[Monitor OpenTelemetry Exporter] Add Exception Handling to File Name …

…for Telemetry Caching (#28399)

### Packages impacted by this PR
@azure/monitor-opentelemetry-exporter

### Issues associated with this PR
microsoft/ApplicationInsights-node.js#1230

### Describe the problem that is addressed by this PR
Append the process ID to the file name created for holding disk cached
telemetry. This should resolve the issue with multiple Azure Functions
cores attempting to read/write/delete the same file when functions are
scaled to use multiple cores.

Extended this logic outside of Azure Functions so that in any case where
the SDK could be run concurrently we create distinct cache files.

### Command used to generate this PR:**_(Applicable only to SDK release
request PRs)_

### Checklists
- [x] Added impacted package name to the issue description
- [ ] Does this PR needs any fixes in the SDK Generator?** _(If so,
create an Issue in the
[Autorest/typescript](https://github.com/Azure/autorest.typescript)
repository and link it here)_
- [x] Added a changelog (if necessary)

sdk/monitor/monitor-opentelemetry-exporter/CHANGELOG.md

@@ -1,5 +1,15 @@
 # Release History
 
+## 1.0.0-beta.20 ()
+
+### Features Added
+
+### Bugs Fixed
+
+- Added exception handling for reading files to avoid concurrency errors.
+
+### Other Changes
+
 ## 1.0.0-beta.19 (2024-01-23)
 
 ### Features Added

sdk/monitor/monitor-opentelemetry-exporter/src/platform/nodejs/persist/fileSystemHelpers.ts

@@ -1,6 +1,7 @@
 // Copyright (c) Microsoft Corporation.
 // Licensed under the MIT license.
 
+import { diag } from "@opentelemetry/api";
 import * as fs from "fs";
 import * as path from "path";
 import { promisify } from "util";
@@ -15,20 +16,24 @@ const mkdirAsync = promisify(fs.mkdir);
  * @internal
  */
 export const getShallowDirectorySize = async (directory: string): Promise<number> => {
-  // Get the directory listing
-  const files = await readdirAsync(directory);
-
   let totalSize = 0;
+  try {
+    // Get the directory listing
+    const files = await readdirAsync(directory);
 
-  // Query all file sizes
-  for (const file of files) {
-    const fileStats = await statAsync(path.join(directory, file));
-    if (fileStats.isFile()) {
-      totalSize += fileStats.size;
+    // Query all file sizes
+    for (const file of files) {
+      const fileStats = await statAsync(path.join(directory, file));
+      if (fileStats.isFile()) {
+        totalSize += fileStats.size;
+      }
     }
-  }
 
-  return totalSize;
+    return totalSize;
+  } catch (err) {
+    diag.error(`Error getting directory size: ${err}`);
+    return 0;
+  }
 };
 
 /**

sdk/monitor/monitor-opentelemetry-exporter/test/internal/fileSystemPersist.test.ts

@@ -46,7 +46,9 @@ const assertFirstFile = async (tempDir: string, expectation: unknown): Promise<v
 
   // Read the first file in tempDir
   const origFiles = await readdirAsync(tempDir);
-  const files = origFiles.filter((f) => path.basename(f).includes(".ai.json"));
+  const files = origFiles.filter((f) =>
+    path.basename(f).includes(FileSystemPersist.FILENAME_SUFFIX),
+  );
   assert.ok(files.length > 0);
 
   // Assert file matches expectation