall task is not complete until all tasks have been successfully processed. The individual tasks are not able to be checkpointed and resumed and will be restarted as necessary.\n\n1. How much will it cost to run the collection of tasks? \n - Is it cost effective to use spot instances compared to on-demand?\n2. What is an estimated wall clock completion time for the collection of tasks? \n\n#### Assumptions: \n1. AWS Spot instances are not billed if they are interrupted by AWS for the for the [first hour of time](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/spot-interruptions.html). \n`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":556,"value":"md`## Simulation Parameters\n\nThe previous parameters are also used in this simulation.\n\n${\n !isFinite(simStats.normal.billedSeconds.mean)\n ? \"

The multiple task simulation is not able to be performed under these simulation conditions.

The likelyhood of a single task being successfully completed statistically too low.

Adjust your simulation parameters to increase successful single task execution.

\"\n : \"\"\n}\n`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":202,"value":"viewof numberOfTasks = slider({\n min: 1,\n max: 100,\n step: 1,\n value: 5,\n title: \"Number of tasks that need to sucessfully complete:\"\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":204,"value":"viewof costPerHourCPU = slider({\n min: 0.01,\n max: 10,\n step: 0.01,\n value: 0.68,\n title: \"Cost per hour of CPU time (spot price bid amount):\"\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":1343,"value":"md`You likely want to look at [spot prices](https://aws.amazon.com/ec2/spot/pricing/) on the AWS website.`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":409,"value":"viewof costPerHourCPUOnDemand = slider({\n min: 0.01,\n max: 10,\n step: 0.01,\n value: 2.66,\n title: \"Cost per hour of CPU time (on-demand cost):\"\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":1348,"value":"md`You likely want to look at [on-demand prices](https://aws.amazon.com/ec2/pricing/on-demand/) on the AWS website.`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":715,"value":"simulationStatsReport(\"Parallel Task Simulation Results\", simStats.normal)","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":329,"value":"md`### Histogram of Simulated Maximum Wall Clock Time for Completion of All ${numberOfTasks} Tasks`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":291,"value":"chart2(\n Math.min(...fullTaskSimulations.map(r => r.maxWallClockSeconds)),\n Math.max(...fullTaskSimulations.map(r => r.maxWallClockSeconds)),\n fullTaskSimulations.map(r => r.maxWallClockSeconds),\n 300,\n \"Wall Clock Seconds\",\n \"Occurrances\",\n)","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":462,"value":"md`### Histogram of Simulated Wall Clock Time To Complete Single Tasks`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":449,"value":"{\n const d = [];\n fullTaskSimulations.map(r => r.wallClockSeconds.map(t => d.push(t)));\n return chart2(\n Math.min(...d),\n Math.max(...d),\n d,\n 300,\n \"Wall Clock Seconds\",\n \"Occurrances\"\n );\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":398,"value":"md`### Histogram of Simulated Cost for Completion of All ${numberOfTasks} Tasks`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":388,"value":"{\n const d2 = fullTaskSimulations.map(\n r => (r.billedSeconds * costPerHourCPU) / 60 / 100\n );\n return chart2(\n Math.min(...d2),\n Math.max(...d2),\n d2,\n 300,\n \"Dollars\",\n \"Occurrances\"\n );\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":475,"value":"md`### Histogram of Simulated Number of Retry Attempts To Complete ${numberOfTasks} Tasks`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":470,"value":"{\n const d = fullTaskSimulations.map(r => r.attempts - numberOfTasks);\n return chart2(\n Math.min(...d),\n Math.max(...d),\n d,\n 300,\n \"Task Retry Count\",\n \"Occurrances\"\n );\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":350,"value":"viewof histogramBinCount = slider({\n min: 1,\n max: 200,\n step: 5,\n value: 50,\n title: \"Number of histogram bins:\",\n description: \"Determine the coarseness of the histograms\"\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":645,"value":"md`## Simulating a Collection of Parallel Tasks with Checkpointing\n\nScenerio: Instead of tasks needing to execute from beginning to end to be completed, tasks have the ability to save their progress after a fixed interval of time and resume from that point. \n\n### Questions\n\n1. How often should work be checkpointed?\n2. Should tasks run all the way through to completion if they are not interrupted by AWS? \n`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":897,"value":"md`## Simulation Parameters\n\nThe previous parameters are also used in this simulation.\n\n${\n !isFinite(simStats.normal.billedSeconds.mean)\n ? \"

