### Run Clinic.js Doctor with Autocannon Example

Source: https://clinicjs.org/documentation/index

Clones an example application repository, installs its dependencies, and then runs Clinic.js Doctor with autocannon to profile an app with a known I/O issue. This process automatically launches the Doctor tool in the browser upon completion.

```bash
git clone https://github.com/clinicjs/node-clinic-doctor-examples.git
```

```bash
cd node-clinic-doctor-examples
```

```bash
npm install
```

```bash
clinic doctor --autocannon [ / ] -- node ./slow-io
```

--------------------------------

### Install Clinic.js

Source: https://clinicjs.org/documentation/doctor/01-setup

Installs the Clinic.js command-line tool globally using npm.

```bash
npm install -g clinic
```

--------------------------------

### Check Bubbleprof installation and help

Source: https://clinicjs.org/documentation/bubbleprof/01-setup

Verifies the installation of Bubbleprof and displays its help information.

```bash
clinic bubbleprof --help
```

--------------------------------

### Verify Heap Profiler Installation

Source: https://clinicjs.org/documentation/heapprofiler/01-setup

Checks if the Heap Profiler has been installed correctly by running its help command. This verifies the installation and shows available options.

```bash
clinic heapprofiler --help
```

--------------------------------

### Check Clinic Doctor Installation

Source: https://clinicjs.org/documentation/doctor/01-setup

Verifies that Clinic Doctor has been installed correctly by displaying its help information.

```bash
clinic doctor --help
```

--------------------------------

### Get Help for Clinic.js Sub-commands

Source: https://clinicjs.org/documentation/index

Provides detailed help information for specific Clinic.js sub-commands, such as 'doctor', 'bubbleprof', 'clean', 'flame', and 'heapprofiler'. This is useful for understanding the options and usage of each tool.

```bash
clinic doctor --help
```

```bash
clinic bubbleprof --help
```

```bash
clinic clean --help
```

```bash
clinic flame --help
```

```bash
clinic heapprofiler --help
```

--------------------------------

### Verify Flame Installation

Source: https://clinicjs.org/documentation/flame/01-setup

Checks if the Clinic.js Flame tool is installed correctly by running its help command. This command should display version information and usage instructions.

```bash
clinic flame --help
```

--------------------------------

### Clone Bubbleprof Demo Repository

Source: https://clinicjs.org/documentation/bubbleprof/02-getting-ready

Clones the official Bubbleprof example repository from GitHub. This repository contains a server designed for profiling async operations and includes instructions for setting up MongoDB with npm data.

```bash
git clone https://github.com/clinicjs/node-clinic-bubbleprof-demo.git
```

--------------------------------

### Install autocannon with npm

Source: https://clinicjs.org/documentation/bubbleprof/03-first-analysis

Installs the autocannon tool globally using npm. Autocannon is used to send a large number of HTTP requests to the server for performance testing.

```bash
npm install -g autocannon
```

--------------------------------

### Run Bubbleprof on a Node.js script

Source: https://clinicjs.org/documentation/bubbleprof/01-setup

Starts profiling a Node.js application using Bubbleprof.

```bash
clinic bubbleprof -- node server.js
```

--------------------------------

### Run Clinic.js Flame Profiling

Source: https://clinicjs.org/documentation/flame/01-setup

Starts profiling a Node.js application using Clinic.js Flame. It analyzes the `server.js` file to identify synchronous bottlenecks and generates a flamegraph visualization.

```bash
clinic flame -- node server.js
```

--------------------------------

### Get Clinic.js help information

Source: https://clinicjs.org/documentation/cli/04-reference

Displays help text, including example commands and supported flags for Clinic.js or specific tools, using the '--help' or '-h' flag.

```bash
clinic --help
```

```bash
clinic -h
```

```bash
clinic doctor --help
```

```bash
clinic doctor -h
```

--------------------------------

### Visualize Profiling Data

Source: https://clinicjs.org/documentation/doctor/01-setup

Builds or rebuilds the visualization from collected profiling data. Requires the path to the sample data file.

```bash
clinic doctor --visualize-only PID.clinic-doctor-sample
```

--------------------------------

### Run Clinic.js Flame Analysis

Source: https://clinicjs.org/documentation/flame/03-first-analysis

Executes a Node.js application with Clinic.js Flame, profiling it under simulated HTTP load generated by autocannon. The --on-port flag ensures autocannon starts after the server is ready, using the dynamically assigned port.

```bash
clinic flame --on-port 'autocannon localhost:$PORT' -- node 1-server-with-slow-function.js
```

