I have a MAUI App that connects to a Hosting with ASP .NET. On it, I have some ASP services and its user a Sqlite database.
I have a service that reads a list of words filtering by a type of word. When I try to get the service, the 2 o 3 first times I do not receive anything, I need to call de get 4 o 5 times to receive the database information from the server. SO, I think that is a problem of the hosting. Correct?
This is my code:
public async Task<List<Words>> GetWordsContain(string word)
{
string url = "http://----------------.com/words/GetWordsContain/" + word;
Uri uri = new Uri(string.Format(url, string.Empty));
try
{
HttpResponseMessage responseMessage = await _client.GetAsync(uri);
if (responseMessage.IsSuccessStatusCode)
{
string content = responseMessage.Content.ReadAsStringAsync().Result;
Records = JsonConvert.DeserializeObject<List<Words>>(content);
responseMessage.Dispose();
return Records;
}
else
{
return null;
}
}
catch (Exception ex)
{
return null;
}
}
The HttpResponseMessage.RequestMessage is
{Method: GET, RequestUri: 'http://xxxxxxxxxx/words/GetWordsContain/hello', Version: 1.1, Content: , Headers:
{
}}
Related
So I have to API's running on Kubernetes. One has a controller function as such:
string filePath = "/blobs/data/runsession/" + folderName;
if (!Directory.Exists(filePath))
return null;
var tempFile = Path.Combine(Path.GetTempPath(), guid.ToString());
logger.Info("GetTempPath()" + Path.GetTempPath());
logger.Info("Temp path is: " + tempFile);
ZipFile.CreateFromDirectory(filePath, (tempFile + ".zip"));
byte[] fileBytes = File.ReadAllBytes(tempFile + ".zip");
HelpMethods.GetNetworkTimeStamp("Stop", 2);
return fileBytes;
This controller method works fine and when I call it from postman it returns a file.
Now in the other API I want to call this function from one of my service classes as such:
public async Task<byte[]> DownloadRunSession(string foldername)
{
try
{
var request = new RestRequest($"blob/{foldername}")
{
Timeout = -1,
};
var response = await client.ExecuteGetAsync(request);
if (!response.IsSuccessful)
{
Console.WriteLine("File download failed");
Console.WriteLine(response.Content.ToString());
return null;
}
return response.RawBytes;
}catch(Exception e)
{
Console.WriteLine(e.Message);
Console.WriteLine(e.StackTrace);
return null;
}
Now the server logs on the API that sends the file Give me a status 200 but says "the application aborted the connection", and the API that is supposed to receive the file gets no response and the response variable is always "null".
Any one that has had a similar dilemma and knows how to solve it?
This is the exact exception in the error logs.
I have a requirement where I should be creating a set of service calls and wait till all of them are completed successfully before moving on to do a different set of service calls.
I have two services Service1 and Service2.
There are 2 instances of Service2 in 2 different servers and we have set up an F5(Load Balancer) to distribute the load evenly.
Let's say I have 10 service calls to be made from Service1 to Service2 at a time and F5 will share those 10 calls among the 2 servers. i.e. 5 Calls to Service2 of each server.
But I observed that if any one of those 10calls is taking lot of time to complete the work it should do(The work to be done in Service2 has some heavy lifting) then i get a socket exception thrown and entire process gets stopped.
However when I dont use the F5 load balancer and just use 1 instance of the Service2. Then however long the process takes for any of those 10 calls it doesn't throw any exception.
I am not sure if this is an issue with F5 configuration or with the way connections are made with the F5 from .Net code.
Please go through the below code to get some idea of what i am trying to do and let me know if any code change would help me resolve it.
for (int i=0 ; i< ReqList.Count;i++)
{
maxTasks++;
ClassA reqList = new ClassA();
reqList = ReqList[i];
List<ClassA> recsByReq = recs.Where(x => x.ReqId == reqList.ReqtId).ToList();
ClassC service2Input = new ClassC();
service2Input.DetaiList = listofRecs;
service2Input.RecList = recsByReq;
taskList.Add(_service2.Service2MethodCall(service2Input, service2Resource));
if(maxTasks == 10 || ReqList.Count == 10 || i==ReqList.Count-1)
{
Task.WaitAll(taskList.ToArray(),-1);
maxTasks = 0;
taskList.Clear();
}
}
The Service2MethodCall is where I am creating a HttpClient to make connections with the 2nd service i.e. Service2,
public class Service2: IService2 {
private ServiceClient GetService2(string resource)
{
return new ServiceClient(_service2BaseUrl, TimeSpan.FromMinutes(60))
{
Resource = resource,
};
}
public async Task Service2MethodCall(ClassC service2Input, string resource)
{
try
{
var client = GetService2(resource);
await client.PostAsync(JsonConvert.SerializeObject(service2Input).ToString());
}
catch (Exception ex)
{
throw new Exception("The Service encountered an error during the Service2 call for Req ID : " +
service2Input.RecsList.Find(x => x.ReqId != "").ReqId.ToString(), ex);
}
}
}
The PostAsync() method creates a new HttpClient with HttpClientHandler object for each of the call.
