Add force flush of metrics

solarwinds_apm/otlp_metrics_processor.py

@@ -8,6 +8,7 @@
 import random
 from typing import TYPE_CHECKING, Any, Tuple
 
+from opentelemetry.metrics import get_meter_provider
 from opentelemetry.sdk.trace import SpanProcessor
 from opentelemetry.semconv.trace import SpanAttributes
 from opentelemetry.trace import SpanKind, StatusCode
@@ -99,6 +100,10 @@ def on_end(self, span: "ReadableSpan") -> None:
         # for SW-style trace export. This processor is for OTLP-style.
         # TODO: Cache txn_name for OTLP span export?
 
+        # Force flush metrics after every entry span via flush of all meters
+        # including PeriodicExportingMetricReader
+        get_meter_provider().force_flush()
+
     # TODO If needed for both inbound and otlp metrics, refactor
     def is_span_http(self, span: "ReadableSpan") -> bool:
         """This span from inbound HTTP request if from a SERVER by some http.method"""