Flush export queue when it reaches max_export_batch_size (#1521)

Author: anton-ryzhov

CHANGELOG.md

@@ -26,10 +26,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Add urllib to opentelemetry-bootstrap target list
   ([#1584])(https://github.com/open-telemetry/opentelemetry-python/pull/1584)
 
-
 ### Changed
 - Read-only Span attributes have been moved to ReadableSpan class
   ([#1560](https://github.com/open-telemetry/opentelemetry-python/pull/1560))
+- `BatchExportSpanProcessor` flushes export queue when it reaches `max_export_batch_size`
+  ([#1521])(https://github.com/open-telemetry/opentelemetry-python/pull/1521)
 
 ### Removed
 - Remove Configuration

opentelemetry-sdk/src/opentelemetry/sdk/trace/export/__init__.py

@@ -200,7 +200,7 @@ def on_end(self, span: ReadableSpan) -> None:
 
         self.queue.appendleft(span)
 
-        if len(self.queue) >= self.max_queue_size // 2:
+        if len(self.queue) >= self.max_export_batch_size:
             with self.condition:
                 self.condition.notify()