diff --git a/ballista/rust/core/src/serde/logical_plan/from_proto.rs b/ballista/rust/core/src/serde/logical_plan/from_proto.rs
index 389c1bdb722e..10cc5e156889 100644
--- a/ballista/rust/core/src/serde/logical_plan/from_proto.rs
+++ b/ballista/rust/core/src/serde/logical_plan/from_proto.rs
@@ -1102,6 +1102,7 @@ impl TryInto<Expr> for &protobuf::LogicalExprNode {
                 }
             }
             ExprType::ScalarUdfProtoExpr(expr) => {
+                println!("from_proto to logical plan-----------------");
                 if let Some(udf_plugin_manager) = get_udf_plugin_manager("") {
                     let fun = udf_plugin_manager
                         .scalar_udfs
@@ -1112,6 +1113,7 @@ impl TryInto<Expr> for &protobuf::LogicalExprNode {
                                 expr.fun_name.to_string()
                             ))
                         })?;
+                    println!("found udf-------------------");
                     let fun_arc = fun.clone();
                     let fun_args = &expr.args;
                     let args: Vec<Expr> = fun_args
diff --git a/ballista/rust/core/src/serde/physical_plan/from_proto.rs b/ballista/rust/core/src/serde/physical_plan/from_proto.rs
index 38c04ef29dd3..1e3052ff1adb 100644
--- a/ballista/rust/core/src/serde/physical_plan/from_proto.rs
+++ b/ballista/rust/core/src/serde/physical_plan/from_proto.rs
@@ -581,6 +581,7 @@ impl TryFrom<&protobuf::PhysicalExprNode> for Arc<dyn PhysicalExpr> {
             }
             // argo engine add.
             ExprType::ScalarUdfProtoExpr(e) => {
+                println!("from proto to physical plan----------------");
                 if let Some(udf_plugin_manager) = get_udf_plugin_manager("") {
                     let fun = udf_plugin_manager
                         .scalar_udfs
@@ -591,8 +592,8 @@ impl TryFrom<&protobuf::PhysicalExprNode> for Arc<dyn PhysicalExpr> {
                                 &e.fun_name.to_owned()
                             ))
                         })?;
-
                     let scalar_udf = &*fun.clone();
+                    println!("found udf-------------------");
                     let args = e
                         .expr
                         .iter()
diff --git a/ballista/rust/scheduler/src/lib.rs b/ballista/rust/scheduler/src/lib.rs
index 61da0d9cbf3e..9346f7df37a1 100644
--- a/ballista/rust/scheduler/src/lib.rs
+++ b/ballista/rust/scheduler/src/lib.rs
@@ -328,6 +328,7 @@ impl SchedulerGrpc for SchedulerServer {
         &self,
         request: Request<ExecuteQueryParams>,
     ) -> std::result::Result<Response<ExecuteQueryResult>, tonic::Status> {
+        println!("execute query in scheduler--------------");
         if let ExecuteQueryParams {
             query: Some(query),
             settings,
@@ -347,6 +348,7 @@ impl SchedulerGrpc for SchedulerServer {
             let plan = match query {
                 Query::LogicalPlan(logical_plan) => {
                     // parse protobuf
+                    println!("in ballista logical_plan to proto");
                     (&logical_plan).try_into().map_err(|e| {
                         let msg = format!("Could not parse logical plan protobuf: {}", e);
                         error!("{}", msg);
diff --git a/datafusion/src/execution/context.rs b/datafusion/src/execution/context.rs
index 5e4e3ef6b711..066cc1b5809b 100644
--- a/datafusion/src/execution/context.rs
+++ b/datafusion/src/execution/context.rs
@@ -197,6 +197,7 @@ impl ExecutionContext {
         };
 
         // register udf
+        println!("register udf to context---------------");
         if let Some(udf_plugin_manager) =
             get_udf_plugin_manager(config.plugin_dir.as_str())
         {
@@ -212,6 +213,7 @@ impl ExecutionContext {
                     context.register_udaf((**aggregate_udf).clone())
                 });
         }
+        println!("register udf to context--------success-------");
         context
     }
 
diff --git a/datafusion/src/plugin/udf.rs b/datafusion/src/plugin/udf.rs
index a906554956e5..eef32b231149 100644
--- a/datafusion/src/plugin/udf.rs
+++ b/datafusion/src/plugin/udf.rs
@@ -104,6 +104,7 @@ impl PluginRegistrar for UDFPluginManager {
                     Ok(())
                 }
             })?;
+        self.libraries.push(library);
         Ok(())
     }
 
@@ -136,6 +137,7 @@ macro_rules! declare_udf_plugin {
 
 /// get a Option of Immutable UDFPluginManager
 pub fn get_udf_plugin_manager(path: &str) -> Option<UDFPluginManager> {
+    println!("get_udf_plugin_manager:{}", path);
     let udf_plugin_manager_opt = {
         let gpm = global_plugin_manager(path).lock().unwrap();
         let plugin_registrar_opt = gpm.plugin_managers.get(&PluginEnum::UDF);