Azure Classic VM Memory utilization issue: Webhost failed to process a request.
It's quite interesting that the customers are still using classic VM (ASM) to host their web services. I recently working with the customer on the higher memory utilization issue one of their production workload and they were getting below error.
Webhost failed to process a request.
Sender Information: System.ServiceModel.ServiceHostingEnvironment+HostingManager/12547953
Process Name: w3wp
Process ID: 12500
What could be the cause?
+ Generally, it can be due to that server is not configured with HA and might be the server is not handle the load due to current configuration
We investigated the issue and found that the server was not able to handle the traffic at peak time and it was throughing memory is less than 5% of total memory.
We found that the server was not enabled with availability sets and it's quite difficult to enable the server with AS once it got setup with the services.
Exception: System.ServiceModel.ServiceActivationException: The service '/*****.WcfService/WebPageCapture.svc' cannot be activated due to an exception during compilation. The exception message is: Memory gates checking failed because the free memory (146046976 bytes) is less than 5% of total memory. As a result, the service will not be available for incoming requests. To resolve this, either reduce the load on the machine or adjust the value of minFreeMemoryPercentageToActivateService on the serviceHostingEnvironment config element.. ---> System.InsufficientMemoryException: Memory gates checking failed because the free memory (146046976 bytes) is less than 5% of total memory. As a result, the service will not be available for incoming requests.
Definitely, you do not get much time to go deeper and start the process to migrating the existing services to new setup using HA. The best way to tackle certain situation is by resizing the VM size. This is one of the great benefits of Azure VMs is the ability to change the size of your VM based on the needs for CPU, Network or disk performance.