--------------------------------

### Visualize profiling data

Source: https://clinicjs.org/documentation/bubbleprof/01-setup

Builds or rebuilds the visualization from collected profiling data. Requires the path to the data file.

```bash
clinic bubbleprof --visualize-only PID.clinic-bubbleprof-sample
```

--------------------------------

### Run Heap Profiler on a Node.js Application

Source: https://clinicjs.org/documentation/heapprofiler/01-setup

Starts the Heap Profiler to analyze a Node.js application. It generates a flamegraph to identify memory leaks. The report automatically opens in a browser upon process exit.

```bash
clinic heapprofiler -- node server.js
```

--------------------------------

### Simulate Load with Autocannon

Source: https://clinicjs.org/documentation/heapprofiler/01-setup

Profiles a Node.js application while simulating load using the autocannon benchmarking tool. It accepts autocannon configuration via 'subarg' syntax.

```bash
clinic heapprofiler --autocannon [ -m POST /api/example ] -- node server.js
```

--------------------------------

### Run Clinic.js Bubbleprof with autocannon

Source: https://clinicjs.org/documentation/bubbleprof/03-first-analysis

Executes a Node.js server with Clinic.js Bubbleprof profiling. It simultaneously uses autocannon to send 500 requests (5 connections) to the server as soon as it starts listening on a port. The results are analyzed and opened in an HTML page.

```bash
clinic bubbleprof --on-port 'autocannon -c 5 -a 500 localhost:$PORT' -- node 1-server-with-no-index.js
```

--------------------------------

### Get Clinic.js version

Source: https://clinicjs.org/documentation/cli/04-reference

Checks the current installed version of Clinic.js or a specific Clinic.js tool using the '--version' or '-v' flag.

```bash
clinic --version
```

```bash
clinic -v
```

```bash
clinic doctor --version
```

```bash
clinic doctor -v
```

--------------------------------

### Visualize Heap Profile Data

Source: https://clinicjs.org/documentation/heapprofiler/01-setup

Builds or rebuilds the visualization from previously collected profiling data. This command is used when `--collect-only` was previously used, or to regenerate the report.

```bash
clinic heapprofiler --visualize-only PID.clinic.heapprofile
```

--------------------------------

### Clinic.js Flame Visualization from Data

Source: https://clinicjs.org/documentation/flame/01-setup

Builds or rebuilds the flamegraph visualization from previously collected data. This command takes a data file path as an argument.

```bash
clinic flame --visualize-only PID.clinic.flame
```

--------------------------------

### View Clinic.js Global Version

Source: https://clinicjs.org/documentation/cli

This command displays the installed version of the Clinic.js package.

```bash
clinic --version
```

--------------------------------

### Example MongoDB Query

Source: https://clinicjs.org/documentation/bubbleprof/04-bubbles

Demonstrates a typical asynchronous MongoDB query operation within a JavaScript callback, as used in Clinic.js profiling.

```javascript
col.find().sort({modified: -1}).limit(5, function (err, newest) {

```

--------------------------------

### Simulate Load with Autocannon and Dynamic Port

Source: https://clinicjs.org/documentation/heapprofiler/01-setup

Profiles a Node.js application, simulating load with autocannon, and dynamically sets the target URL using the $PORT environment variable. Dollar signs in URLs must be escaped.

```bash
clinic heapprofiler --autocannon [ -m POST 'http://localhost:$PORT/?$page=1' ] -- node server.js
```

--------------------------------

### Profile Parallel Queries with Clinic.js and Autocannon

Source: https://clinicjs.org/documentation/bubbleprof/08-parallel-queries

This command profiles a Node.js server that performs parallel queries using Clinic.js and autocannon for load testing. It helps visualize performance bottlenecks and improvements.

```shell
clinic bubbleprof --on-port 'autocannon -c 5 -a 500 localhost:$PORT' -- node 3-server-with-index-in-parallel.js
```

--------------------------------

### Run Caching Example with Clinic Bubbleprof

Source: https://clinicjs.org/documentation/bubbleprof/09-caching-the-results

Executes the Node.js script '4-server-with-caching.js' using clinic bubbleprof and autocannon to simulate load and measure performance. This command helps visualize the impact of caching on database queries.

```bash
clinic bubbleprof --on-port 'autocannon -c 5 -a 500 localhost:$PORT' -- node 4-server-with-caching.js
```

