From fe8e8b5d70aeba5711cab0fa9ac35555bfc96452 Mon Sep 17 00:00:00 2001
From: Tsvetoslav Tsekov <129774811+tsekovTriesCoding@users.noreply.github.com>
Date: Wed, 18 Mar 2026 15:20:44 +0200
Subject: [PATCH] feat: switch Spring Cloud LoadBalancer to Caffeine cache for
 production

- Add spring-boot-starter-cache and caffeine dependencies to parent POM
- Configure LoadBalancer Caffeine cache in api-gateway (ttl=35s, capacity=256)
- Configure LoadBalancer Caffeine cache in auth-service (ttl=35s, capacity=256)
- Replaces default ConcurrentHashMap cache with production-recommended Caffeine
---
 .../api-gateway/src/main/resources/application.yaml  |  8 ++++++++
 .../auth-service/src/main/resources/application.yaml |  8 ++++++++
 backend/pom.xml                                      | 12 ++++++++++++
 3 files changed, 28 insertions(+)

diff --git a/backend/api-gateway/src/main/resources/application.yaml b/backend/api-gateway/src/main/resources/application.yaml
index 0d24aec..9297ac4 100644
--- a/backend/api-gateway/src/main/resources/application.yaml
+++ b/backend/api-gateway/src/main/resources/application.yaml
@@ -16,6 +16,14 @@ spring:
     config:
       enabled: false
 
+    loadbalancer:
+      cache:
+        enabled: true
+        ttl: 35s
+        capacity: 256
+        caffeine:
+          spec: initialCapacity=64,expireAfterWrite=35s
+
     gateway:
       discovery:
         locator:
diff --git a/backend/auth-service/src/main/resources/application.yaml b/backend/auth-service/src/main/resources/application.yaml
index 7eac60e..07aad66 100644
--- a/backend/auth-service/src/main/resources/application.yaml
+++ b/backend/auth-service/src/main/resources/application.yaml
@@ -16,6 +16,14 @@ spring:
     config:
       enabled: false
 
+    loadbalancer:
+      cache:
+        enabled: true
+        ttl: 35s
+        capacity: 256
+        caffeine:
+          spec: initialCapacity=64,expireAfterWrite=35s
+
   datasource:
     url: jdbc:mysql://localhost:3306/finpay_auth?createDatabaseIfNotExist=true&useSSL=false&serverTimezone=UTC&allowPublicKeyRetrieval=true
     username: ${MYSQL_USERNAME}
diff --git a/backend/pom.xml b/backend/pom.xml
index 0b12869..6527c85 100644
--- a/backend/pom.xml
+++ b/backend/pom.xml
@@ -148,6 +148,18 @@
             <artifactId>micrometer-registry-prometheus</artifactId>
         </dependency>
 
+        <!-- Spring Cache (provides CaffeineCacheManager for Spring Cloud LoadBalancer) -->
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-cache</artifactId>
+        </dependency>
+
+        <!-- Caffeine Cache (high-performance cache for Spring Cloud LoadBalancer in production) -->
+        <dependency>
+            <groupId>com.github.ben-manes.caffeine</groupId>
+            <artifactId>caffeine</artifactId>
+        </dependency>
+
         <!-- SpringDoc OpenAPI -->
         <dependency>
             <groupId>org.springdoc</groupId>