Role environment . FAILED TO INITIALIZE - azure-web-app-service

Question

I have a number of Azure Web Sites running on single-instance, Standard S2 tiers (each site on it's own instance). The sites are in different regions and they run completely different and independent code. I have noticed that if I view the eventlog.xml file on any of my sites, I see a number of Role environment . FAILED TO INITIALIZE events showing up. Here is an extract from the file:
<Event>
<System>
<Provider Name="Windows Azure Runtime 2.5.0.0"/>
<EventID>1013</EventID>
<Level>0</Level>
<Task>0</Task>
<Keywords>Keywords</Keywords>
<TimeCreated SystemTime="2015-05-06T07:07:35Z"/>
<EventRecordID>976923406</EventRecordID>
<Channel>Application</Channel>
<Computer>RD000XXXXXE</Computer>
<Security/>
</System>
<EventData>
<Data>4008</Data>
<Data>w3wp</Data>
<Data>Role environment . INITIALIZING</Data>
</EventData>
</Event>
<Event>
<System>
<Provider Name="Windows Azure Runtime 2.5.0.0"/>
<EventID>1013</EventID>
<Level>0</Level>
<Task>0</Task>
<Keywords>Keywords</Keywords>
<TimeCreated SystemTime="2015-05-06T07:07:36Z"/>
<EventRecordID>976923937</EventRecordID>
<Channel>Application</Channel>
<Computer>RD000XXXXXE</Computer>
<Security/>
</System>
<EventData>
<Data>4008</Data>
<Data>w3wp</Data>
<Data>Role environment . INITIALED RETURNED. HResult=-2147024891</Data>
</EventData>
</Event>
<Event>
<System>
<Provider Name="Windows Azure Runtime 2.5.0.0"/>
<EventID>1015</EventID>
<Level>3</Level>
<Task>0</Task>
<Keywords>Keywords</Keywords>
<TimeCreated SystemTime="2015-05-06T07:07:36Z"/>
<EventRecordID>976924062</EventRecordID>
<Channel>Application</Channel>
<Computer>RD000XXXXXE</Computer>
<Security/>
</System>
<EventData>
<Data>4008</Data>
<Data>w3wp</Data>
<Data>Role environment . FAILED TO INITIALIZE. hr: -2147024891</Data>
</EventData>
</Event>
I have also noticed that these events coincide with a brief outage of the site (just a minute or two). These events seem to be random. Sometimes there can be 20 events in an hour. Other times it can go for days without a single event.
I am trying to understand what is causing these events and how (or if) I can prevent them. I would prefer not to have my sites go down at all. I can probably mitigate the issue by having multiple instances for each site but even so, I would at least like to have a good answer as to what is going on here.
Note: these sites are deployed to Azure Websites, not Cloud Services (i.e. not Web or Worker Roles).

Answer 1

These events are written when you reference Azure Diagnostics in your web app. It is not recommended to use this in case of web app. It makes sense to use it in cloud services, but not in case of web apps.
This can affect the application sometimes.