--------------------------------

### Collect profiling data without immediate processing

Source: https://clinicjs.org/documentation/bubbleprof/01-setup

Configures Bubbleprof to only collect profiling data, useful for remote servers.

```bash
clinic bubbleprof --collect-only -- node server.js
```

--------------------------------

### Clinic.js Doctor with --on-port flag

Source: https://clinicjs.org/documentation/cli/04-reference

Uses the '--on-port' flag with 'clinic doctor' to execute a command when the profiled application starts listening to a port. The example shows executing 'my-script localhost:$PORT'.

```bash
clinic doctor --on-port 'my-script localhost:$PORT' -- node server.js
```

--------------------------------

### Simulate Load with Custom Command (--on-port)

Source: https://clinicjs.org/documentation/cli/01-simulating-load

Utilize the --on-port flag to integrate any custom command for load simulation, such as globally installed tools like autocannon or wrk, or npm scripts.

```bash
clinic doctor --on-port 'autocannon localhost:$PORT' -- node server.js
```

```bash
clinic doctor --on-port 'wrk http://localhost:$PORT' -- node server.js
```

```bash
clinic doctor --on-port 'npm run load-test' -- node server.js
```

--------------------------------

### Run Clinic.js Heapprofiler with Autocannon

Source: https://clinicjs.org/documentation/heapprofiler/03-first-analysis

Executes a Node.js server with Clinic.js heapprofiler and simultaneously uses autocannon to generate load. The analysis runs for 120 seconds, producing an HTML report. It targets a Fastify server started with 'node 1-server-with-many-allocations.js'.

```bash
clinic heapprofiler --autocannon [ / --method GET -d 120 ] -- node 1-server-with-many-allocations.js
```

--------------------------------

### Collect Heap Profile Data Only

Source: https://clinicjs.org/documentation/heapprofiler/01-setup

Runs the Heap Profiler to collect profiling data without processing or visualizing it immediately. This is useful for transferring data from a remote server to a local machine for analysis.

```bash
clinic heapprofiler --collect-only -- node server.js
```

--------------------------------

### Run Heap Profiler Without Auto-Opening Report

Source: https://clinicjs.org/documentation/heapprofiler/01-setup

Profiles a Node.js application but prevents the report from automatically opening in a web browser after the process finishes. Useful for server environments or manual report viewing.

```bash
clinic heapprofiler --open=false -- node server.js
```

--------------------------------

### Clinic.js Flame Data Collection Only

Source: https://clinicjs.org/documentation/flame/01-setup

Runs Clinic.js Flame in data collection mode without processing the data immediately. This is useful for profiling on remote servers, allowing data transfer before visualization.

```bash
clinic flame --collect-only -- node server.js
```

--------------------------------

### Profile Node.js App with Autocannon Load Test

Source: https://clinicjs.org/documentation/doctor/03-first-analysis

Runs Clinic.js Doctor to profile a Node.js application ('node slow-event-loop') and simultaneously uses Autocannon to load test the application. The '--on-port' flag executes a script when the server starts listening on a port, using the dynamically assigned '$PORT' variable. This command profiles the server under concurrent requests and generates an HTML report.

```bash
clinic doctor --on-port 'autocannon localhost:$PORT' -- node slow-event-loop
```

--------------------------------

### Clinic.js Doctor with --autocannon flag

Source: https://clinicjs.org/documentation/cli/04-reference

Utilizes the '--autocannon' flag with 'clinic doctor' to pass subarguments to autocannon. The example demonstrates passing 'localhost:$PORT' to autocannon.

```bash
clinic doctor --autocannon [ 'localhost:$PORT' ] -- node server.js
```

--------------------------------

### Clinic.js Doctor with --sample-interval flag

Source: https://clinicjs.org/documentation/cli/04-reference

Adjusts the sampling rate of the 'clinic doctor' command using the '--sample-interval' flag, specifying the interval in milliseconds. The example sets the interval to 100ms.

```bash
clinic doctor --sample-interval 100 -- node server.js
```

--------------------------------

### Example Synchronous Sleep Function

Source: https://clinicjs.org/documentation/doctor/05-fixing-event-loop-problem

This JavaScript function demonstrates a synchronous sleep implementation that blocks the Node.js event loop. It uses a `while` loop to pause execution for a specified number of milliseconds.

```javascript
function sleep(ms) {
  const future = Date.now() + ms
  while (Date.now() < future);
}
```

