Release notes XLT 8.4.0 (#244)

* Release notes XLT 8.4.0

* minor fixes

* feedback from reviewer

* feedback from reviewer

---------

Co-authored-by: Joerg Werner <j.werner@xceptance.de>

content/en/xlt/release-notes/8_4_x.md

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+---
+title: 8.4.x
+linkTitle: 8.4.x
+
+weight: 64
+type: docs
+
+date: 2024-08-05
+
+description: >
+    Real-Time Reporting of Errors and Events via OpenTelemetry
+
+sitemap:
+  changefreq: never
+  priority: 0.1
+---
+
+## XLT 8.4.0
+
+### Load Testing
+
+#### Real-Time Reporting of Errors and Events via OpenTelemetry
+
+XLT can now be configured to report error and event data to an external system while the load test is still running. This allows you to analyze errors and events as they occur without having to download the full result data and to create a load test report.
+
+XLT uses [OpenTelemetry](https://opentelemetry.io/) to report this data, specifically via OpenTelemetry's *Logs* interface. As the receiving system, we recommend using an [OpenTelemetry Collector](https://opentelemetry.io/docs/collector/). Configure this collector as needed to further process and export the data to your actual log storage, such as Google Cloud Logs.
+
+If you want to use this feature, see below for what you need to configure in your load test suite:
+
+```properties
+### Whether OpenTelemetry real-time reporting is enabled.
+xlt.reporting.otel.enabled = true
+
+### Log Record Exporter
+otel.logs.exporter = otlp
+otel.exporter.otlp.endpoint = http://localhost:4318
+otel.exporter.otlp.protocol = http/protobuf
+## Custom headers
+otel.exporter.otlp.headers =
+
+### Batch Log Record Processor
+#otel.blrp.schedule.delay = 2000
+#otel.blrp.max.queue.size = 2048
+#otel.blrp.max.export.batch.size = 512
+
+## Resource attributes
+otel.resource.attributes = project=MyShop,loadTest=42
+```
+
+After enabling the feature, you need to configure how to reach your OpenTelemetry collector. You can then define custom headers, e.g. with authorization information, etc. Optionally, you can also reconfigure the OpenTelemetry batch log record processor.
+
+Finally, define a set of custom attributes to be attached to all sent log entries. Attributes are OpenTelemetry's equivalent of metadata. They are specified as a list of key/value pairs.
+
+Use attributes to categorize the log entries in your log storage backend, for example, to separate the log entries emitted by one load test from the log entries emitted by other load tests.
+
+See the [OpenTelemetry for Java Configuration](https://opentelemetry.io/docs/languages/java/configuration/) page for all available configuration options.
+
+{{% note notitle %}}
+Please note that this feature is currently considered experimental. However, we have released it publicly to allow a wider audience to try it out and provide feedback. So if you use this feature, be prepared for possible changes.
+{{% /note %}}
+