Merge pull request #2846 from juannyG/master

Address flaky transaction tests

Author: bagerard

.github/workflows/start_mongo.sh

@@ -6,7 +6,13 @@ mongodb_dir=$(find ${PWD}/ -type d -name "mongodb-linux-x86_64*")
 
 mkdir $mongodb_dir/data
 
-$mongodb_dir/bin/mongod --dbpath $mongodb_dir/data --logpath $mongodb_dir/mongodb.log --fork --replSet mongoengine
+args=(--dbpath $mongodb_dir/data --logpath $mongodb_dir/mongodb.log --fork --replSet mongoengine)
+if (( $(echo "$MONGODB > 3.8" | bc -l) )); then
+    args+=(--setParameter maxTransactionLockRequestTimeoutMillis=1000)
+fi
+
+$mongodb_dir/bin/mongod "${args[@]}"
+
 if (( $(echo "$MONGODB < 6.0" | bc -l) )); then
 mongo --verbose --eval "rs.initiate()"
 mongo --quiet --eval "rs.status().ok"

entrypoint.sh

@@ -3,4 +3,4 @@
 mongod --replSet mongoengine --fork --logpath=/var/log/mongodb.log
 mongo db --eval "rs.initiate()"
 mongod --shutdown
-mongod --replSet mongoengine --bind_ip 0.0.0.0
+mongod --replSet mongoengine --bind_ip 0.0.0.0 --setParameter maxTransactionLockRequestTimeoutMillis=1000

tests/test_context_managers.py

@@ -708,20 +708,30 @@ class B(Document):
         B.drop_collection()
         b_doc = B.objects.create(name="b")
 
-        with pytest.raises(TestRollbackError):
-            with run_in_transaction():
-                a_doc.update(name="trx-parent")
-                try:
-                    with run_in_transaction():
-                        b_doc.update(name="trx-child")
-                        raise TestRollbackError()
-                except TestRollbackError as exc:
-                    # at this stage, the parent transaction is still there
-                    assert A.objects.get(id=a_doc.id).name == "trx-parent"
-                    raise exc
+        def run_tx():
+            try:
+                with run_in_transaction():
+                    a_doc.update(name="trx-parent")
+                    try:
+                        with run_in_transaction():
+                            b_doc.update(name="trx-child")
+                            raise TestRollbackError()
+                    except TestRollbackError as exc:
+                        # at this stage, the parent transaction is still there
+                        assert A.objects.get(id=a_doc.id).name == "trx-parent"
+                        raise exc
+            except OperationError as op_failure:
+                """
+                See thread safety test below for more details about TransientTransactionError handling
+                """
+                if "TransientTransactionError" in str(op_failure):
+                    logging.warning("TransientTransactionError - retrying...")
+                    run_tx()
                 else:
-                    # makes sure it enters the except above
-                    assert False
+                    raise op_failure
+
+        with pytest.raises(TestRollbackError):
+            run_tx()
 
         assert A.objects.get(id=a_doc.id).name == "a"
         assert B.objects.get(id=b_doc.id).name == "b"