--------------------------------

### View Clinic.js Global Help Information

Source: https://clinicjs.org/documentation/cli

This command provides general help information for the Clinic.js CLI, including its overall functionality and usage.

```bash
clinic --help
```

--------------------------------

### View Clinic.js Flame Tool Version

Source: https://clinicjs.org/documentation/cli

A simple command to quickly retrieve and display the version of the Clinic.js Flame tool.

```bash
clinic flame --version
```

--------------------------------

### Clean Clinic.js Samples

Source: https://clinicjs.org/documentation/cli/03-managing-samples

Removes all Clinic.js generated sample files and directories. Can optionally specify a path to the samples directory.

```bash
clinic clean

```

```bash
clinic clean --path ../some-other-dir

```

--------------------------------

### Autocannon: Set Concurrent Connections

Source: https://clinicjs.org/documentation/cli/01-simulating-load

Configure the number of concurrent connections for autocannon using the -c or --connections flag as a subargument.

```bash
clinic doctor --autocannon [ -c 100 / ] -- node server.js
```

--------------------------------

### Set Presentation Mode Environment Variable

Source: https://clinicjs.org/documentation/heapprofiler/05-controls

Sets the PRESENTATION_MODE environment variable to TRUE, enabling presentation mode by default for Clinic.js Heap.

```shell
export PRESENTATION_MODE=TRUE
```

--------------------------------

### Set Environment Variables for Clinic.js Doctor

Source: https://clinicjs.org/documentation/cli

Demonstrates how to set environment variables, such as NODE_ENV, before running the Clinic.js Doctor command to analyze a Node.js application.

```bash
NODE_ENV=production clinic doctor -- node server.js
```

--------------------------------

### Running Clinic.js Flame with no-turbo-inlining

Source: https://clinicjs.org/documentation/flame/08-advanced-analysis

This command runs Clinic.js Flame to capture performance data from a Node.js application. The `--no-turbo-inlining` flag disables V8's turbo-inlining optimization, revealing potentially hidden bottlenecks within the flamegraph. The `--on-port` option runs autocannon to generate load on the specified port.

```bash
clinic flame --on-port 'autocannon localhost:$PORT' -- node --no-turbo-inlining 3-server-with-reduced-call-graph.js
```

--------------------------------

### Autocannon: Use Local File for Request Body

Source: https://clinicjs.org/documentation/cli/01-simulating-load

Simplify load testing with complex data by using the -i flag to specify a local file containing the request body.

```bash
clinic doctor --autocannon [ -m POST /api/item -i my-data.json ] -- node server.js
```

--------------------------------

### Profile Node.js App with Clinic Bubbleprof

Source: https://clinicjs.org/documentation/doctor/06-fixing-io-problem

Command to generate a Clinic.js Bubbleprof profile for a Node.js application, similar to the Doctor profile command but using `bubbleprof` instead.

```bash
clinic bubbleprof --on-port 'autocannon localhost:$PORT' -- node slow-io
```

--------------------------------

### Profile Node.js App with Clinic Doctor

Source: https://clinicjs.org/documentation/doctor/06-fixing-io-problem

Command to create a Clinic.js Doctor profile for a Node.js application, targeting a specific port and running a benchmark with autocannon.

```bash
clinic doctor --on-port 'autocannon localhost:$PORT' -- node slow-io
```

--------------------------------

### Autocannon: Specify HTTP Method and Body

Source: https://clinicjs.org/documentation/cli/01-simulating-load

Test specific HTTP methods like POST and include data in the request body using the -m and -b flags respectively.

```bash
clinic doctor --autocannon [ -m POST /api/item ] -- node server.js
```

```bash
clinic doctor --autocannon [ -m POST /api/item -b '{"my": "data"}' ] -- node server.js
```

--------------------------------

### Simulate Load with Autocannon (Basic)

Source: https://clinicjs.org/documentation/cli/01-simulating-load

Use the --autocannon flag to simulate load on your server with autocannon. Clinic.js automatically resolves the $PORT variable within the autocannon arguments to the server's actual port.

```bash
clinic doctor --autocannon [ 'localhost:$PORT' ] -- node server.js
```

```bash
clinic doctor --autocannon [ / ] -- node server.js
```