\"\n : \"\"\n}\n`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":650,"value":"viewof checkpointMinutes = slider({\n min: Math.min(checkpointRestoreMinutes + 1, checkpointSaveMinutes + 1),\n max: taskLengthMinutes(),\n step: 1,\n value: 55,\n title: \"Minutes between checkpoints:\"\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":657,"value":"viewof terminateAfterCheckpoint = checkbox({\n description: \"Terminate the instance after each checkpoint\",\n options: [{ value: \"T\", label: \"Yes\" }],\n value: \"\"\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":911,"value":"viewof checkpointSaveMinutes = slider({\n min: 0,\n max: taskLengthMinutes,\n step: 1,\n value: 3,\n title: \"Number of minutes needed to save a checkpoint:\"\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":914,"value":"viewof checkpointRestoreMinutes = slider({\n min: 0,\n max: taskLengthMinutes,\n step: 1,\n value: 5,\n title: \"Number of minutes needed to load and restore a checkpoint:\"\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":726,"value":"simulationStatsReport(\n \"Parallel Task Simulation Results With Checkpoints\",\n simStats.normal,\n simStats.normalCheckpoints\n)","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":859,"value":"md`### Histogram of Simulated Maximum Wall Clock Time for Completion of All ${numberOfTasks} Tasks With Checkpoints`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":856,"value":"{\n const d = fullTaskSimulationsWithCheckpoints.map(r => r.maxWallClockSeconds);\n return chart2(\n Math.min(...d),\n Math.max(...d),\n d,\n 300,\n \"Wall Clock Seconds\",\n \"Occurrances\"\n );\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":865,"value":"md`### Histogram of Simulated Wall Clock Time To Complete Single Tasks With Checkpoints`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":867,"value":"{\n const d = [];\n fullTaskSimulationsWithCheckpoints.map(r =>\n r.wallClockSeconds.map(t => d.push(t))\n );\n return chart2(\n Math.min(...d),\n Math.max(...d),\n d,\n 300,\n \"Wall Clock Seconds\",\n \"Occurrances\"\n );\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":873,"value":"md`### Histogram of Simulated Cost for Completion of All ${numberOfTasks} Tasks With Checkpoints`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":876,"value":"{\n const d2 = fullTaskSimulationsWithCheckpoints.map(\n r => (r.billedSeconds * costPerHourCPU) / 60 / 100\n );\n return chart2(\n Math.min(...d2),\n Math.max(...d2),\n d2,\n 300,\n \"Dollars\",\n \"Occurrances\"\n );\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":879,"value":"md`### Histogram of Simulated Number of Retry Attempts To Complete ${numberOfTasks} Tasks With Checkpoints`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":881,"value":"{\n const d = fullTaskSimulationsWithCheckpoints.map(\n r => r.attempts - numberOfTasks\n );\n return chart2(\n Math.min(...d),\n Math.max(...d),\n d,\n 300,\n \"Task Retry Count\",\n \"Occurrances\"\n );\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":1148,"value":"md`## EC2 Spot Blocks\n\n[EC2 Spot blocks](https://aws.amazon.com/blogs/aws/new-ec2-spot-blocks-for-defined-duration-workloads/) are EC2 instances with the guarantee they will not be interrupted for the purchased duration of time. The duration of time they can be purchased for ranges from 1 to 6 hours. They are priced differently compared to other spot instances.\n\nThe simulations below all you to see the results when spot blocks are used to complete the collection of tasks.\n`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":1150,"value":"viewof spotBlockDurationHours = slider({\n min: 1,\n max: 6,\n step: 1,\n value: 3,\n title: \"EC2 Spot Block Duration (hours):\"\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":1157,"value":"viewof spotBlockPrice = slider({\n min: 0.01,\n max: 10,\n step: 0.01,\n value: 0.68,\n title: `Cost of the EC2 spot block with the specified duration of ${spotBlockDurationHours} hours. (dollars):`\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":1250,"value":"simulationStatsReport(\n \"Parallel Task Simulation Results With Spot Blocks and Checkpoints\",\n simStats.blocks,\n simStats.blocksCheckpoints,\n true\n)","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":1334,"value":"md`*Note: If the spot block length is less than the task time, the collection of tasks cannot be completed without checkpoints. This may cause $NaN to be reported.*\n\n-----\n\n*If the individual task time varies you will see distributions of values below, otherwise single values will be reported as spot blocks aren't subject to interruption at random intervals in this simulation.