Reduce log spam (#93)

* Only show warning message from OTEL SDK

* Disable global meter to avoid printing message

Author: RDruon

lustrefs-exporter/lustrefs_exporter.service

@@ -3,7 +3,7 @@ Description=Prometheus exporter for Lustre filesystem
 Documentation=https://github.com/whamcloud/lustrefs-exporter
 
 [Service]
-Environment=RUST_LOG=info
+Environment=RUST_LOG=info,opentelemetry_sdk=warn
 Restart=on-failure
 ExecStart=/usr/bin/lustrefs_exporter
 MemoryHigh=1750M

lustrefs-exporter/src/lib.rs

@@ -83,9 +83,5 @@ pub fn init_opentelemetry() -> Result<
         )
         .build();
 
-    // Set the global MeterProvider to the one created above.
-    // This will make all meters created with `global::meter()` use the above MeterProvider.
-    opentelemetry::global::set_meter_provider(provider.clone());
-
     Ok((provider, registry))
 }