--------------------------------

### Run Benchmark with Clinic.js and Autocannon

Source: https://clinicjs.org/documentation/bubbleprof/07-improving-our-latency

This command uses Clinic.js's bubbleprof tool to profile a Node.js server ('2-server-with-index.js') while running a benchmark with Autocannon. It helps visualize performance bottlenecks in different parts of the application, such as database interactions and server framework.

```bash
clinic bubbleprof --on-port 'autocannon -c 5 -a 500 localhost:$PORT' -- node 2-server-with-index.js
```

--------------------------------

### Ignore Clinic.js Samples in Git

Source: https://clinicjs.org/documentation/cli/03-managing-samples

Configures Git to ignore the '.clinic' directory, preventing sample files from being committed. This can be done per-project or globally.

```bash
.clinic

```

```bash
git config --global core.excludesfile ~/.gitignore_global
echo '.clinic' >> ~/.gitignore_global

```

--------------------------------

### Original app.get route handler

Source: https://clinicjs.org/documentation/flame/06-optimizing-a-hot-function

This snippet shows the original route handler for the '/' path. It calls the 'payload' function, which is identified as a performance bottleneck.

```javascript
app.get('/', (req, res) => {
  res.send(payload())
})
```

--------------------------------

### Running Clinic.js Flame with Manual Serialization

Source: https://clinicjs.org/documentation/flame/08-advanced-analysis

This command executes Clinic.js Flame to analyze the performance of a Node.js application after implementing manual JSON serialization. It uses autocannon to generate load and captures flamegraph data to visualize the performance impact of the optimization.

```bash
clinic flame --on-port 'autocannon localhost:$PORT' -- node 4-server-with-manual-serialization.js
```

--------------------------------

### Generate Flamegraph with Clinic.js

Source: https://clinicjs.org/documentation/flame/07-reducing-the-graph-size

Generates a flamegraph for a Node.js application using `clinic flame`. It monitors the application on a specified port and uses `autocannon` for load testing.

```bash
clinic flame --on-port 'autocannon localhost:$PORT' -- node 3-server-with-reduced-call-graph.js
```

--------------------------------

### Visualize existing Clinic.js data

Source: https://clinicjs.org/documentation/cli/02-controlling-the-output

This command uses the `--visualize-only` flag to generate or regenerate an HTML profile from existing Clinic.js data located in a specified directory.

```bash
clinic doctor --visualize-only .clinic/1234.clinic-doctor
```

--------------------------------

### Run Clinic.js Doctor and generate HTML

Source: https://clinicjs.org/documentation/cli/02-controlling-the-output

This command runs the Clinic.js Doctor tool to profile a Node.js server script and generates a compiled HTML file along with associated data files.

```bash
clinic doctor -- node server.js
```

--------------------------------

### Node.js Function with Reduced Timeouts (Optimized)

Source: https://clinicjs.org/documentation/doctor/06-fixing-io-problem

This JavaScript code snippet shows the `awaitData` function after optimization. The duration of all `setTimeout` calls has been drastically reduced from 1000ms to 1ms, simulating a significant improvement in external I/O performance.

```javascript
function awaitData(callback) {
  async.series(
    [
      done1 => setTimeout(done1, 1),
      done1 =>
        async.parallel(
          [
            done2 => setTimeout(done2, 1),
            done2 => setTimeout(done2, 1),
            done2 => setTimeout(done2, 1),
            done2 => setTimeout(done2, 1),
            done2 => setTimeout(done2, 1)
          ],
          done1
        )
    ],
    callback
  )
}
```

--------------------------------

### Generate Flame Profile with Clinic.js

Source: https://clinicjs.org/documentation/doctor/05-fixing-event-loop-problem

This command generates a Flame profile for a Node.js application. It uses `clinic flame` to profile the application and `autocannon` to generate load on the specified port. The output is used to identify performance bottlenecks.

```bash
clinic flame --on-port 'autocannon localhost:$PORT' -- node slow-event-loop
```

--------------------------------

### Manual JSON Stringification for Performance

Source: https://clinicjs.org/documentation/flame/08-advanced-analysis

This code snippet demonstrates manual JSON stringification as an alternative to `JSON.stringify`. By directly constructing the JSON string, it bypasses the overhead of the built-in function, potentially improving performance. Note that this method requires careful handling of escaping for security.

```javascript
return `{"date": ${date}, "id": "${id}"}`
```

