Running fine on RHEL 8 about half an hour then got "The LDAP server is unavailable." exception.

[caotoulei]

Here is the related code in my .net core API project Program.cs file.
...
builder.Services.AddAuthentication(NegotiateDefaults.AuthenticationScheme)
.AddNegotiate(options =>
{
if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
{
options.EnableLdap(settings =>
{
settings.Domain = "xxxxx.COM";
var ldapConnection = new LdapConnection(
new LdapDirectoryIdentifier("ldap ip", 389, true, false),
new NetworkCredential(ApplicationData.srv_username, ApplicationData.srv_password),
AuthType.Basic);
ldapConnection.SessionOptions.ReferralChasing = ReferralChasingOptions.None;

             ldapConnection.AutoBind = true;

             settings.LdapConnection = ldapConnection;

         });
     }
 });

...
It runs fine on RHEL 8 Apache for about half an hour, and all the POST/GET requests to get responses right. Then, all the requests throw exceptions like this:

Jun 28 23:16:46 RHServer0 dotnet[56593]: Connection id "0HMRO6D462Q9A", Request id "0HMRO6D462Q9A:00000003": An unhandled exception was thrown by the application.
Jun 28 23:16:46 RHServer0 dotnet[56593]: System.DirectoryServices.Protocols.LdapException: The LDAP server is unavailable.
Jun 28 23:16:46 RHServer0 dotnet[56593]: at System.DirectoryServices.Protocols.LdapConnection.BeginSendRequest(DirectoryRequest request, TimeSpan requestTimeout, PartialResultProcessing partialMode, AsyncCa
Jun 28 23:16:46 RHServer0 dotnet[56593]: at System.DirectoryServices.Protocols.LdapConnection.BeginSendRequest(DirectoryRequest request, PartialResultProcessing partialMode, AsyncCallback callback, Object s
Jun 28 23:16:46 RHServer0 dotnet[56593]: at System.Threading.Tasks.TaskFactory1.FromAsyncImpl[TArg1,TArg2](Func5 beginMethod, Func2 endFunction, Action1 endAction, TArg1 arg1, TArg2 arg2, Object state,
Jun 28 23:16:46 RHServer0dotnet[56593]: at Microsoft.AspNetCore.Authentication.Negotiate.LdapAdapter.RetrieveClaimsAsync(LdapSettings settings, ClaimsIdentity identity, ILogger logger)
Jun 28 23:16:46 RHServer0 dotnet[56593]: at Microsoft.AspNetCore.Authentication.Negotiate.NegotiateHandler.HandleAuthenticateAsync()
Jun 28 23:16:46 RHServer0 dotnet[56593]: at Microsoft.AspNetCore.Authentication.AuthenticationHandler1.AuthenticateAsync() Jun 28 23:16:46 RHServer0 dotnet[56593]: at Microsoft.AspNetCore.Authentication.AuthenticationService.AuthenticateAsync(HttpContext context, String scheme) Jun 28 23:16:46 RHServer0 dotnet[56593]: at Microsoft.AspNetCore.Authentication.AuthenticationMiddleware.Invoke(HttpContext context) Jun 28 23:16:46 RHServer0 dotnet[56593]: at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.HttpProtocol.ProcessRequests[TContext](IHttpApplication1 application)

And the Service is still Active.
A lot of thanks for this.

[gfoidl]

Moved to an issue: #49105
Let's follow along over there.

[corsiva]

Hi @gfoidl ,
I am facing the same issue.
Is this issue fixed?