Fix SHOW REPLICATION ROLE and SHOW REPLICAS (#376)

src/query/interpreter.cpp

@@ -450,7 +450,7 @@ Callback HandleReplicationQuery(ReplicationQuery *repl_query, const Parameters &
       return callback;
     }
     case ReplicationQuery::Action::SHOW_REPLICATION_ROLE: {
-      callback.header = {"replication mode"};
+      callback.header = {"replication role"};
       callback.fn = [handler = ReplQueryHandler{interpreter_context->db}] {
         auto mode = handler.ShowReplicationRole();
         switch (mode) {
@@ -516,7 +516,6 @@ Callback HandleReplicationQuery(ReplicationQuery *repl_query, const Parameters &
               typed_replica.emplace_back(TypedValue("async"));
               break;
           }
-          typed_replica.emplace_back(TypedValue(static_cast<int64_t>(replica.sync_mode)));
           if (replica.timeout) {
             typed_replica.emplace_back(TypedValue(*replica.timeout));
           } else {

tests/e2e/replication/CMakeLists.txt

@@ -5,3 +5,7 @@ target_link_libraries(memgraph__e2e__replication__constraints gflags mgclient mg
 
 add_executable(memgraph__e2e__replication__read_write_benchmark read_write_benchmark.cpp)
 target_link_libraries(memgraph__e2e__replication__read_write_benchmark gflags json mgclient mg-utils mg-io Threads::Threads)
+
+copy_e2e_python_files(replication_show common.py)
+copy_e2e_python_files(replication_show conftest.py)
+copy_e2e_python_files(replication_show show.py)

tests/e2e/replication/common.py

@@ -0,0 +1,26 @@
+# Copyright 2022 Memgraph Ltd.
+#
+# Use of this software is governed by the Business Source License
+# included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+# License, and you may not use this file except in compliance with the Business Source License.
+#
+# As of the Change Date specified in that file, in accordance with
+# the Business Source License, use of this software will be governed
+# by the Apache License, Version 2.0, included in the file
+# licenses/APL.txt.
+
+import mgclient
+import typing
+
+
+def execute_and_fetch_all(
+    cursor: mgclient.Cursor, query: str, params: dict = {}
+) -> typing.List[tuple]:
+    cursor.execute(query, params)
+    return cursor.fetchall()
+
+
+def connect(**kwargs) -> mgclient.Connection:
+    connection = mgclient.connect(**kwargs)
+    connection.autocommit = True
+    return connection

tests/e2e/replication/conftest.py

@@ -0,0 +1,44 @@
+# Copyright 2022 Memgraph Ltd.
+#
+# Use of this software is governed by the Business Source License
+# included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+# License, and you may not use this file except in compliance with the Business Source License.
+#
+# As of the Change Date specified in that file, in accordance with
+# the Business Source License, use of this software will be governed
+# by the Apache License, Version 2.0, included in the file
+# licenses/APL.txt.
+
+import pytest
+
+from common import execute_and_fetch_all, connect
+
+
+# The fixture here is more complex because the connection has to be
+# parameterized based on the test parameters (info has to be available on both
+# sides).
+#
+# https://docs.pytest.org/en/latest/example/parametrize.html#indirect-parametrization
+# is not an elegant/feasible solution here.
+#
+# The solution was independently developed and then I stumbled upon the same
+# approach here https://stackoverflow.com/a/68286553/4888809 which I think is
+# optimal.
+@pytest.fixture(scope="function")
+def connection():
+    connection_holder = None
+    role_holder = None
+
+    def inner_connection(port, role):
+        nonlocal connection_holder, role_holder
+        connection_holder = connect(host="localhost", port=port)
+        role_holder = role
+        return connection_holder
+
+    yield inner_connection
+
+    # Only main instance can be cleaned up because replicas do NOT accept
+    # writes.
+    if role_holder == "main":
+        cursor = connection_holder.cursor()
+        execute_and_fetch_all(cursor, "MATCH (n) DETACH DELETE n;")

tests/e2e/replication/show.py

@@ -0,0 +1,46 @@
+# Copyright 2022 Memgraph Ltd.
+#
+# Use of this software is governed by the Business Source License
+# included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+# License, and you may not use this file except in compliance with the Business Source License.
+#
+# As of the Change Date specified in that file, in accordance with
+# the Business Source License, use of this software will be governed
+# by the Apache License, Version 2.0, included in the file
+# licenses/APL.txt.
+
+import sys
+
+import pytest
+from common import execute_and_fetch_all
+
+
+@pytest.mark.parametrize(
+    "port, role",
+    [(7687, "main"), (7688, "replica"), (7689, "replica"), (7690, "replica")],
+)
+def test_show_replication_role(port, role, connection):
+    cursor = connection(port, role).cursor()
+    data = execute_and_fetch_all(cursor, "SHOW REPLICATION ROLE;")
+    assert cursor.description[0].name == "replication role"
+    assert data[0][0] == role
+
+
+def test_show_replicas(connection):
+    cursor = connection(7687, "main").cursor()
+    actual_data = set(execute_and_fetch_all(cursor, "SHOW REPLICAS;"))
+
+    expected_column_names = {"name", "socket_address", "sync_mode", "timeout"}
+    actual_column_names = {x.name for x in cursor.description}
+    assert expected_column_names == actual_column_names
+
+    expected_data = {
+        ("replica_1", "127.0.0.1:10001", "sync", 0),
+        ("replica_2", "127.0.0.1:10002", "sync", 1.0),
+        ("replica_3", "127.0.0.1:10003", "async", None),
+    }
+    assert expected_data == actual_data
+
+
+if __name__ == "__main__":
+    sys.exit(pytest.main([__file__, "-rA"]))

tests/e2e/replication/workloads.yaml

@@ -46,4 +46,31 @@ workloads:
     args: []
     <<: *template_cluster
 
-
+  - name: "Show"
+    binary: "tests/e2e/pytest_runner.sh"
+    args: ["replication/show.py"]
+    cluster:
+      replica_1:
+        args: ["--bolt-port", "7688", "--log-level=TRACE"]
+        log_file: "replication-e2e-replica1.log"
+        setup_queries: ["SET REPLICATION ROLE TO REPLICA WITH PORT 10001;"]
+        validation_queries: []
+      replica_2:
+        args: ["--bolt-port", "7689", "--log-level=TRACE"]
+        log_file: "replication-e2e-replica2.log"
+        setup_queries: ["SET REPLICATION ROLE TO REPLICA WITH PORT 10002;"]
+        validation_queries: []
+      replica_3:
+        args: ["--bolt-port", "7690", "--log-level=TRACE"]
+        log_file: "replication-e2e-replica3.log"
+        setup_queries: ["SET REPLICATION ROLE TO REPLICA WITH PORT 10003;"]
+        validation_queries: []
+      main:
+        args: ["--bolt-port", "7687", "--log-level=TRACE"]
+        log_file: "replication-e2e-main.log"
+        setup_queries: [
+          "REGISTER REPLICA replica_1 SYNC WITH TIMEOUT 0 TO '127.0.0.1:10001'",
+          "REGISTER REPLICA replica_2 SYNC WITH TIMEOUT 1 TO '127.0.0.1:10002'",
+          "REGISTER REPLICA replica_3 ASYNC TO '127.0.0.1:10003'"
+        ]
+        validation_queries: []