Apm-agent-dotnet: System.NullReferenceException when using Oracle

[fernandolamp]

Describe the bug
Hi guys,
I am using oracle with devart provider and my string connection is:

Data Source=(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=172.21.25.186)(PORT=1521))(CONNECT_DATA=(SERVICE_NAME=ORCLCDB)));User Id=SAJDDL; Direct=True;

When I try to get data from database, elastic apm throws a exception:

System.NullReferenceException: Object reference not set to an instance of an object.
at Elastic.Apm.Model.DbSpanCommon.GetDestination(String dbConnectionString, Boolean isEmbeddedDb, Nullable1 defaultPort) at Elastic.Apm.Model.DbSpanCommon.EndSpan(Span span, IDbCommand dbCommand, Nullable1 duration)
at Elastic.Apm.EntityFrameworkCore.EfCoreDiagnosticListener.OnNext(KeyValuePair`2 kv)
at System.Diagnostics.DiagnosticListener.Write(String name, Object value)

The problem happen in this method:

    internal Destination GetDestination(
      string dbConnectionString,
      bool isEmbeddedDb,
      int? defaultPort)
    {
      if (isEmbeddedDb || dbConnectionString == null)
        return (Destination) null;
      Destination destination = this._dbConnectionStringParser.ExtractDestination(dbConnectionString);
      if (!destination.Port.HasValue)  <----- HERE
        destination.Port = defaultPort;
      return destination;
    }

Below I try explain why this happened:

Debuging:

In DbSpanCommon.cs:
internal Destination GetDestination

My string connection:

DbConnectionStringParser.cs:

When try to extract destination, I noticed that the value of "key/value" pair is null:

The key is found but destination is null, and when he try to access destination.Port.HasValue:

The exception is thrown.

To Reproduce
Steps to reproduce the behavior:

1. Configure oracle string connection like this: Data Source=(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=172.21.25.186)(PORT=1521))(CONNECT_DATA=(SERVICE_NAME=ORCLCDB)));User Id=SAJDDL; Direct=True;

1. Try to retrieve value from database

Expected behavior

Find database destination and don´t throw NullPointReference exception

Thank you in advance, elastic apm is awesome!

[fernandolamp]

After update to version 1.4.0 the problem was solved

[SergeyKleyman]

@fernandolamp Could you please double check if indeed 1.4.0 resolves your issue? While we did include a fix (#749) for another issue (#746) in DB connection string parser I am not sure that fix could have done anything to resolve your issue.

[Cesaragsilva]

@SergeyKleyman and @gregkalapos the problem are occurring in .net core 2.2 with oracle yet, can you check again?

i'm using the last version of the package.

[gregkalapos]

@SergeyKleyman and @gregkalapos the problem are occurring in .net core 2.2 with oracle yet, can you check again?

i'm using the last version of the package.

@Cesaragsilva could you give us the logs? Especially the callstack would be interesting. Given that the code changed in this area I expect a different callstack - but let's see...

[SergeyKleyman]

Please correct me if I am wrong - the fix (#795) is not included in the latest (which is at the moment 1.4.0) release.

[gregkalapos]

Please correct me if I am wrong - the fix (#795) is not included in the latest (which is at the moment 1.4.0) release.

😱 Yes, you are right - thanks for pointing this out! #795 was merged after 1.4 was released. Now I remember the full story.

Ok, so, now it makes sense - @Cesaragsilva this will be in the next release which will be out very soon. Sorry about the confusion.

Thanks @SergeyKleyman.

[Cesaragsilva]

@gregkalapos and @SergeyKleyman Thank you for check it. I'm await the next version eagerly