Downloads from the repositories on dl.downloads.com timeout on the UMDS appliance

Products

• VMware vCenter Server

Issue/Introduction

• You have configured UMDS to download vCenter and ESX updates.
• There is a proxy server on the datapath between the UMDS and the repositories on https://dl.broadcom.com.
• You have confirmed using the following command on the UMDS appliance that a proxy is configured:
  /usr/local/vmware-umds/bin/vmware-umds -G
• UMDS log indicates that the download is timing out since the transfer rate is too slow:

error vmware-downloadService[18002] [Originator@6876 sub=httpDownload] [httpDownloadPosix 763] curl_easy_perform() failed: cURL Error: Timeout was reached, Operation too slow. Less than 1 bytes/sec transferred the last 60 seconds
vmware-downloadService[18002] [Originator@6876 sub=httpDownload] [httpDownloadPosix 763] [backtrace begin] product: VMware vSphere Update Manager Download Service, version:
 8.0.3, build: build-24022515, tag: vmware-downloadService, cpu: x86_64, os: linux, buildType: release
--> backtrace[00] libvmacore.so[0x00530335]
--> backtrace[01] libvmacore.so[0x0042082A]: Vmacore::System::Stacktrace::CaptureFullWork(unsigned int)
--> backtrace[02] libvmacore.so[0x00433009]: Vmacore::System::SystemFactory::CreateBacktrace(Vmacore::Ref<Vmacore::System::Backtrace>&)
--> backtrace[03] libvci-vcIntegrity.so[0x00E0A91F]
--> backtrace[04] libvci-vcIntegrity.so[0x00E0AD57]

Environment

VMware vCenter Server

Cause

• Filters enabled on the Proxy between the UMDS appliance and the download repositories are slowing down the transfer rate.
• It has been found that SSL/TLS interception can add significant latency to the downloads if enabled on the proxy.

Resolution

• Solution is to work with your network team to identify and disable possible sources of filtering, which might be introducing latency from the download URL.

Additional Information

• Proxy SSL interception is a technique where an intermediary device, like a proxy or firewall, decrypts secure (SSL/TLS) traffic to inspect it for threats or policy violations before re-encrypting it and sending it to its original destination.
• Connectivity and transfer rates from https://dl.broadcom.com can be tested on the UMDS appliance manually using a command like below:
  
  curl -x -v --proxy "https://<proxy url>:<proxy port number>" --proxy-user <username>:<password> "https://dl.broadcom.com/<download tokenID>/PROD/COMP/ESX_HOST/main/esx/vmw/vmw-ESXi-8.0.2-metadata.zip" --output /tmp/test.zip