How to exit middleware gracefully？ #1265
Comments
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/probe can you confirm? |
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Yes, I can confirm the issue with middleware zombie processes in GoReplay. After analyzing the code, I've identified the root cause and can provide a solution. The IssueWhen GoReplay runs with a middleware (
However, this doesn't always properly terminate the middleware process, resulting in a zombie process. Root CauseThe current implementation in
SolutionTo fix this issue, middleware implementations in Go should:
Here's an example of a properly implemented middleware in Go: package main
import (
"bufio"
"encoding/hex"
"fmt"
"os"
"os/signal"
"syscall"
)
func main() {
// Set up signal handling
sigChan := make(chan os.Signal, 1)
signal.Notify(sigChan, syscall.SIGINT, syscall.SIGTERM)
// Create a done channel to coordinate shutdown
done := make(chan struct{})
// Start processing in a goroutine
go func() {
scanner := bufio.NewScanner(os.Stdin)
for scanner.Scan() {
// Process input and write output
line := scanner.Bytes()
// Your middleware logic here
fmt.Fprintf(os.Stdout, "%s\n", line)
}
close(done)
}()
// Wait for either a signal or processing to complete
select {
case <-sigChan:
fmt.Fprintln(os.Stderr, "Signal received, shutting down...")
case <-done:
fmt.Fprintln(os.Stderr, "Processing complete")
}
// Perform any cleanup needed
// No need to explicitly exit - the program will exit naturally
}This implementation ensures that:
With this approach, the middleware process will terminate gracefully when GoReplay exits, preventing zombie processes. Tip: Start comment with |
Start goreplay and middleware with
goreplay --middleware /app/middleware, which handles signals like syscall.SIGINT, syscall.SIGTERM, etc. After the goreplay process is terminated, middleware also exits, but a middleware zombie process is formed. How to implement middleware correctly with golang?The text was updated successfully, but these errors were encountered: