From a3b9e1a0aca6ff66b4686876323d500a8008b4e4 Mon Sep 17 00:00:00 2001
From: Andre Medeiros <me@andremedeiros.info>
Date: Sat, 10 Jul 2021 00:59:34 -0400
Subject: [PATCH] fix up redis so that we only parse the script once

---
 cmd/apollo-scheduler/main.go | 46 ++++++++++++++++++++++--------------
 1 file changed, 28 insertions(+), 18 deletions(-)

diff --git a/cmd/apollo-scheduler/main.go b/cmd/apollo-scheduler/main.go
index 7b765a7..bf4b9ed 100644
--- a/cmd/apollo-scheduler/main.go
+++ b/cmd/apollo-scheduler/main.go
@@ -104,8 +104,14 @@ func main() {
 		}
 	}
 
+	// Eval lua so that we don't keep parsing it
+	luaSha, err := evalScript(ctx, redisConn)
+	if err != nil {
+		panic(err)
+	}
+
 	s := gocron.NewScheduler(time.UTC)
-	s.Every(1).Second().Do(func() { enqueueAccounts(ctx, logger, statsd, pool, redisConn, notificationsQueue) })
+	s.Every(1).Second().Do(func() { enqueueAccounts(ctx, logger, statsd, pool, redisConn, luaSha, notificationsQueue) })
 	s.Every(1).Minute().Do(func() { reportStats(ctx, logger, statsd, pool, redisConn) })
 	s.StartAsync()
 
@@ -123,6 +129,25 @@ func main() {
 	s.Stop()
 }
 
+func evalScript(ctx context.Context, redisConn *redis.Client) (string, error) {
+	lua := fmt.Sprintf(`
+		local retv={}
+		local ids=cjson.decode(ARGV[1])
+
+		for i=1, #ids do
+			local key = KEYS[1] .. ":" .. ids[i]
+			if redis.call("exists", key) == 0 then
+				redis.call("setex", key, %d, 1)
+				retv[#retv + 1] = ids[i]
+			end
+		end
+
+		return retv
+	`, checkTimeout)
+
+	return redisConn.ScriptLoad(ctx, lua).Result()
+}
+
 func reportStats(ctx context.Context, logger *logrus.Logger, statsd *statsd.Client, pool *pgxpool.Pool, redisConn *redis.Client) {
 	var (
 		count int64
@@ -147,7 +172,7 @@ func reportStats(ctx context.Context, logger *logrus.Logger, statsd *statsd.Clie
 	}
 }
 
-func enqueueAccounts(ctx context.Context, logger *logrus.Logger, statsd *statsd.Client, pool *pgxpool.Pool, redisConn *redis.Client, queue rmq.Queue) {
+func enqueueAccounts(ctx context.Context, logger *logrus.Logger, statsd *statsd.Client, pool *pgxpool.Pool, redisConn *redis.Client, luaSha string, queue rmq.Queue) {
 	start := time.Now()
 
 	now := float64(time.Now().UnixNano()/int64(time.Millisecond)) / 1000
@@ -216,22 +241,7 @@ func enqueueAccounts(ctx context.Context, logger *logrus.Logger, statsd *statsd.
 			"len": len(batch),
 		}).Debug("enqueueing batch")
 
-		lua := fmt.Sprintf(`
-			local retv={}
-			local ids=cjson.decode(ARGV[1])
-
-			for i=1, #ids do
-				local key = "locks:accounts:" .. ids[i]
-				if redis.call("exists", key) == 0 then
-					redis.call("setex", key, %d, 1)
-					retv[#retv + 1] = ids[i]
-				end
-			end
-
-			return retv
-		`, checkTimeout)
-
-		res, err := redisConn.Eval(ctx, lua, []string{}, batch).Result()
+		res, err := redisConn.EvalSha(ctx, luaSha, []string{"locks:accounts"}, batch).Result()
 		if err != nil {
 			logger.WithFields(logrus.Fields{
 				"err": err,