Run the automated benchmark and Benchstat runner

With rexec_sweet installed, your benchmarking instances running, and your local machine authenticated with GCP, you’re ready to run automated benchmarks across your configured environments.

Run an automated benchmark and generate results

To begin, open a terminal on your local machine and run:

    

        
        
rexec-sweet

    

The tool will prompt you to choose a benchmark.

Press Enter to run the default benchmark, markdown, which is a good starting point for your first run.

    

        
        
Available benchmarks:
1. biogo-igor
2. biogo-krishna
3. bleve-index
4. cockroachdb
5. esbuild
6. etcd
7. go-build
8. gopher-lua
9. markdown (default)
10. tile38
Enter number (1-10) [default: markdown]:

    

The tool then detects your running GCP instances and displays them. You’ll be asked whether you want to use the first two instances it finds and the default install paths.

    

        
        Available instances:
1. c4 (will be used as first instance)
2. c4a (will be used as second instance)

Do you want to run the first two instances found with default install directories? [Y/n]:

        
    

You can accept the defaults by pressing Enter, which uses the instances listed and assumes Go and Sweet were installed to ~/benchmarks/sweet.

If you’re running more than two instances or installed Go and Sweet to a non-default location, enter n and follow the prompts to manually select instances and specify custom install paths.

In this example, you’ll manually select the instances and paths as shown below:

    

        
        Available instances:
1. c4 (will be used as first instance)
2. c4a (will be used as second instance)

Do you want to run the first two instances found with default install directories? [Y/n]: n

Select 1st instance:
1. c4
2. c4a
Enter number (1-2): 1
Enter remote path for c4 [default: ~/benchmarks/sweet]:

Select 2nd instance:
1. c4
2. c4a
Enter number (1-2): 2
Enter remote path for c4a [default: ~/benchmarks/sweet]:
Output directory: /private/tmp/a/go_benchmarks/results/c4-c4a-markdown-20250610T190407
...

        
    

After selecting instances and paths, the tool will:

• Run the selected benchmark on both VMs
• Use benchstat to compare the results
• Push the results to your local machine

    

        
        Running benchmarks on the selected instances...
[c4a] [sweet] Work directory: /tmp/gosweet3216239593
[c4] [sweet] Work directory: /tmp/gosweet2073316306...
[c4a] ✅ benchmark completed
[c4] ✅ benchmark completed
...
Report generated in results/c4-c4a-markdown-20250610T190407

        
    

View the report

Once on your local machine, rexec_sweet will generate an HTML report that opens automatically in your web browser.

If you close the report, you can reopen it by navigating to the results subdirectory and opening report.html in your browser.

Sample HTML report

Upon completion, the tool generates a report in the results subdirectory of the current working directory, which opens automatically in your web browser to view the benchmark results and comparisons.