Update backend_no_such_file_500_error.md

products/health-care/champva/discovery/backend_no_such_file_500_error.md

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 <h1>Executive Summary: Addressing Intermittent File Processing Failures</h1>
 
-This document details a recurring issue within our application infrastructure that results in intermittent failures during file processing, specifically when renaming or moving temporary files. The error manifests as "No such file or directory @ rb_file_s_rename," indicating that the system attempts to operate on a file that does not exist at the expected location. This issue has been observed to impact
+This document details a recurring issue within our application infrastructure that results in intermittent failures during file processing, specifically when renaming or moving temporary files. The error manifests as "No such file or directory @ rb_file_s_rename," indicating that the system attempts to operate on a file that does not exist at the expected location. This issue has been observed to impact all IVC CHAMPVA and SIMPLE FORMS form submissions leading to some HTML 500 errors after the user clicks on the submit button. While this impacts only 1-2% of submissions, a complete solution is required to ensure system stability and prevent future occurrences.
+
+<h2>Problem Description:</h2>
+
+The core issue is a race condition related to file system operations. A race condition occurs when multiple processes or threads access and manipulate shared resources (in this case, files within the temporary directory) concurrently, and the final outcome depends on the unpredictable order in which these operations execute.
+
+In our specific scenario, the following sequence of events typically leads to the error:
+
+File Creation: A process begins writing data to a temporary file within the system's temporary directory (tmp/).
+File Operation (Rename/Move): Before the first process has fully completed writing to the file, another process attempts to rename or move this file to its final destination.
+Error: Because the file is not yet fully written or its creation is not yet fully committed to the file system, the rename/move operation fails with the "No such file or directory" error.
+This problem is exacerbated by the following factors:
+
+Asynchronous Operations: Our application utilizes asynchronous processes and background jobs to handle certain file operations. This introduces concurrency and increases the likelihood of race conditions.
+Multi-threaded Environment: Our production environment uses a multi-threaded web server (e.g., Puma), allowing multiple requests to be processed concurrently. This further increases the chance of multiple processes accessing the same temporary files simultaneously.
+File System Latency: While generally fast, file system operations can experience brief delays, especially under heavy load. These delays can be sufficient to trigger race conditions if proper synchronization mechanisms are not in place.
+
+