Asynchronous calls using Async and Await - azure

Question

In .Net framework 4.5 async and await keywords are introduced to do async calls.
I have used them in web applications too. I came to know that it can also be done using doing delegates.
Below are my sample snippet showing how async calls are done
Public void binddata()
{
certificate = HelperMethods.GetStoreCertifcate(Thumbprint);
ListHostedServices(SubscriptionId, certificate, Version);
hostedservicesview.ActiveViewIndex = 0;
ListStorageAccounts(SubscriptionId, certificate, Version);
}
public async void ListHostedServices(string subscriptionId, X509Certificate2 certificate, string version)
{
string hittingUri = String.Format("https://management.core.windows.net/{0}/" + "services/hostedservices",SubscriptionId);
XmlDocument responsebody= await HelperMethods.GetXmlDocument(hittingUri, certificate, version);
if (responsebody != null)
{
var result = responsebody.GetElementsByTagName("HostedServiceProperties");
hostedservices = new DataTable();
hostedservices.Columns.Add("Url");
hostedservices.Columns.Add("ServiceName");
hostedservices.Columns.Add("Location");
hostedservices.Columns.Add("Label");
hostedservices.Columns.Add("Status");
hostedservices.Columns.Add("DateCreated");
hostedservices.Columns.Add("DateLastModified");
foreach (XmlNode hsnode in result)
{
DataRow hsrow = hostedservices.NewRow();
hsrow["Url"] = hsnode.ParentNode.ChildNodes.OfType<XmlElement>().Where(x => x.Name == "Url").Any() ?
hsnode.ParentNode.ChildNodes.OfType<XmlElement>().Where(x => x.Name == "Url").First().InnerText : string.Empty;
hsrow["ServiceName"] = hsnode.ParentNode.ChildNodes.OfType<XmlElement>().Where(x => x.Name == "ServiceName").Any() ?
hsnode.ParentNode.ChildNodes.OfType<XmlElement>().Where(x => x.Name == "ServiceName").First().InnerText : string.Empty;
hsrow["Location"] = hsnode.ChildNodes.OfType<XmlElement>().Where(x => x.Name == "Location").Any() ?
hsnode.ChildNodes.OfType<XmlElement>().Where(x => x.Name == "Location").First().InnerText : string.Empty;
// IF location is empty, it means affinity group is returned, Pull location from affinity group
if (String.IsNullOrEmpty(hsrow["Location"].ToString()))
{
string affnitygroup = hsnode.ChildNodes.OfType<XmlElement>().Where(x => x.Name == "AffinityGroup").Any() ?
hsnode.ChildNodes.OfType<XmlElement>().Where(x => x.Name == "AffinityGroup").First().InnerText : string.Empty;
certificate = HelperMethods.GetStoreCertifcate(Thumbprint);
hsrow["Location"] = await HelperMethods.GetAffinityGroupLocation(subscriptionId, certificate, Version, affnitygroup);
}
hsrow["Label"] = hsnode.ChildNodes.OfType<XmlElement>().Where(x => x.Name == "Label").Any() ?
hsnode.ChildNodes.OfType<XmlElement>().Where(x => x.Name == "Label").First().InnerText : string.Empty;
hsrow["Status"] = hsnode.ChildNodes.OfType<XmlElement>().Where(x => x.Name == "Status").Any() ?
hsnode.ChildNodes.OfType<XmlElement>().Where(x => x.Name == "Status").First().InnerText : string.Empty;
hsrow["DateCreated"] = hsnode.ChildNodes.OfType<XmlElement>().Where(x => x.Name == "DateCreated").Any() ?
hsnode.ChildNodes.OfType<XmlElement>().Where(x => x.Name == "DateCreated").First().InnerText : string.Empty;
hsrow["DateLastModified"] = hsnode.ChildNodes.OfType<XmlElement>().Where(x => x.Name == "DateLastModified").Any() ?
hsnode.ChildNodes.OfType<XmlElement>().Where(x => x.Name == "DateLastModified").First().InnerText : string.Empty;
hostedservices.Rows.Add(hsrow);
}
lbl_count.Text = hostedservices.Rows.Count.ToString();
HostedServicesList.DataSource = hostedservices;
HostedServicesList.DataBind();
}
else
{
}
}
**XmlDocument responsebody= await HelperMethods.GetXmlDocument(hittingUri, certificate, version);**
The method definition is as follows
public static async Task<XmlDocument> GetXmlDocument(string hittingUrl, X509Certificate2 certificate, string Version)
{
HttpWebRequest request;
XmlDocument responsebody = new XmlDocument();
// string hittingUri = "https://management.core.windows.net/{0}/" + "services/hostedservices";
Uri uri = new Uri(hittingUrl);
request = (HttpWebRequest)HttpWebRequest.Create(uri);
request.Method = "GET";
request.Headers.Add("x-ms-version", Version);
request.ClientCertificates.Add(certificate);
request.ContentType = "application/xml";
HttpWebResponse webresponse= null;
try
{
webresponse = (HttpWebResponse)await request.GetResponseAsync();
}
catch (Exception)
{
}
HttpStatusCode statuscode = webresponse.StatusCode;
if (webresponse.ContentLength > 0)
{
using (XmlReader reader =XmlReader.Create(webresponse.GetResponseStream()))
{
responsebody.Load(reader);
}
}
if (statuscode.Equals(HttpStatusCode.OK))
{
return responsebody;
}
else
{
return null;
}
}
Similarly above 2 methods also have same kind of listing.
Its taking me approximately 12-15 seconds to retrieve data of 11+19+6 records.
Could you guys help me in optimizing this code so that it will be much faster.

Answer 1

First you need to profile your code to see where exactly are you loosing your time. If the GetXMLDocument is taking up most of the time then it may be that the server is not as responsive
Outside of that my guess would be that your foreach loop is taking the most amount of time because you are essentially searching through all the elements in each statement in here.
Another way of doing this could be
Dictionary<string, string> nvpairsForColumns = new Dictionary { "Url", String.Empty }; // add all valid column headers here
foreach(var xelement in hsnode.ParentNode.ChildNodes.OfType<XmlElement>)
{
if(nvparisForColumns.ContainsKey(xelement.Name)
&& String.IsNullOrEmpty(nvpairsForColumns[xlement.Name])) // assumption String.Empty is not a valid entry else keep another Dictionary<string,bool> to tag when done with first
{
nvpairsForColumns[xelement.Name] = xelement.InnerText;
}
}