Sami created TINKERPOP-2019:
-------------------------------
Summary: Gremlin.Net.Driver.WebSocketConnection throws
System.InvalidOperationException
Key: TINKERPOP-2019
URL: https://issues.apache.org/jira/browse/TINKERPOP-2019
Project: TinkerPop
Issue Type: Bug
Components: dotnet
Affects Versions: 3.3.3
Environment: Azure App Service
Reporter: Sami
We're getting the following [System.InvalidOperationException] error message:
"There is already one outstanding 'SendAsync' call for this WebSocket instance.
ReceiveAsync and SendAsync can be called simultaneously, but at most one
outstanding operation for each of them is allowed at the same time.
Problem Id:
System.InvalidOperationException at
Gremlin.Net.Driver.WebSocketConnection+<SendMessageAsync>d__5.MoveNext"
We get this exception sporadically and only a few times out of thousands.
Unfortunately we have not been able to reproduce it.
I understand that when dealing with web sockets, it is allowed to have only a
single pending "send" or a single pending "receive".
After looking at GitHub's WebSocketConnection class, I don't see any
orchestration between SendMessageAsync's _client.SendAsync (currently line 54)
and ReceiveMessageAsync's _client.ReceiveAsync (currently line 66).
Reference Link:
[https://github.com/apache/tinkerpop/blob/master/gremlin-dotnet/src/Gremlin.Net/Driver/WebSocketConnection.cs]
I'm wondering if [not having orchestration] in the WebSocketConnection class to
keep the [single pending "send" or a single pending "receive"] rule may be the
cause.
In our .NET Core web api application, we create the GremlinConnection as a
singleton in Startup.cs and then have one central call that makes Gremlin
calls; i.e. it's a very straightforward implementation.
Startup.cs:
public void ConfigureServices(IServiceCollection services)
{
//...other stuff removed for brevity
services.AddSingleton<IGremlinConnection, GremlinConnection>();
}
Reader.cs:
public async Task<IReadOnlyCollection<dynamic>> ExecuteGremlinQuery(string
query)
{
try
{
return await _gremlinConnection.Client.SubmitAsync<dynamic>(query);
}
catch (Gremlin.Net.Driver.Exceptions.ResponseException responseException)
{
//our error handling removed for brevity!
}
}
We use the Gremlin.Net version 3.3.3 nuget package and the
Microsoft.NETCore.App SDK
Would it be possible to identify if this is indeed a bug on Gremlin.NET?
And if it is, any thoughts on a best-practice (temporary) work-around that we
can implement?
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