public async Task PostAsync(object data) {
using(var httpClientHandler = new HttpClientHandler()) {
httpClientHandler.ServerCertificateCustomValidationCallback = (message, cert, chain, sslPolicyErrors) => {
if (sslPolicyErrors == SslPolicyErrors.None) {
return true; //Is valid
}
if (cert.GetCertHashString().ToUpper() == _acceptedThumbprint.ToUpper()) {
return true;
}
return false;
};
using(var client = new HttpClient(httpClientHandler)) {
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(ResponseFormatter.MediaType);
client.Timeout = Timeout.InfiniteTimeSpan;
Uri uri = BuildUri();
if (!String.IsNullOrWhiteSpace(SignatureKey)) {
client.DefaultRequestHeaders.TryAddWithoutValidation("Authorization",
RequestFormatter.GenerateAuthHeaderEncodedUserSignature(uri, AuthUserName, SignatureKey, data));
}
//_logger.WriteUsage(client.BaseAddress.ToString());
HttpResponseMessage response = await RequestFormatter.PostAsync(client, uri, data);
string content = await response.Content.ReadAsStringAsync();
try {
response.EnsureSuccessStatusCode();
}#
pragma warning disable CS0168 // The variable 'rex' is declared but never used
catch (HttpRequestException rex)# pragma warning restore CS0168 // The variable 'rex' is declared but never used
{
//_logger.WriteUsage("Response for POST to: {0} did not yield a successful status code. Message: {1}" + uri.ToString() + content);
throw new ApiHttpException(response.StatusCode, content);
}
}
}
}
Is there some thing I can do within the code to avoid this situation once and for all?
I have the following method in Xamarin that makes an API call that returns a list of Items. When I start Visual Studio and run it returns a string of JSON with the information I expect it to. However when I run it several times and more often than not it hits the string returnedJson = await client.GetStringAsync line then just breaks out of the method, returning nothing.
I dont think its related to restarting Visual Studio, because sometimes after it not working several times it will work once again then stop again.
public async Task<IEnumerable<ItemModel>> GetItemsAsync(bool forceRefresh = false)
{
var baseAddr = new Uri("https://www.domain.co.uk");
var client = new HttpClient
{
BaseAddress = baseAddr
};
client.DefaultRequestHeaders.Authorization = new System.Net.Http.Headers.AuthenticationHeaderValue("Bearer", Settings.ApiToken);
// NOW PROTECTED
try
{
string returnedJson = await client.GetStringAsync("/api/Items/Index");
var convert = JsonConvert.DeserializeObject<List<ItemModel>>(returnedJson);
return convert;
}
catch (Exception ex)
{
return null;
}
return null;
}
The WebAPI method -
[Authorize]
[HttpGet("[action]")]
public async Task<List<ItemModel>> Index()
{
return await itemService.Get();
}
I'm using the following code in a Xamarin Forms app:
HttpResponseMessage response = null;
try
{
HttpContent content = new StringContent(JsonConvert.SerializeObject(register), Encoding.UTF8, "application/json");
response = await client.InvokeApiAsync("register", content, HttpMethod.Post, null, null);
if (!response.IsSuccessStatusCode)
{
string error = await response.Content.ReadAsStringAsync();
var def = new { Message = "" };
var errorMessage = JsonConvert.DeserializeAnonymousType(error, def);
return KloverResult.BuildError(true, errorMessage.Message);
}
}
catch (MobileServiceInvalidOperationException e)
{
if (e.Response.StatusCode == System.Net.HttpStatusCode.InternalServerError)
{
string error = await e.Response.Content.ReadAsStringAsync();
var def = new { Message = "" };
var errorMessage = JsonConvert.DeserializeAnonymousType(error, def);
return KloverResult.BuildError(true, errorMessage.Message);
}
else
{
return KloverResult.BuildError(false, "Invalid username or password");
}
}
The issue that I'm having is when a MobileServiceInvalidOperationException is thrown as a result of a 500. When I try to read the content of the response (e.Response.Content) it's null. When I call the same API using Restlet I get the following response:
{
"Message": "Name jblogs is already taken."
