[jira] [Commented] (TINKERPOP-2268) Prevent Connection Failure from Hanging

["Florian Hockmann (Jira)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/TINKERPOP-2268?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17073856#comment-17073856 ] 

Florian Hockmann commented on TINKERPOP-2268:
---------------------------------------------

I wonder whether the fix for TINKERPOP-2288 will also fix this one as it replaces closed connections in the background automatically and also includes a retry in case that no open connection is available. [~github5775] would you be available to try the fix [I described there|https://issues.apache.org/jira/browse/TINKERPOP-2288?focusedCommentId=17065772&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-17065772]? I also attached a NuGet package with this fix to the ticket.

> Prevent Connection Failure from Hanging
> ---------------------------------------
>
>                 Key: TINKERPOP-2268
>                 URL: https://issues.apache.org/jira/browse/TINKERPOP-2268
>             Project: TinkerPop
>          Issue Type: Improvement
>          Components: dotnet
>         Environment: .Net Core
>            Reporter: MichaelZ
>            Priority: Major
>   Original Estimate: 24h
>  Remaining Estimate: 24h
>
> When a consumer of the Gremlin.Net client calls to execute a Gremlin query, i.e. "SubmitAsync," and there is no valid connection, there will be a costly timeout error. I have experienced 30 to 90 second timeouts.
> I was on vacation, so I didn't do this earlier, but I have written a little patch that will refresh the connection pool when there is no valid connection, and it works flawlessly.  This is quick code, and there is a more elegant solution, but what I did is to check IsOpen on the first connection snapshot, and create a new pool if it was stale.  Here is is the code on the GremlinClient object:
> {code}
> private ConnectionPool _connectionPool; //{color:#ff0000}used to be readonly{color}
> // member variables
>  private readonly GremlinServer _gremlinServer = null;
>  private readonly GraphSONReader _graphSONReader = null;
>  private readonly GraphSONWriter _graphSONWriter = null;
>  private readonly string _mimeType = null;
> private readonly ConnectionPoolSettings _connectionPoolSettings = null;
> private readonly Action<ClientWebSocketOptions> _webSocketConfiguration = null;
>  //
> public GremlinClient(GremlinServer gremlinServer, GraphSONReader graphSONReader = null,
>  GraphSONWriter graphSONWriter = null, string mimeType = null,
>  ConnectionPoolSettings connectionPoolSettings = null,
>  Action<ClientWebSocketOptions> webSocketConfiguration = null)
>  {
>  //
>  _gremlinServer = gremlinServer;
>  _graphSONReader = graphSONReader;
>  _graphSONWriter = graphSONWriter;
>  _mimeType = mimeType;
>  _connectionPoolSettings = connectionPoolSettings;
>  _webSocketConfiguration = webSocketConfiguration;
>  //
>  {color:#ff0000}NewConnectionPool(){color};
>  }
> private void NewConnectionPool()
> {
> var reader = _graphSONReader ?? new GraphSON3Reader();
> var writer = _graphSONWriter ?? new GraphSON3Writer();
> var connectionFactory = new ConnectionFactory(_gremlinServer, reader, writer, _mimeType ?? DefaultMimeType, _webSocketConfiguration);
> _connectionPool = new ConnectionPool(connectionFactory, _connectionPoolSettings ?? new ConnectionPoolSettings());
> }
> /// <summary>
>  /// Provides whether the first available connection snapshot in pool is still open.
>  /// </summary>
>  {color:#ff0000}private{color} bool HasOpenConnection => (bool)_connectionPool?.FirstConnectionSnapshot?.IsOpen;
> /// <inheritdoc />
>  public async Task<ResultSet<T>> SubmitAsync<T>(RequestMessage requestMessage)
>  {
>  if (!HasOpenConnection)
>  {
>  Debug.WriteLine("=====================================");
>  Debug.WriteLine("new connection pool");
> {color:#ff0000}NewConnectionPool(){color};
>  }
> using (var connection = await _connectionPool.GetAvailableConnectionAsync().ConfigureAwait(false))
> { return await connection.SubmitAsync<T>(requestMessage).ConfigureAwait(false); }
> }
> {code}
>  



--
This message was sent by Atlassian Jira
(v8.3.4#803005)