*`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":1304,"value":"md`### Histogram of Simulated Maximum Wall Clock Time for Completion of All ${numberOfTasks} Tasks With Spot Blocks`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":1306,"value":"{\n const d = fullTaskSimulationsSpotBlocks.map(r => r.maxWallClockSeconds);\n return chart2(\n Math.min(...d),\n Math.max(...d),\n d,\n 300,\n \"Wall Clock Seconds\",\n \"Occurrances\"\n );\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":1310,"value":"md`### Histogram of Simulated Cost for Completion of All ${numberOfTasks} Tasks With Spot Blocks`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":1314,"value":"{\n const d2 = fullTaskSimulationsSpotBlocks.map(\n r => (r.billedSeconds * costPerHourCPU) / 60 / 100\n );\n return chart2(\n Math.min(...d2),\n Math.max(...d2),\n d2,\n 300,\n \"Dollars\",\n \"Occurrances\"\n );\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":1294,"value":"md`### Histogram of Simulated Maximum Wall Clock Time for Completion of All ${numberOfTasks} Tasks With Spot Blocks and Checkpoints `","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":1298,"value":"{\n const d = fullTaskSimulationsSpotBlocksWithCheckpoints.map(\n r => r.maxWallClockSeconds\n );\n return chart2(\n Math.min(...d),\n Math.max(...d),\n d,\n 300,\n \"Wall Clock Seconds\",\n \"Occurrances\"\n );\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":1312,"value":"md`### Histogram of Simulated Cost for Completion of All ${numberOfTasks} Tasks With Spot Blocks And Checkpoints`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":1316,"value":"{\n const d2 = fullTaskSimulationsSpotBlocksWithCheckpoints.map(\n r => (r.billedSeconds * costPerHourCPU) / 60 / 100\n );\n return chart2(\n Math.min(...d2),\n Math.max(...d2),\n d2,\n 300,\n \"Dollars\",\n \"Occurrances\"\n );\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":901,"value":"md`## Conclusions\n\nIt is great to allow long running tasks to save and resume from checkpoints. It can vastly increase the amount of savings from AWS EC2 spot instances. If you tasks cannot checkpoint themselves hopefully these simulations have given you a better understanding of how your task execution will perform. \n\nI'm very interested in any thoughts you have about this notebook. Please fork it or send me suggestions.\n\n`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":1241,"value":"md`### Simulation speed and quality controls:\n\nThe simulation is controlled by the variables below to determine how many simulations are performed along with how many times to allow retries before giving up on the completion of tasks. Having too low of a success rate for tasks will lead to longer simulations, but without enough simulations performed the results may not be as accurate as desired.`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":1167,"value":"// This is the overall knob that determines how many simulations are performed in each section.\ndesiredSimulationCount = 1000","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":1208,"value":"// How many retries should be performed when attempting to simulate a group of tasks\n// to be completed (different from the individual task with retries using checkpoints).\ngroupTaskSimulationCount = 1000","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":1205,"value":"// How many times to simulate a retry to process a task when checkpoints are in use,\n// adjust as necessary when the probability of success is low.\nmaxCheckpointRetries = 1000","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":904,"value":"md`### Calculations and Variables Follow`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":1143,"value":"instanceStartupSeconds = instanceStartupMinutes * 60","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":945,"value":"checkpointSaveSeconds = checkpointSaveMinutes * 60","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":946,"value":"checkpointRestoreSeconds = checkpointRestoreMinutes * 60","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":949,"value":"checkpointSeconds = checkpointMinutes * 60","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":375,"value":"function taskLengthSecondsGen() {\n // Just convert the talk length to whole seconds.