fix: revert placement of logging init if otel exports is disabled (#3797)

Signed-off-by: mohammedabdulwahhab <furkhan324@berkeley.edu>

deploy/tracing/README.md

@@ -30,6 +30,8 @@ Dynamo's tracing is configured via environment variables. For complete logging d
 | `OTEL_EXPORT_ENDPOINT` | OTLP gRPC endpoint for Tempo | `http://localhost:4317` (local) or `http://tempo:4317` (docker) |
 | `OTEL_SERVICE_NAME` | Service name for identifying components | `dynamo-frontend`, `dynamo-worker-prefill`, `dynamo-worker-decode` |
 
+**Note:** When `OTEL_EXPORT_ENABLED=1`, logging initialization is deferred until the runtime is available (required by the OTEL exporter). This means some early logs will be dropped. This will be fixed in a future release.
+
 ### Example Configuration
 
 ```bash

lib/bindings/python/rust/lib.rs

@@ -118,6 +118,18 @@ fn create_request_context(
 /// import the module.
 #[pymodule]
 fn _core(m: &Bound<'_, PyModule>) -> PyResult<()> {
+    // Initialize logging early unless OTEL export is enabled (which requires tokio runtime)
+    if std::env::var("OTEL_EXPORT_ENABLED")
+        .map(|v| v == "1")
+        .unwrap_or(false)
+    {
+        eprintln!(
+            "Warning: OTEL_EXPORT_ENABLED=1 detected. Logging initialization deferred until runtime is available. Early logs may be dropped."
+        );
+    } else {
+        rs::logging::init();
+    }
+
     m.add_function(wrap_pyfunction!(llm::kv::compute_block_hash_for_seq_py, m)?)?;
     m.add_function(wrap_pyfunction!(log_message, m)?)?;
     m.add_function(wrap_pyfunction!(register_llm, m)?)?;
@@ -425,9 +437,14 @@ impl DistributedRuntime {
 
         // Initialize logging in context where tokio runtime is available
         // otel exporter requires it
-        runtime.secondary().block_on(async {
-            rs::logging::init();
-        });
+        if std::env::var("OTEL_EXPORT_ENABLED")
+            .map(|v| v == "1")
+            .unwrap_or(false)
+        {
+            runtime.secondary().block_on(async {
+                rs::logging::init();
+            });
+        }
 
         let inner =
             if is_static {