}
This is what I expect to be in my error variable, however it's null.
My question is, should I be able to read the Content of the Response? If so, do I need to do some more setup on the client/server? The API being called is returning the error form a webapi using:
Request.CreateErrorResponse(HttpStatusCode.InternalServerError, "Name jblogs is already taken.");
Any help would be appreciated.
A 500 response means that the server crashed. It's likely that there was no content in that case.
If your API is returning status=500, then it is doing the wrong thing. What you should be doing is returning a status in the 400 series - 409 (conflict) seems appropriate to me.
If your API is not returning status=500 deliberately, then the server crashed and you don't get content.
According to your description, I built my Mobile App application with a custom WebApi endpoint to test this issue. Based on my test, I leverage Microsoft.Azure.Mobile.Client 3.1.0 to invoke custom WebApi, I could retrieve the content by Response.Content.ReadAsStringAsync() when the response status is 409 or 500 and so on. Here are my code snippet, you could refer to them:
WebApi
[MobileAppController]
public class ValuesController : ApiController
{
public async Task<HttpResponseMessage> Get()
{
await Task.Delay(TimeSpan.FromSeconds(2));
return Request.CreateErrorResponse(HttpStatusCode.Conflict, "Name jblogs is already taken.");
}
}
Client App
try
{
MobileServiceClient client = new MobileServiceClient("https://bruce-chen-002.azurewebsites.net/");
var response = await client.InvokeApiAsync("/api/values", HttpMethod.Get, null);
}
catch (MobileServiceInvalidOperationException e)
{
if (e.Response.StatusCode == System.Net.HttpStatusCode.InternalServerError)
{
string error = await e.Response.Content.ReadAsStringAsync();
}
}
Result
I have strange problem with my Game written in Unity (Mono). I have login functionality and then, after successfull login i'm sending some kind of keep-alive requests to ensure token is updated (I'm sending it every 30s).
The problem is, that after some time (sometimes it's 1 hour, sometimes 2.5 hours) all my requests have timeout status.
To be sure about my connection status I made some checks in code: I'm making simple GET to http://google.com and to main website of my API (not an API call. Just website GET). When I got timeout on API next time i figured out that:
After 1 timeout I have it always. Restarting application helps
I'm getting timeouts on API call and on GET request for base API website
Google is still responding with status 200 (no timeouts here)
Implementation:
On beginning i've been using RestSharp to handle requests, but the problem occured and there was a decision to throw RestSharp away and now we're using classic WebClient
class BetterWebClient : WebClient
{
private WebRequest _Request = null;
public TimeSpan? Timeout { get; set; }
protected override WebRequest GetWebRequest(Uri address)
{
this._Request = base.GetWebRequest(address);
if ( Timeout.HasValue )
{
_Request.Timeout = (int)Timeout.Value.TotalMilliseconds;
}
else
{
_Request.Timeout = 10*1000; //10s
}
if (this._Request is HttpWebRequest)
{
((HttpWebRequest)this._Request).AllowAutoRedirect = true;
}
return this._Request;
}
}
My HandleRequest function (which also calls Google and API website) looks like this:
public static void HandleRequest<TR>(string url, RestResponse<TR> executeGetRequest) where TR : new()
{
using (BetterWebClient w = new BetterWebClient() {Timeout = TimeSpan.FromSeconds(2)})
{
try
{
string downloadString = w.DownloadString("http://www.google.com");
Debug.Log("Google request: OK");
}
catch ( Exception )
{
Debug.LogError("Google request failed");
}
try
{
string downloadString = w.DownloadString("myAPIwebsite");
Debug.Log("WorldOfRescue.com request: OK");
}
catch ( Exception )
{
Debug.LogError("WorldOfRescue.com request failed");
}
}
var client = new BetterWebClient() {Timeout = TimeSpan.FromSeconds(5)};
client.Headers.Add("Accept", "application/json");
client.Headers.Add("Content-Type", "application/json");
try
{
string downloadString = client.DownloadString(url);
Debug.Log("Request for "+url+ " completed. Response: " + downloadString);
}
catch ( WebException e )
{
Debug.Log(e.Status);
throw;
}
catch ( Exception e )
{
Debug.Log(e.ToString());
throw;
}
finally
{
client.Dispose();
}
}
Do you have any idea why it happens? It looks like something is blocking me to send request to specific website, but in same time other website is working fine.