Fix Critical Database Performance and Hibernate Issues

pet_clinic_insurance_service/pet_clinic_insurance_service/settings.py

@@ -117,6 +117,14 @@ def get_secret_value(secret_name: str, region_name: str) -> str:
         "PASSWORD": DB_PASSWORD,
         "HOST": os.environ.get("DB_SERVICE_HOST"),
         "PORT": os.environ.get("DB_SERVICE_PORT"),
+        # Database connection pool optimization
+        "CONN_MAX_AGE": 600,  # Keep connections alive for 10 minutes
+        "OPTIONS": {
+            "MAX_CONNS": 20,  # Maximum number of connections
+            "MIN_CONNS": 5,   # Minimum number of connections
+            "connect_timeout": 10,  # Connection timeout in seconds
+            "options": "-c default_transaction_isolation=read_committed"
+        }
     }
 }
 
@@ -138,6 +146,11 @@ def get_secret_value(secret_name: str, region_name: str) -> str:
             'level': 'INFO',
             'propagate': True,
         },
+        'django.db.backends': {
+            'handlers': ['console'],
+            'level': 'WARNING',  # Log slow queries
+            'propagate': False,
+        },
     },
 }
 
@@ -180,4 +193,4 @@ def get_secret_value(secret_name: str, region_name: str) -> str:
 # Default primary key field type
 # https://docs.djangoproject.com/en/5.0/ref/settings/#default-auto-field
 
-DEFAULT_AUTO_FIELD = "django.db.models.BigAutoField"
+DEFAULT_AUTO_FIELD = "django.db.models.BigAutoField"

spring-petclinic-customers-service/src/main/java/org/springframework/samples/petclinic/customers/model/OwnerRepository.java

@@ -16,6 +16,9 @@
 package org.springframework.samples.petclinic.customers.model;
 
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Modifying;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.transaction.annotation.Transactional;
 
 /**
  * Repository class for <code>Owner</code> domain objects All method names are compliant with Spring Data naming
@@ -27,4 +30,14 @@
  * @author Michael Isvy
  * @author Maciej Szarlinski
  */
-public interface OwnerRepository extends JpaRepository<Owner, Integer> { }
+public interface OwnerRepository extends JpaRepository<Owner, Integer> {
+
+    /**
+     * Custom delete method to prevent StackOverflowError in deleteAllInBatch
+     * Uses native SQL to avoid Hibernate HQL parsing issues
+     */
+    @Modifying
+    @Transactional
+    @Query(value = "DELETE FROM owners", nativeQuery = true)
+    void deleteAllOwners();
+}

spring-petclinic-customers-service/src/main/resources/application.yml

@@ -4,6 +4,18 @@ spring:
   config:
     import: optional:configserver:${CONFIG_SERVER_URL:http://localhost:8888/}
 
+# HTTP client timeout configuration to prevent ResourceAccessException
+server:
+  tomcat:
+    connection-timeout: 60000  # 60 seconds
+    keep-alive-timeout: 60000
+
+# RestTemplate and WebClient timeout configuration
+rest:
+  client:
+    connection-timeout: 30000  # 30 seconds
+    read-timeout: 60000        # 60 seconds
+
 eureka:
   instance:
     preferIpAddress: true
@@ -16,6 +28,7 @@ logging:
     root: OFF
     org.springframework.samples.petclinic.customers.web.PetResource: INFO
     org.springframework.samples.petclinic.customers.aws.SqsService: FATAL
+    org.springframework.web.client.RestTemplate: WARN  # Log HTTP client errors
   pattern:
     level: trace_id=%mdc{trace_id} span_id=%mdc{span_id} trace_flags=%mdc{trace_flags} %5p