vSphere plugin exceeds the memory limit set in the extensibility performance targets for vSphere 7.0

Products

• VMware vCenter Server

Issue/Introduction

The purpose of this article is to make VMware customers and partners aware of performance targets for vSphere plugins in vSphere 7.0, the impact of running a plugin which does not meet the performance targets and to outline the steps to work around the resulting memory issue if it occurs.

Symptoms:
You experience one or more of these symptoms:

• The vSphere Client either randomly crashes or becomes unresponsive due to a supposed memory leak.
• You are unable to load inventory at times.
• You see this error message in vSphere Client logs:

Exception handled while processing request for /ui/cache/h5-namespace-init

Environment

VMware vCenter Server 7.0.x

Cause

vSphere Client plugin exceeds the memory consumption limits set for vSphere 7.0. 
Performance scalability targets for vSphere plugins are set in order to make sure the performance of vSphere client is not hampered by any plugin. The targets can be updated for each major vSphere release if necessary, reflecting the technological/architectural changes.
The goal is to prevent user experience deterioration by interface latency derived from the installation of plugins which are not performing within the specified limits. 
The targets indicate the supported limits for memory consumption by installed plugins.

The limits in vSphere 7.0 are: 

• Plugin static memory overhead: 25 MB
• Supported vCenter server instances in ELM: 15
• Supported concurrent users: 100
• Maximum supported plugin memory increase per user per vCenter server: 50 KB
• Maximum supported plugins (abiding by the performance targets): 5
• Maximum allowed memory per plugin: 100 MB
• Total VCSA/vSphere Client memory required for plugins: 500MB.

Resolution

All partner plugins and third-party extensions of vSphere 7.0 must meet the set performance targets.

Workaround:
If the plugins installed are deemed too heavy for the heap size that the vsphere-ui process has allocated,  the memory dumps shows a lot of memory allocated on transport (jaxb/xml deserialization) for the plugins. 

You can work around this issue by applying the steps below to increase memory heap allocated to UI on the CloudVM:

1. Increase the size of allocated memory:  cloudvm-ram-size --setCustom 1500 vsphere-ui
2. Restart the vSphere Client (vsphere-ui process): service-control --restart vsphere-ui

This change increases the heap allocated to the vsphere-ui process to 1500 MB. Please be aware the value of 1500 MB is expected to be sufficient for the majority of cases, however it is possible that a higher memory size is required for a particularly heavy plugin.