Add option to disable fallback after failure

Author: ajayyy

src/config.ts

@@ -88,7 +88,8 @@ addDefaults(config, {
         readTimeout: 250,
         max: 10,
         idleTimeoutMillis: 10000,
-        maxTries: 3
+        maxTries: 3,
+        fallbackOnFail: true
     },
     dumpDatabase: {
         enabled: false,

src/databases/Postgres.ts

@@ -148,8 +148,10 @@ export class Postgres implements IDatabase {
 
     private getPool(type: string, options: QueryOption): Pool {
         const readAvailable = this.poolRead && options.useReplica && this.isReadQuery(type);
-        const ignroreReadDueToFailure = this.lastPoolReadFail > Date.now() - 1000 * 30;
-        const readDueToFailure = this.lastPoolFail > Date.now() - 1000 * 30;
+        const ignroreReadDueToFailure = this.config.postgresReadOnly.fallbackOnFail
+            && this.lastPoolReadFail > Date.now() - 1000 * 30;
+        const readDueToFailure = this.config.postgresReadOnly.fallbackOnFail
+            && this.lastPoolFail > Date.now() - 1000 * 30;
         if (readAvailable && !ignroreReadDueToFailure && (options.forceReplica || readDueToFailure ||
                 Math.random() > 1 / (this.config.postgresReadOnly.weight + 1))) {
             return this.poolRead;