public async Task <TimeSpan> UpdateServiceHelth()
{
// Read saved service providers from the DB
List <ServiceProvider> serviceProviders = await serviceProviderRepository.GetAll();
// Check network connectivity status
ServiceStatusResult updateResult = await networkService.CheckTcpConnection(serviceProviders);
// write new status to the DB
Task updateServiceProviderTask = serviceProviderRepository.Upsert(updateResult.ServiceProviders);
// send mail notifications
Task <TimeSpan> sendMailTask = SendNotifications(updateResult);
// DB update, email notification and polling freaquency read can happen asynchronusly
// Let the DB query run asynchronously while above two operations runs
Task <TimeSpan> pollingFreaquencyTask = serviceProviderRepository.GetMaximumPollingFreaquency();
// wait for DB update and notifications to complete
await updateServiceProviderTask;
TimeSpan minimumGracePeriod = await sendMailTask;
// wait for the query result. This should be already completed
TimeSpan pollingFreaquency = await pollingFreaquencyTask;
// Next update cycle will be initialized based on the minimum value between polling frequency and minimum grace period of failed services.
// From the NetworkService class correct polling frequency will be checked and skipped unnecessary network checks
TimeSpan nextUpdateFrequency = minimumGracePeriod < pollingFreaquency ? minimumGracePeriod : pollingFreaquency;
return(nextUpdateFrequency);
}
public async Task AddSubscription(string email, string host, int port, int pollingFreaquency, int gracePeriod)
{
ServiceProvider serviceProvider = await serviceProviderRepository.GetByHostAndPort(host, port);
TimeSpan requestedPollingFrequency = GetTimeSpan(pollingFreaquency);
// If service provider is not found add new one
serviceProvider = serviceProvider == null ? new ServiceProvider()
{
Host = host, Port = port, PollingFrequency = requestedPollingFrequency
} : serviceProvider;
// If service provider is existing always update the service provider with the maximum polling freaquency
serviceProvider.PollingFrequency = serviceProvider.PollingFrequency > requestedPollingFrequency? requestedPollingFrequency : serviceProvider.PollingFrequency;
List <ServiceProvider> serviceProvidersToUpdate = new List <ServiceProvider>();
serviceProvidersToUpdate.Add(serviceProvider);
// Update database with service provider details
await serviceProviderRepository.Upsert(serviceProvidersToUpdate);
// Refreash service provider after inserting to map the subscription for user
if (serviceProvider.Id == 0)
{
serviceProvider = await serviceProviderRepository.GetByHostAndPort(host, port);
}
// if service provider not found in the user, update the subscription
User user = await userRepository.GetUserByEmail(email);
if (user.Subscriptions.Where(s => s.Service.Id == serviceProvider.Id).Count() == 0)
{
ServiceSubscription serviceSubscription = new ServiceSubscription()
{
Service = serviceProvider, PollingFrequency = requestedPollingFrequency, GracePeriod = GetTimeSpan(gracePeriod)
};
user.Subscriptions.Add(serviceSubscription);
List <User> usersToUpdate = new List <User>();
usersToUpdate.Add(user);
await userRepository.Upsert(usersToUpdate);
}
}