Azure Functions: Application freezes - “UnableToLo

问题:

I have an Azure Functions application which once in a while "freezes" and stops processing messages and timed events.

When this happens I do not see much in the logs (AppInsight), except for the following error message telling me "UnableToLoadExpressionAssembly":

timestamp [UTC]: 2018-02-13T09:18:19.609Z
message: UnableToLoadExpressionAssembly
severityLevel: 3
customDimensions:
    LogLevel: Error
    prop__{OriginalFormat}: UnableToLoadExpressionAssembly
    Category: Host.Startup
client_Type: PC
client_IP: 0.0.0.0
cloud_RoleName: (...)
cloud_RoleInstance: (...)
appId: (...)
appName: (...)
iKey: (...)
sdkVersion: azurefunctions: 1.0.11510.0
itemId: e5362c17-109e-11e8-93fc-0f54eb87135a
itemType: trace
itemCount: 1

What is going wrong here?

回答1:

The issue is caused by the deployment mechanism used not initiating a trigger synchronization, which prevents the infrastructure from activating the Function App when needed.

Deployments using the CI/CD integration, Visual Studio, MSDeploy or ZIP deploy will trigger that synchronization and ensure your function app is activated when needed.