feat: grpc client support multi peers (#380)

* feat: grpc client use channel manager

* cr

src/client/examples/insert.rs

@@ -12,7 +12,7 @@ fn main() {
 
 #[tokio::main]
 async fn run() {
-    let client = Client::connect("http://127.0.0.1:3001").await.unwrap();
+    let client = Client::with_urls(vec!["127.0.0.1:3001"]);
     let db = Database::new("greptime", client);
 
     let expr = InsertExpr {

src/client/examples/logical.rs

@@ -18,7 +18,7 @@ fn main() {
 
 #[tokio::main]
 async fn run() {
-    let client = Client::connect("http://127.0.0.1:3001").await.unwrap();
+    let client = Client::with_urls(vec!["127.0.0.1:3001"]);
 
     let create_table_expr = CreateExpr {
         catalog_name: Some("greptime".to_string()),

src/client/examples/physical.rs

@@ -16,7 +16,7 @@ fn main() {
 
 #[tokio::main]
 async fn run() {
-    let client = Client::connect("http://127.0.0.1:3001").await.unwrap();
+    let client = Client::with_urls(vec!["127.0.0.1:3001"]);
     let db = Database::new("greptime", client);
 
     let physical = mock_physical_plan();

src/client/examples/select.rs

@@ -10,7 +10,7 @@ fn main() {
 
 #[tokio::main]
 async fn run() {
-    let client = Client::connect("http://127.0.0.1:3001").await.unwrap();
+    let client = Client::with_urls(vec!["127.0.0.1:3001"]);
     let db = Database::new("greptime", client);
 
     let sql = Select::Sql("select * from demo".to_string());