From bde8ac2db7d2018681d8da7f56960e195723e12b Mon Sep 17 00:00:00 2001
From: Michael Hohn <hohn@github.com>
Date: Mon, 12 May 2025 14:59:59 -0700
Subject: [PATCH] Drop dynamic worker count; set default to 1

---
 cmd/agent/main.go  |   2 +-
 pkg/agent/agent.go | 101 +++++++++------------------------------------
 2 files changed, 20 insertions(+), 83 deletions(-)

diff --git a/cmd/agent/main.go b/cmd/agent/main.go
index b6efcd4..3666773 100644
--- a/cmd/agent/main.go
+++ b/cmd/agent/main.go
@@ -16,7 +16,7 @@ import (
 
 func main() {
 	slog.Info("Starting agent")
-	workerCount := flag.Int("workers", 0, "number of workers")
+	workerCount := flag.Int("workers", 1, "number of workers")
 	logLevel := flag.String("loglevel", "info", "Set log level: debug, info, warn, error")
 	flag.Parse()
 
diff --git a/pkg/agent/agent.go b/pkg/agent/agent.go
index f579534..632678e 100644
--- a/pkg/agent/agent.go
+++ b/pkg/agent/agent.go
@@ -6,9 +6,7 @@ import (
 	"log/slog"
 	"os"
 	"path/filepath"
-	"runtime"
 	"sync"
-	"time"
 
 	"github.com/hohn/mrvacommander/pkg/artifactstore"
 	"github.com/hohn/mrvacommander/pkg/codeql"
@@ -17,7 +15,6 @@ import (
 	"github.com/hohn/mrvacommander/pkg/queue"
 	"github.com/hohn/mrvacommander/utils"
 
-	"github.com/elastic/go-sysinfo"
 	"github.com/google/uuid"
 )
 
@@ -51,41 +48,9 @@ func (r *RunnerSingle) worker(wid int) {
 */
 
 const (
-	workerMemoryMB     = 2048 // 2 GB
-	monitorIntervalSec = 10   // Monitor every 10 seconds
+	workerMemoryMB = 2048 // 2 GB
 )
 
-func calculateWorkers() int {
-	host, err := sysinfo.Host()
-	if err != nil {
-		slog.Error("failed to get host info", "error", err)
-		os.Exit(1)
-	}
-
-	memInfo, err := host.Memory()
-	if err != nil {
-		slog.Error("failed to get memory info", "error", err)
-		os.Exit(1)
-	}
-
-	// Get available memory in MB
-	totalMemoryMB := memInfo.Available / (1024 * 1024)
-
-	// Ensure we have at least one worker
-	workers := int(totalMemoryMB / workerMemoryMB)
-	if workers < 1 {
-		workers = 1
-	}
-
-	// Limit the number of workers to the number of CPUs
-	cpuCount := runtime.NumCPU()
-	if workers > cpuCount {
-		workers = max(cpuCount, 1)
-	}
-
-	return workers
-}
-
 func StartAndMonitorWorkers(ctx context.Context,
 	artifacts artifactstore.Store,
 	databases qldbstore.Store,
@@ -93,57 +58,29 @@ func StartAndMonitorWorkers(ctx context.Context,
 	desiredWorkerCount int,
 	wg *sync.WaitGroup) {
 
-	currentWorkerCount := 0
-	stopChans := make([]chan struct{}, 0)
-
-	if desiredWorkerCount != 0 {
-		slog.Info("Starting workers", slog.Int("count", desiredWorkerCount))
-		for i := 0; i < desiredWorkerCount; i++ {
-			stopChan := make(chan struct{})
-			stopChans = append(stopChans, stopChan)
-			wg.Add(1)
-			go RunWorker(ctx, artifacts, databases, queue, stopChan, wg)
-		}
-		return
+	var workerCount int
+	if desiredWorkerCount > 0 {
+		workerCount = desiredWorkerCount
+		slog.Info("Starting fixed number of workers", slog.Int("count", workerCount))
+	} else {
+		workerCount = 1
+		slog.Info("Starting preset number of workers", slog.Int("count", workerCount))
 	}
 
-	slog.Info("Worker count not specified, managing based on available memory and CPU")
+	stopChans := make([]chan struct{}, workerCount)
 
-	for {
-		select {
-		case <-ctx.Done():
-			// signal all workers to stop
-			for _, stopChan := range stopChans {
-				close(stopChan)
-			}
-			return
-		default:
-			newWorkerCount := calculateWorkers()
+	for i := 0; i < workerCount; i++ {
+		stopChan := make(chan struct{})
+		stopChans[i] = stopChan
+		wg.Add(1)
+		go RunWorker(ctx, artifacts, databases, queue, stopChan, wg)
+	}
 
-			if newWorkerCount != currentWorkerCount {
-				slog.Info(
-					"Modifying worker count",
-					slog.Int("current", currentWorkerCount),
-					slog.Int("new", newWorkerCount))
-			}
+	// Wait for context cancellation
+	<-ctx.Done()
 
-			if newWorkerCount > currentWorkerCount {
-				for i := currentWorkerCount; i < newWorkerCount; i++ {
-					stopChan := make(chan struct{})
-					stopChans = append(stopChans, stopChan)
-					wg.Add(1)
-					go RunWorker(ctx, artifacts, databases, queue, stopChan, wg)
-				}
-			} else if newWorkerCount < currentWorkerCount {
-				for i := newWorkerCount; i < currentWorkerCount; i++ {
-					close(stopChans[i])
-				}
-				stopChans = stopChans[:newWorkerCount]
-			}
-			currentWorkerCount = newWorkerCount
-
-			time.Sleep(monitorIntervalSec * time.Second)
-		}
+	for _, stopChan := range stopChans {
+		close(stopChan)
 	}
 }