feat: read/write works in distributed mode 🎉 (#2327)

* add do_get method to RegionRequestHandler

Signed-off-by: Ruihang Xia <waynestxia@gmail.com>

* move RegionRequestHandler to client crate

Signed-off-by: Ruihang Xia <waynestxia@gmail.com>

* use RegionRequestHandler in MergeScan

Signed-off-by: Ruihang Xia <waynestxia@gmail.com>

* minor fix

Signed-off-by: Ruihang Xia <waynestxia@gmail.com>

* ignore tests

Signed-off-by: Ruihang Xia <waynestxia@gmail.com>

* fix format

Signed-off-by: Ruihang Xia <waynestxia@gmail.com>

---------

Signed-off-by: Ruihang Xia <waynestxia@gmail.com>

src/datanode/src/datanode.rs

@@ -406,9 +406,8 @@ impl Datanode {
         let query_engine_factory = QueryEngineFactory::new_with_plugins(
             // query engine in datanode only executes plan with resolved table source.
             MemoryCatalogManager::with_default_setup(),
+            None,
             false,
-            None,
-            None,
             plugins,
         );
         let query_engine = query_engine_factory.query_engine();

src/datanode/src/instance.rs

@@ -241,13 +241,8 @@ impl Instance {
             }
         };
 
-        let factory = QueryEngineFactory::new_with_plugins(
-            catalog_manager.clone(),
-            false,
-            None,
-            None,
-            plugins,
-        );
+        let factory =
+            QueryEngineFactory::new_with_plugins(catalog_manager.clone(), None, false, plugins);
         let query_engine = factory.query_engine();
         let procedure_manager = create_procedure_manager(
             opts.node_id.unwrap_or(0),

src/datanode/src/region_server.rs

@@ -179,6 +179,7 @@ impl RegionServerInner {
 
     pub fn register_engine(&self, engine: RegionEngineRef) {
         let engine_name = engine.name();
+        info!("Region Engine {engine_name} is registered");
         self.engines
             .write()
             .unwrap()