\n return Math.round(taskLengthMinutes() * 60);\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":218,"value":"$31","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":209,"value":"$32","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":704,"value":"summarizeSeries = (data, names) => {\n const r = {};\n names.map(name => {\n const d = data.map(r => r[name]);\n r[name] = {\n mean: d3a.mean(d),\n sd: d3a.deviation(d)\n };\n });\n return r;\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":249,"value":"fullTaskSimulations = {\n const result = [];\n for (var i = 0; i < desiredSimulationCount; i++) {\n const r = taskSimulations(false);\n if (r.wasAbleToFill) {\n result.push(r);\n } else {\n return [];\n }\n }\n return result;\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":1173,"value":"fullTaskSimulationsSpotBlocks = {\n const result = [];\n for (var i = 0; i < desiredSimulationCount; i++) {\n const r = taskSimulations(false, true);\n if (r.wasAbleToFill) {\n result.push(r);\n } else {\n return [];\n }\n }\n return result;\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":1199,"value":"fullTaskSimulationsSpotBlocksWithCheckpoints = {\n const result = [];\n for (var i = 0; i < desiredSimulationCount; i++) {\n const r = taskSimulations(true, true);\n if (r.wasAbleToFill) {\n result.push(r);\n } else {\n return [];\n }\n }\n return result;\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":702,"value":"fullTaskSimulationsWithCheckpoints = {\n const result = [];\n for (var i = 0; i < desiredSimulationCount; i++) {\n const r = taskSimulations(true);\n if (r.wasAbleToFill) {\n result.push(r);\n } else {\n return [];\n }\n }\n return result;\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":1256,"value":"simStats = {\n const result = {};\n const t = [\n ['normalCheckpoints', fullTaskSimulationsWithCheckpoints],\n ['normal', fullTaskSimulations],\n ['blocks', fullTaskSimulationsSpotBlocks],\n ['blocksCheckpoints', fullTaskSimulationsSpotBlocksWithCheckpoints]\n ];\n t.map(r => {\n result[r[0]] = summarizeSeries(r[1], [\n 'attempts',\n 'billedSeconds',\n 'maxWallClockSeconds',\n 'freeTerminationSeconds',\n 'writtenCheckpoints',\n 'totalTaskLengthSeconds'\n ]);\n });\n return result;\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":261,"value":"d3a = require(\"d3-array\")","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":239,"value":"$33","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":127,"value":"simulationsCompletedSuccessfully = sampleMaximumResults.reduce(\n (c, r) => (r >= simpleTaskCutoffSeconds ? c + 1 : c),\n 0\n)","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":1091,"value":"// For the first simple introduction chart pick a cutoff value to indicate success\nsimpleTaskCutoffSeconds = taskLengthSecondsGen()","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":16,"value":"sampleMaximumResults = {\n var allResults = [];\n for (var i = 0; i < numberOfSamples; i++) {\n const result = simulateTaskRun(simpleTaskCutoffSeconds);\n allResults.push(result.taskProgressSeconds);\n }\n return allResults;\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":288,"value":"$34","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":24,"value":"d3 = require(\"d3@5\")","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":28,"value":"margin = ({ top: 20, right: 20, bottom: 40, left: 40 })","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":30,"value":"height = 200","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":39,"value":"x = d3\n .scaleLinear()\n .domain(d3.extent(sampleMaximumResults))\n .nice()\n .range([margin.left, width - margin.right - 40])","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":38,"value":"bins = d3\n .histogram()\n .domain(x.domain())\n .thresholds(x.ticks(16))(sampleMaximumResults)","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":36,"value":"y = d3\n .scaleLinear()\n .domain([0, d3.max(bins, d => d.length)])\n .nice()\n .range([height - margin.bottom, margin.top])","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":42,"value":"xAxis = g =>\n g\n .attr(\"transform\", `translate(0,${height - margin.bottom})`)\n .call(d3.axisBottom(x).tickSizeOuter(0))\n .call(g =>\n g\n .append(\"text\")\n .attr(\"x\", width - margin.right)\n .attr(\"y\", 24)\n .attr(\"fill\", \"#000\")\n .attr(\"font-weight\", \"bold\")\n .attr(\"text-anchor\", \"end\")\n .text(\"Lifespan in Seconds\")\n )","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":32,"value":"yAxis = g =>\n g\n .attr(\"transform\", `translate(${margin.left},0)`)\n .call(d3.axisLeft(y))\n .call(g => g.select(\".domain\").remove())\n .call(g =>\n g\n .select(\".tick:last-of-type text\")\n .clone()\n .attr(\"y\", -16)\n .attr(\"text-anchor\", \"start\")\n .attr(\"font-weight\", \"bold\")\n .text(\"Count of Samples\")\n )","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":2,"value":"import { slider } from \"@jashkenas/inputs\"","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":661,"value":"import { checkbox } from \"@jashkenas/inputs\"","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":1114,"value":"moment = require('moment')","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"}],"files":"$W35","stdlib":"1","titling":"auto"}} 2f:"$2e:body"