diff --git a/services/commtest/src/send_log.rs b/services/commtest/src/send_log.rs
new file mode 100644
--- /dev/null
+++ b/services/commtest/src/send_log.rs
@@ -0,0 +1,49 @@
+use crate::backup_utils::{
+  proto::send_log_request::Data::*, proto::SendLogRequest, BackupServiceClient,
+};
+
+use tonic::Request;
+
+use crate::tools::generate_nbytes;
+use crate::backup_utils::BackupData;
+
+pub async fn run(
+  client: &mut BackupServiceClient<tonic::transport::Channel>,
+  backup_data: &BackupData,
+  log_index: usize
+) -> Result<String, Box<dyn std::error::Error>> {
+  println!("send log");
+  let cloned_user_id = backup_data.user_id.clone();
+  let cloned_backup_id = backup_data.backup_id.clone();
+  let cloned_log_sizes = backup_data.logs_sizes[log_index].clone();
+  let outbound = async_stream::stream! {
+    println!(" - sending user id");
+    let request = SendLogRequest {
+      data: Some(UserId(cloned_user_id)),
+    };
+    yield request;
+    println!(" - sending backup id");
+    let request = SendLogRequest {
+      data: Some(BackupId(cloned_backup_id)),
+    };
+    yield request;
+    println!(" - sending log hash");
+    let request = SendLogRequest {
+      data: Some(LogHash(vec![65,66,67,66+(log_index as u8)])),
+    };
+    yield request;
+    println!(" - sending log data");
+    for log_size in cloned_log_sizes {
+      println!("  - sending log data {}", log_size);
+      let request = SendLogRequest {
+        data: Some(LogData(generate_nbytes(log_size, None))),
+      };
+      yield request;
+    }
+  };
+
+  let response = client.send_log(Request::new(outbound)).await?;
+  let inbound = response.into_inner();
+  println!("send log response: {:?}", inbound.log_checkpoint);
+  Ok(inbound.log_checkpoint)
+}