diff --git a/backend/main.go b/backend/main.go
index 63306e23..f03f2000 100644
--- a/backend/main.go
+++ b/backend/main.go
@@ -6,9 +6,11 @@ import (
 	"log"
 	"math/rand"
 	"os"
+	"os/signal"
 	"path"
 	"strconv"
 	"strings"
+	"syscall"
 	"time"
 
 	"srs.epita.fr/fic-server/libfic"
@@ -43,6 +45,24 @@ func watchsubdir(watcher *fsnotify.Watcher, pathname string) error {
 	}
 }
 
+func walkAndTreat(pathname string) error {
+	if ds, err := ioutil.ReadDir(pathname); err != nil {
+		return err
+	} else {
+		for _, d := range ds {
+			p := path.Join(pathname, d.Name())
+			if d.IsDir() && d.Name() != ".tmp" && d.Mode()&os.ModeSymlink == 0 {
+				if err := walkAndTreat(p); err != nil {
+					return err
+				}
+			} else if d.Mode().IsRegular() {
+				treat(p)
+			}
+		}
+		return nil
+	}
+}
+
 var ChStarted = false
 var lastRegeneration time.Time
 var skipInitialGeneration = false
@@ -127,10 +147,24 @@ func main() {
 		log.Fatal(err)
 	}
 
+	// Register SIGUSR1, SIGUSR2
+	interrupt1 := make(chan os.Signal, 1)
+	signal.Notify(interrupt1, syscall.SIGUSR1)
+	interrupt2 := make(chan os.Signal, 1)
+	signal.Notify(interrupt2, syscall.SIGUSR2)
+
 	watchedNotify := fsnotify.Create
 
 	for {
 		select {
+		case <-interrupt1:
+			log.Println("SIGUSR1 received, retreating all files in queue...")
+			walkAndTreat(SubmissionDir)
+			log.Println("SIGUSR1 treated.")
+		case <-interrupt2:
+			inQueueMutex.Lock()
+			log.Printf("SIGUSR2 received, dumping statistics:\n  parallelJobs: %d\n  genTeamQueue size: %d\n  genQueue: %d\n  Teams in queue: %v\n  Challenge started: %v\n  Last regeneration: %v\n", parallelJobs, len(genTeamQueue), len(genQueue), inGenQueue, ChStarted, lastRegeneration)
+			inQueueMutex.Unlock()
 		case ev := <-watcher.Events:
 			if d, err := os.Lstat(ev.Name); err == nil && ev.Op&fsnotify.Create == fsnotify.Create && d.Mode().IsDir() && d.Mode()&os.ModeSymlink == 0 && d.Name() != ".tmp" {
 				// Register new subdirectory