--------------------------------

### Profiling command with Clinic.js

Source: https://clinicjs.org/documentation/flame/06-optimizing-a-hot-function

This command uses Clinic.js to profile the Node.js server after the payload function has been optimized. It uses 'autocannon' to generate load and analyzes the performance with the Flame UI.

```bash
clinic flame --on-port 'autocannon localhost:$PORT' -- node 2-server-with-optimized-function.js
```

--------------------------------

### Use clinic flame for synchronous operations

Source: https://clinicjs.org/documentation/doctor/04-reading-a-profile

When synchronous operations are suspected of blocking the event loop, `clinic flame` is recommended to pinpoint the exact cause. This tool generates flame graphs to visualize the call stack and identify long-running functions.

```shell
clinic flame -- node app.js
```

--------------------------------

### Change Clinic.js output destination

Source: https://clinicjs.org/documentation/cli/02-controlling-the-output

This command uses the `--dest` flag to specify an alternative directory for Clinic.js to generate its output files, preventing them from cluttering the project directory.

```bash
clinic doctor --dest ../some-other-dir -- node server.js
```

--------------------------------

### Node.js Function with Chained Timeouts (Original)

Source: https://clinicjs.org/documentation/doctor/06-fixing-io-problem

This JavaScript code snippet demonstrates an asynchronous function `awaitData` that uses `async.series` to execute two operations sequentially. The first operation is a `setTimeout`, and the second is an `async.parallel` block containing multiple `setTimeout` calls, simulating slow I/O operations.

```javascript
function awaitData(callback) {
  async.series(
    [
      done1 => setTimeout(done1, Math.random() * 1000),
      done1 =>
        async.parallel(
          [
            done2 => setTimeout(done2, Math.random() * 1000),
            done2 => setTimeout(done2, Math.random() * 1000),
            done2 => setTimeout(done2, Math.random() * 1000),
            done2 => setTimeout(done2, Math.random() * 1000),
            done2 => setTimeout(done2, Math.random() * 1000)
          ],
          done1
        )
    ],
    callback
  )
}
```

--------------------------------

### Original payload function generation

Source: https://clinicjs.org/documentation/flame/06-optimizing-a-hot-function

This is the original implementation of the 'payload' function, which is responsible for generating an ID and timestamp. Its inefficient algorithm leads to performance issues.

```javascript
function initPayload(idSize = 20) {
  return function payload() {
    let chars = ''
    let n = idSize
    const date = Date.now()
    const radix = 36
    n *= n * idSize
    while (n--) {
      const num = date + n
      chars += num.toString(radix).toUpperCase()
    }
    const id = chars.slice(-idSize)
    return { date, id }
  }
}
```

--------------------------------

### Collect Clinic.js data only

Source: https://clinicjs.org/documentation/cli/02-controlling-the-output

This command uses the `--collect-only` flag to prevent Clinic.js from generating an HTML file, instead producing a directory containing raw profiling data.

```bash
clinic doctor --collect-only -- node server.js
```

--------------------------------

### Optimized payload function generation

Source: https://clinicjs.org/documentation/flame/06-optimizing-a-hot-function

This is the refactored 'payload' function. It uses a more efficient algorithm for generating IDs, improving overall server performance. It includes validation for idSize and optimizes number handling.

```javascript
function initPayload(idSize = 20) {
  if (idSize < 6) throw Error('idSize must be greater than 5')
  const max = 2147483647
  var count = 0
  return function payload() {
    count = (count + 1) % max
    const date = Date.now()
    const chars = count.toString(36).toUpperCase()
    const id = '0'.repeat(idSize - chars.length) + chars
    return { date, id }
  }
}
```

--------------------------------

### Modified Express Route with Reduced Sleep

Source: https://clinicjs.org/documentation/doctor/05-fixing-event-loop-problem

This modified Express.js route handler demonstrates reducing the duration of the synchronous `sleep` call to 1 millisecond. This change aims to alleviate event loop blocking.

```javascript
server.get('/', function (req, res, next) {
  sleep(1)

```

--------------------------------

### Express Route with Synchronous Sleep

Source: https://clinicjs.org/documentation/doctor/05-fixing-event-loop-problem

This Express.js route handler includes a call to the synchronous `sleep` function, which can block the event loop. It's a common pattern to analyze when diagnosing performance issues.

```javascript
server.get('/', function(req, res, next) {
  sleep(30)
  res.send({})
  next()
})
```

=== COMPLETE CONTENT === This response contains all available snippets from this library. No additional content exists. Do not make further requests.