Reusing redis client

app/server/lib/AuditLogger.ts

@@ -99,7 +99,7 @@ export class AuditLogger implements IAuditLogger {
     "AuditLogger ",
     (requestOrSession) => getLogMeta(requestOrSession)
   );
-  private _redisSubscriber: RedisClient | undefined;
+  private _redisClient: RedisClient | null = null;
   private _redisChannel = `${getPubSubPrefix()}-audit-logger-streaming-destinations:change`;
   private _createdPromises: Set<Promise<any>>|null = new Set();
   private _closed = false;
@@ -113,6 +113,7 @@ export class AuditLogger implements IAuditLogger {
   }
 
   public async close(timeout = 10_000) {
+    // Wait 10 seconds for all promises to complete
     const start = Date.now();
     this._closed = true;
     while(this._createdPromises?.size) {
@@ -126,10 +127,17 @@ export class AuditLogger implements IAuditLogger {
         this._logger.error(null, "failed to close audit logger", error);
       });
     }
+
+    // Remove the set, it will prevent from adding new promises. This is just sanity check, as
+    // code already tests for this._closed before adding new promises.
     this._createdPromises = null;
+
+    // Clear up TTL Maps that have timers associated with them.
     this._installStreamingDestinations.clear();
     this._orgStreamingDestinations.clear();
-    await this._redisSubscriber?.quitAsync();
+
+    // Close the redis clients if they weren't already.
+    await this._redisClient?.quitAsync();
   }
 
   /**
@@ -327,13 +335,13 @@ export class AuditLogger implements IAuditLogger {
       return;
     }
 
-    this._redisSubscriber = createClient(process.env.REDIS_URL);
-    this._redisSubscriber.subscribe(this._redisChannel);
-    this._redisSubscriber.on("message", async (message) => {
+    this._redisClient ??= createClient(process.env.REDIS_URL);
+    this._redisClient.subscribe(this._redisChannel);
+    this._redisClient.on("message", async (message) => {
       const { orgId } = JSON.parse(message);
       this._invalidateStreamingDestinations(orgId);
     });
-    this._redisSubscriber.on("error", async (error) => {
+    this._redisClient.on("error", async (error) => {
       this._logger.error(
         null,
         `encountered error while subscribed to channel ${this._redisChannel}`,
@@ -346,10 +354,9 @@ export class AuditLogger implements IAuditLogger {
     if (!process.env.REDIS_URL) {
       return;
     }
-
-    const redis = createClient(process.env.REDIS_URL);
+    this._redisClient ??= createClient(process.env.REDIS_URL);
     try {
-      await redis.publishAsync(this._redisChannel, JSON.stringify({ orgId }));
+      await this._redisClient.publishAsync(this._redisChannel, JSON.stringify({ orgId }));
     } catch (error) {
       this._logger.error(
         null,
@@ -359,8 +366,6 @@ export class AuditLogger implements IAuditLogger {
           orgId,
         }
       );
-    } finally {
-      await redis.quitAsync();
     }
   }