Http failure response Unknown Error occurs in VMware Cloud Director

Products

• VMware Live Recovery

Issue/Introduction

• While interacting with the user interface for VMware Cloud Director (VCD), an error similar to the following occurs:
  
  Http failure response for https://######.#####.###/... 0 Unknown Error
  
  
• One or more VMware Cloud Director Availability (VCDA) plugins are installed and functioning in the VCD user interface.
• When accessing a VCDA plugin, the interface takes time to load and eventually indicates that the service is inaccessible.
• In the web developer tools of the Chrome browser, multiple calls to data-engine are in a pending state and there are ERR_INSUFFICIENT_RESOURCES errors for the most recent calls to VCD and VCDA.

Environment

VMware Cloud Director 10.6.x

Cause

Attempts to reach the VCDA public endpoint are not completing and are not being closed, so pending connections to the endpoint are accumulating in the browser and eventually consuming the memory resources.

Resolution

There are multiple approaches to addressing this issue:

• Enable access to the VCDA public endpoint(s) from the client device.
• Explicitly block the VCDA domains in the browser web developer tools.
• Remove VCDA.
• Review the firewall and, if they connections are being silently dropped, change the rule to deny so that the attempts close more quickly.
• Point the FQDNs to an address that will reject the connection and fail immediately on the client device.