Opentelemetry to export traces to Database

[Yahire3388]

Hi,

I am using opentelemetry java agent to trace web application and zipkin as a collector. Instead of exporting the data to zipkin, can we directly store the data in database like Postgres, mongo or cassandra?

Thanks in advance :)

[mateuszrzeszutek]

Hey @Yahire3388 ,
This could be achieved by implementing a custom SpanExporter (and wiring it using a ConfigurableSpanExporterProvider) in a custom extension jar. You could probably start with copying the extension project and trying it out - note that the extension jar is separate from your main application, and if you want to use a database you have to keep in mind that the extension will need to setup and manage connections by itself.

[Yahire3388]

Hi @mateuszrzeszutek

I wanted to proceed with auto instrumentation only. Also, I looked into the github repository to see if i can setup the code and debug it to add my code and create jar out of it, but i am not able to understand the structure of the code as i can see some gradle files, kotlin files. used following github project url : https://github.com/open-telemetry/opentelemetry-java-instrumentation.

Can you please help to setup the project in my local or which source code is used to create the jar, or provide with a custom jar which will export the traces directly to the database. This can be a new idea to save the traces to database directly eliminating the need of collector.

[trask]

provide with a custom jar which will export the traces directly to the database. This can be a new idea to save the traces to database directly eliminating the need of collector.

hi @Yahire3388! this is a very big undertaking, I'd strongly recommend looking at existing solutions (either OSS or commercial) for storing and viewing your traces

[Yahire3388]

Hi,

I am trying this extension jar. But when i run the java agent with this extension jar, it is not adding any of the custom attribute or anything.

When i looked in the gradle script it is something like this :
tasks {
test {
useJUnitPlatform()

inputs.files(layout.files(tasks.shadowJar))
inputs.files(layout.files(tasks.extendedAgent))

systemProperty 'io.opentelemetry.smoketest.agentPath', configurations.otel.singleFile.absolutePath
systemProperty 'io.opentelemetry.smoketest.extendedAgentPath', tasks.extendedAgent.archiveFile.get().asFile.absolutePath
systemProperty 'io.opentelemetry.smoketest.extensionPath', tasks.shadowJar.archiveFile.get().asFile.absolutePath

}

compileJava {
options.release.set(8)
}

assemble.dependsOn(shadowJar)
}

Do we have t add any task regarding main class? Also, I was hoping if i add db connection code in DemoSpanExporter.java it will store the data in DB. Is it a correct way?

public class DemoSpanExporter implements SpanExporter {
@OverRide
public CompletableResultCode export(Collection spans) {
System.out.printf("%d spans exported%n", spans.size());

// Add database code here

return CompletableResultCode.ofSuccess();

}

@OverRide
public CompletableResultCode flush() {
return CompletableResultCode.ofSuccess();
}

@OverRide
public CompletableResultCode shutdown() {
return CompletableResultCode.ofSuccess();
}
}

[mateuszrzeszutek]

Do we have t add any task regarding main class?

No, there's no need to have a main class in an extension -- the extension classes are loaded via the ServiceLoader mechanism (look for either @AutoService annotation or META-INF/services files).

Also, I was hoping if i add db connection code in DemoSpanExporter.java it will store the data in DB. Is it a correct way?

// Add database code here

Yes, that looks like more or less the correct place.