【Azure 應用服務】Azure Function (PowerShell) 執行時報錯 "out of memory"

問題描述

在Azure Function App服務中，建立一個PowerShell腳本的函數，遇見了OOM(Out Of Memory)的異常報錯：

2022-01-10T07:44:37  Welcome, you are now connected to log-streaming service. The default timeout is 2 hours. Change the timeout with the App Setting SCM_LOGSTREAM_TIMEOUT (in seconds).
2022-01-10T07:44:39.879 [Information] Executing 'Functions.BlobTrigger1' (Reason='New blob detected: Exception of type 'System.OutOfMemoryException' was thrown.', Id=xxxxxxxx-xxxxxxxx-xxxxxxxx-xxxxxxxx-xxxxxxxx)
2022-01-10T07:44:39.883 [Information] Trigger Details: MessageId: xxxxxxxx-xxxxxxxx-xxxxxxxx-xxxxxxxx-xxxxxxxx, DequeueCount: 5, InsertionTime: 2022-01-10T07:41:29.000+00:00, BlobCreated: 2022-01-10T07:41:28.000+00:00, BlobLastModified: 2022-01-10T07:41:28.000+00:00
2022-01-10T07:44:39.911 [Error] Executed 'Functions.BlobTrigger1' (Failed, Id=xxxxxxxx-xxxxxxxx-xxxxxxxx-xxxxxxxx-xxxxxxxx, Duration=11084ms)Exception of type 'System.OutOfMemoryException' was thrown.      

運作的腳本就是執行 AzCopy Copy 檔案

param([byte[]] $InputBlob, $TriggerMetadata)
Write-Host "PowerShell Blob trigger function Processed blob! Name: $($TriggerMetadata.Name) Size: $($InputBlob.Length) bytes"

$AzcoypFile = "azcopy.exe"
$AzCopyExists = Test-Path $AzcoypFile
Write-Host "AzCopy exists:" $AzCopyExists
# Download AzCopy.zip and unzip if it doesn't exist
If ($AzCopyExists -eq $False)
{
    Write-Host "AzCopy not found. Downloading..."
    
    #Download AzCopy
    Invoke-WebRequest -Uri "https://aka.ms/downloadazcopy-v10-windows" -OutFile AzCopy.zip -UseBasicParsing

    #unzip azcopy
    write-host "unzip azcopy.zip"
    Expand-Archive ./AzCopy.zip ./AzCopy -Force
    # Copy AzCopy to current dir
    Get-ChildItem ./AzCopy/*/azcopy.exe | Copy-Item -Destination "./AzCopy.exe"
}

# Run AzCopy from source blob to destination blob  (Single Direction)
Write-Host "copy new content"
./azcopy.exe sync "https://xxxxxxxxxxxxxxxxx..............      

問題分析

因為預設建立Azure Funciton Windows環境時，平台預設使用的是32 Bit，是以存在記憶體上限問題。是以最快方法就是檢視平台的位數，修改為64 Bit。讓系統有更多的記憶體空間可用。

參考資料

I see the message "Worker Process requested recycle due to 'Percent Memory' limit." How do I address this issue? 

https://docs.microsoft.com/en-us/azure/app-service/faq-availability-performance-application-issues#i-see-the-message--worker-process-requested-recycle-due-to--percent-memory--limit---how-do-i-address-this-issue-

The maximum available amount of memory for a 32-bit process (even on a 64-bit operating system) is 2 GB. By default, the worker process is set to 32-bit in App Service (for compatibility with legacy web applications).

Consider switching to 64-bit processes so you can take advantage of the additional memory available in your Web Worker role. This triggers a web app restart, so schedule accordingly.

Also note that a 64-bit environment requires a Basic or Standard service plan. Free and Shared plans always run in a 32-bit environment.

當在複雜的環境中面臨問題，格物之道需：濁而靜之徐清，安以動之徐生。 雲中，恰是如此!