A test with non-deterministic results illustrating the bug.

src/test/regress/expected/issue_7477.out

@@ -0,0 +1,62 @@
+--- Test for updating a table that has a foreign key reference to another reference table.
+--- Issue #7477: Distributed deadlock after issuing a simple UPDATE statement
+--- https://github.com/citusdata/citus/issues/7477
+CREATE TABLE table1 (id INT PRIMARY KEY);
+SELECT create_reference_table('table1');
+ create_reference_table
+---------------------------------------------------------------------
+
+(1 row)
+
+INSERT INTO table1 VALUES (1);
+CREATE TABLE table2 (
+    id INT,
+    info TEXT,
+    CONSTRAINT table1_id_fk FOREIGN KEY (id) REFERENCES table1 (id)
+    );
+SELECT create_reference_table('table2');
+ create_reference_table
+---------------------------------------------------------------------
+
+(1 row)
+
+INSERT INTO table2 VALUES (1, 'test');
+--- Runs the update command in parallel on workers.
+--- Due to bug #7477, before the fix, the result is non-deterministic
+--- and have several rows of the form:
+---  localhost |     57638 | f       | ERROR:  deadlock detected
+---  localhost |     57637 | f       | ERROR:  deadlock detected
+---  localhost |     57637 | f       | ERROR:  canceling the transaction since it was involved in a distributed deadlock
+SELECT * FROM master_run_on_worker(
+    ARRAY['localhost', 'localhost','localhost', 'localhost','localhost',
+            'localhost','localhost', 'localhost','localhost', 'localhost']::text[],
+    ARRAY[57638, 57637, 57637, 57638, 57637, 57638, 57637, 57638, 57638, 57637]::int[],
+    ARRAY['UPDATE table2 SET info = ''test_update'' WHERE id = 1',
+            'UPDATE table2 SET info = ''test_update'' WHERE id = 1',
+            'UPDATE table2 SET info = ''test_update'' WHERE id = 1',
+            'UPDATE table2 SET info = ''test_update'' WHERE id = 1',
+            'UPDATE table2 SET info = ''test_update'' WHERE id = 1',
+            'UPDATE table2 SET info = ''test_update'' WHERE id = 1',
+            'UPDATE table2 SET info = ''test_update'' WHERE id = 1',
+            'UPDATE table2 SET info = ''test_update'' WHERE id = 1',
+            'UPDATE table2 SET info = ''test_update'' WHERE id = 1',
+            'UPDATE table2 SET info = ''test_update'' WHERE id = 1'
+            ]::text[],
+    true);
+ node_name | node_port | success |                                      result
+---------------------------------------------------------------------
+ localhost |     57638 | f       | ERROR:  deadlock detected
+ localhost |     57637 | t       | UPDATE 1
+ localhost |     57637 | f       | ERROR:  deadlock detected
+ localhost |     57638 | f       | ERROR:  deadlock detected
+ localhost |     57637 | f       | ERROR:  canceling the transaction since it was involved in a distributed deadlock
+ localhost |     57638 | f       | ERROR:  deadlock detected
+ localhost |     57637 | f       | ERROR:  deadlock detected
+ localhost |     57638 | f       | ERROR:  deadlock detected
+ localhost |     57638 | f       | ERROR:  canceling the transaction since it was involved in a distributed deadlock
+ localhost |     57637 | f       | ERROR:  deadlock detected
+(10 rows)
+
+--- cleanup
+DROP TABLE table2;
+DROP TABLE table1;

src/test/regress/multi_schedule

@@ -103,7 +103,7 @@ test: multi_dropped_column_aliases foreign_key_restriction_enforcement
 test: binary_protocol
 test: alter_table_set_access_method
 test: alter_distributed_table
-test: issue_5248 issue_5099 issue_5763 issue_6543 issue_6758
+test: issue_5248 issue_5099 issue_5763 issue_6543 issue_6758 issue_7477
 test: object_propagation_debug
 test: undistribute_table
 test: run_command_on_all_nodes

src/test/regress/sql/issue_7477.sql

@@ -0,0 +1,44 @@
+
+--- Test for updating a table that has a foreign key reference to another reference table. 
+--- Issue #7477: Distributed deadlock after issuing a simple UPDATE statement
+--- https://github.com/citusdata/citus/issues/7477
+
+CREATE TABLE table1 (id INT PRIMARY KEY);
+SELECT create_reference_table('table1');
+INSERT INTO table1 VALUES (1);
+
+CREATE TABLE table2 (
+    id INT,
+    info TEXT,
+    CONSTRAINT table1_id_fk FOREIGN KEY (id) REFERENCES table1 (id)
+    );
+SELECT create_reference_table('table2');
+INSERT INTO table2 VALUES (1, 'test');
+
+--- Runs the update command in parallel on workers. 
+--- Due to bug #7477, before the fix, the result is non-deterministic
+--- and have several rows of the form:
+---  localhost |     57638 | f       | ERROR:  deadlock detected
+---  localhost |     57637 | f       | ERROR:  deadlock detected
+---  localhost |     57637 | f       | ERROR:  canceling the transaction since it was involved in a distributed deadlock
+
+SELECT * FROM master_run_on_worker(
+    ARRAY['localhost', 'localhost','localhost', 'localhost','localhost', 
+            'localhost','localhost', 'localhost','localhost', 'localhost']::text[],
+    ARRAY[57638, 57637, 57637, 57638, 57637, 57638, 57637, 57638, 57638, 57637]::int[],
+    ARRAY['UPDATE table2 SET info = ''test_update'' WHERE id = 1',
+            'UPDATE table2 SET info = ''test_update'' WHERE id = 1',
+            'UPDATE table2 SET info = ''test_update'' WHERE id = 1',
+            'UPDATE table2 SET info = ''test_update'' WHERE id = 1',
+            'UPDATE table2 SET info = ''test_update'' WHERE id = 1',
+            'UPDATE table2 SET info = ''test_update'' WHERE id = 1',
+            'UPDATE table2 SET info = ''test_update'' WHERE id = 1',
+            'UPDATE table2 SET info = ''test_update'' WHERE id = 1',
+            'UPDATE table2 SET info = ''test_update'' WHERE id = 1',
+            'UPDATE table2 SET info = ''test_update'' WHERE id = 1'
+            ]::text[],
+    true);
+
+--- cleanup
+DROP TABLE table2;
+DROP TABLE table1;