[IncidentIQ] Auto-Fix: OutOfMemoryError

[saranyakannan]

Auto-Generated Fix by IncidentIQ

This PR was created automatically by
IncidentIQ SRE Intelligence Agent.

Error Detected

OutOfMemoryError

Incident Report

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🚨 SRE INCIDENT REPORT
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📋 INCIDENT SUMMARY
Service: user-api
Severity: CRITICAL
Errors: 2
Warnings: 0
Status: ACTIVE 🚨

🔍 ERRORS DETECTED FROM CLOUD LOGGING

• HTTP 500: OutOfMemoryError - Java heap space exhausted. Memory leak detected in OrderProcessor while loading all orders into memory. (2 occurrences)

📊 LOG EVIDENCE

{
    "jsonPayload": {
      "httpStatusCode": 500,
      "message": "HTTP 500: OutOfMemoryError - Java heap space exhausted. Memory leak detected in OrderProcessor while loading all orders into memory.",
      "severity": "ERROR",
      "errorType": "OutOfMemoryError",
      "serviceName": "user-api",
      "stackTrace": "java.lang.OutOfMemoryError: Java heap space\n\tat sre.errorservice.ErrorController.outOfMemory(ErrorController.java:75)\n\tat java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)\n\tat java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)\n\tat java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)\n\tat java.base/java.lang.reflect.Method.invoke(Unknown Source)\n\tat org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:254)\n\tat org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:182)\n\tat org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:118)\n\tat org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:917)\n\tat org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:829)\n\tat org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)\n\tat org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1089)\n\tat org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:979)\n\tat org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1014)\n\tat org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:903)\n\tat jakarta.servlet.http.HttpServlet.service(HttpServlet.java:564)\n\tat org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:885)\n\tat jakarta.servlet.http.HttpServlet.service(HttpServlet.java:658)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:205)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149)\n\tat org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149)\n\tat org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100)\n\tat org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:116)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149)\n\tat org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93)\n\tat org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:116)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149)\n\tat org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201)\n",
      "endpoint": "/api/error/outofmemory",
      "environment": "production"
    },
    "timestamp": "2026-04-08T04:44:39.574934397Z",
    "severity": "ERROR"
  }

{
    "jsonPayload": {
      "severity": "ERROR",
      "message": "HTTP 500: OutOfMemoryError - Java heap space exhausted. Memory leak detected in OrderProcessor while loading all orders into memory.",
      "httpStatusCode": 500,
      "endpoint": "/api/error/outofmemory",
      "environment": "production",
      "serviceName": "user-api",
      "stackTrace": "java.lang.OutOfMemoryError: Java heap space\n\tat sre.errorservice.ErrorController.outOfMemory(ErrorController.java:75)\n\tat sre.errorservice.ErrorController.triggerAll(ErrorController.java:377)\n\tat java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)\n\tat java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)\n\tat java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)\n\tat java.base/java.lang.reflect.Method.invoke(Unknown Source)\n\tat org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:254)\n\tat org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:182)\n\tat org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:118)\n\tat org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:917)\n\tat org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:829)\n\tat org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)\n\tat org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1089)\n\tat org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:979)\n\tat org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1014)\n\tat org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:903)\n\tat jakarta.servlet.http.HttpServlet.service(HttpServlet.java:564)\n\tat org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:885)\n\tat jakarta.servlet.http.HttpServlet.service(HttpServlet.java:658)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:205)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149)\n\tat org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149)\n\tat org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100)\n\tat org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:116)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149)\n\tat org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93)\n\tat org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:116)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149)\n",
      "errorType": "OutOfMemoryError"
    },
    "timestamp": "2026-04-08T18:06:26.925236137Z",
    "severity": "ERROR"
  }

🔧 RECOMMENDED FIXES

Code Fix for OutOfMemoryError:
The core of the fix requires modifications within the OrderProcessor component of the user-api service. The exact code will depend on the implementation, but the general approach is:

Before (Conceptual - indicative of the problem):

public class OrderProcessor {
    public List<Order> loadAllOrders() {
        // This method is likely fetching ALL orders from the database
        // and holding them in a List<Order> in memory.
        List<Order> allOrders = orderRepository.findAll(); // Problematic
        return allOrders;
    }

    public void processAllOrders() {
        List<Order> ordersToProcess = loadAllOrders();
        for (Order order : ordersToProcess) {
            // Process each order
        }
    }
}

After (Conceptual - implementing pagination/streaming):

public class OrderProcessor {

    // Option 1: Implement pagination for requests that require subsets of orders
    public List<Order> loadOrdersPaginated(int page, int size) {
        // Use Spring Data JPA Pageable or similar mechanism
        Pageable pageable = PageRequest.of(page, size);
        return orderRepository.findAll(pageable).getContent();
    }

    // Option 2: Implement streaming for background processing of all orders
    // This example uses a simple batch approach, but true streaming (e.g., Cursor-based JDBC)
    // would be even more memory efficient for very large datasets.
    public void processAllOrdersStreamedInBatches(int batchSize) {
        int page = 0;
        List<Order> ordersBatch;
        do {
            ordersBatch = loadOrdersPaginated(page, batchSize); // Reuse pagination logic
            for (Order order : ordersBatch) {
                // Process each order in the batch
            }
            // Clear references to allow GC to reclaim memory
            ordersBatch = null;
            page++;
        } while (ordersBatch != null && !ordersBatch.isEmpty());
    }

    // Example of a data access layer change for streaming with Spring Data
    // In OrderRepository.java (or similar interface):
    // @QueryHints(value = @QueryHint(name = org.hibernate.jpa.QueryHints.HINT_FETCH_SIZE, value = "1000"))
    // @Transactional(readOnly = true)
    // Stream<Order> streamAllOrders(); // Requires careful handling of the Stream within a transaction

    // Additionally, review ORM configurations for lazy loading to prevent
    // eagerly loading large related collections.
}

⚡ IMMEDIATE ACTIONS (Do These NOW)

1. Temporarily Increase Cloud Run Memory Allocation: Increase the allocated memory for the user-api Cloud Run service to 2Gi or higher to provide a temporary buffer.

   gcloud run services update user-api \
     --memory 2Gi \
     --region us-central1
   # Note: Adjust '2Gi' to a higher value based on current usage and available resources,
   # but do not excessively increase without addressing the root cause.

2. Restart Service Instances: Force a restart of the user-api service to clear the current memory state and temporarily alleviate the exhausted heap space.
3. Initiate Code Review: Begin an urgent code review of the OrderProcessor component in the user-api service to identify and address the memory leak.

🛡️ PREVENTION

1. Code Review and Refactoring: Thoroughly review the OrderProcessor and related classes for any methods that retrieve or process large datasets without pagination, streaming, or proper memory management. Prioritize refactoring these to use efficient mechanisms.
2. Memory Profiling in Development/Staging: Integrate regular memory profiling (using tools like JVisualVM, YourKit, JProfiler) into the development lifecycle. Specifically, test scenarios that involve processing large numbers of orders to proactively identify and fix memory leaks before they reach production.
3. Implement Pagination and Streaming APIs: Enforce the use of pagination for user-facing endpoints and streaming/batch processing for background tasks when dealing with potentially large collections of data.
4. Optimize ORM Usage: Ensure ORM configurations (e.g., Hibernate, JPA) are optimized for memory. Use lazy loading for collections and associations where appropriate. Consider using DTOs or projections to fetch only necessary data instead of entire entity graphs.
5. Set Appropriate JVM Heap Size: While the root cause is code-related, ensure that the JVM heap size (-Xmx) is adequately configured for the application's typical workload without being excessively large, which can lead to longer GC pauses. For Cloud Run, this is managed by the --memory flag and the JVM will generally adapt.
6. Continuous Monitoring with Heap Metrics: Set up monitoring and alerting for JVM memory usage (heap and non-heap) and garbage collection statistics in Cloud Monitoring. Alerts should trigger on high memory utilization, frequent full GC cycles, and OutOfMemoryError occurrences to catch issues early.
7. Performance Testing with Realistic Data: Conduct load and performance tests using production-like data volumes to simulate real-world conditions and identify memory pressure points.

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