Fix error taking a backup using PXB 8.0.35

Latest versions of PXB support only one type of stream and
it should be specified using `=`. This fix makes it work for both 8.0.30
and recent versions.

Also decreased expected value of bytes read in the test for the backup,
it seems there was a changed which reduced it a bit.

.github/workflows/tests.yaml

@@ -95,6 +95,10 @@ jobs:
             percona-version: "8.0.32-26-1.focal"
             python-version: "3.11"
             ubuntu-version: "20.04"
+          - mysql-version: "8.0.35"
+            percona-version: "8.0.35-30-1.focal"
+            python-version: "3.11"
+            ubuntu-version: "20.04"
 
     steps:
       - id: checkout-code

myhoard/basebackup_operation.py

@@ -134,8 +134,7 @@ def create_backup(self):
                     encryption_key_file.name,
                     "--no-version-check",
                     f"--parallel={self.copy_threads}",
-                    "--stream",
-                    "xbstream",
+                    "--stream=xbstream",
                     "--target-dir",
                     self.temp_dir,
                     "--extra-lsndir",

test/test_basebackup_operation.py

@@ -92,8 +92,8 @@ def stream_handler(stream):
     assert op.binlog_info["file_name"] == master_status["File"]
     assert op.binlog_info["file_position"] == master_status["Position"]
 
-    # Even almost empty backup is a few megs due to standard files that are always included
-    assert bytes_read[0] > 2 * 1024 * 1024
+    # Even almost empty backup is at least 1.5 megs due to standard files that are always included
+    assert bytes_read[0] > 1.5 * 1024 * 1024
 
 
 def test_stream_handler_error_is_propagated(mysql_master):