diff --git a/src/hstreamdb/src/producer.rs b/src/hstreamdb/src/producer.rs
index 9efeed1..c5dc79f 100644
--- a/src/hstreamdb/src/producer.rs
+++ b/src/hstreamdb/src/producer.rs
@@ -71,6 +71,14 @@ impl FlushSettings {
     pub fn builder() -> FlushSettingsBuilder {
         default()
     }
+
+    pub fn sync() -> Self {
+        Self {
+            len: 0,
+            size: 0,
+            deadline: None,
+        }
+    }
 }
 
 #[derive(Default)]
diff --git a/src/hstreamdb/tests/tls_test.rs b/src/hstreamdb/tests/tls_test.rs
index 3177294..5c708ed 100644
--- a/src/hstreamdb/tests/tls_test.rs
+++ b/src/hstreamdb/tests/tls_test.rs
@@ -1,32 +1,39 @@
-// use std::{env, fs};
+use std::env;
 
-// use hstreamdb::tls::{Certificate, ClientTlsConfig, Identity};
-// use hstreamdb::{ChannelProviderSettings, Client};
+use hstreamdb::tls::{Certificate, ClientTlsConfig, Identity};
+use hstreamdb::{ChannelProviderSettings, Client};
 
-// async fn _test_tls_impl() {
-//     env::set_var("RUST_LOG", "DEBUG");
-//     env_logger::init();
+#[tokio::test(flavor = "multi_thread")]
+async fn test_tls() {
+    if let Ok(_) = env::var("ENDPOINT") {
+        test_tls_impl().await
+    } else {
+        log::warn!("cloud endpoint is not presented");
+        log::warn!("ignore tls tests");
+    }
+}
 
-//     let server_url: &str = todo!();
-//     let tls_dir: &str = todo!();
+async fn test_tls_impl() {
+    env::set_var("RUST_LOG", "DEBUG");
+    env_logger::init();
 
-//     let ca_certificate =
-// Certificate::from_pem(fs::read(format!("{tls_dir}/root_ca.crt")).unwrap());
-//     let cert = fs::read(format!("{tls_dir}/client.crt")).unwrap();
-//     let key = fs::read(format!("{tls_dir}/client.key")).unwrap();
+    let server_url: String = env::var("ENDPOINT").unwrap();
+    let ca_certificate: String = env::var("ROOT_CA").unwrap();
+    let cert = env::var("CLIENT_CRT").unwrap();
+    let key = env::var("CLIENT_KEY").unwrap();
 
-//     let client = Client::new(
-//         server_url,
-//         ChannelProviderSettings::builder()
-//             .set_tls_config(
-//                 ClientTlsConfig::new()
-//                     .ca_certificate(ca_certificate)
-//                     .identity(Identity::from_pem(cert, key)),
-//             )
-//             .build(),
-//     )
-//     .await
-//     .unwrap();
+    let client = Client::new(
+        server_url,
+        ChannelProviderSettings::builder()
+            .set_tls_config(
+                ClientTlsConfig::new()
+                    .ca_certificate(Certificate::from_pem(ca_certificate))
+                    .identity(Identity::from_pem(cert, key)),
+            )
+            .build(),
+    )
+    .await
+    .unwrap();
 
-//     log::info!("{:?}", client.list_streams().await.unwrap());
-// }
+    log::info!("{:?}", client.list_streams().await.unwrap());
+}