Cassandra performance enhancement (#521)

* Tech spec

* Tech spec complete

* Cassandra multi-table for performance
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cybermaggedon 2025-09-18 19:52:05 +01:00 committed by GitHub
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4 changed files with 1123 additions and 48 deletions

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@ -534,4 +534,203 @@ class TestCassandraQueryProcessor:
assert len(result) == 2
assert result[0].o.value == 'object1'
assert result[1].o.value == 'object2'
assert result[1].o.value == 'object2'
class TestCassandraQueryPerformanceOptimizations:
"""Test cases for multi-table performance optimizations in query service"""
@pytest.mark.asyncio
@patch('trustgraph.query.triples.cassandra.service.KnowledgeGraph')
async def test_get_po_query_optimization(self, mock_trustgraph):
"""Test that get_po queries use optimized table (no ALLOW FILTERING)"""
from trustgraph.schema import TriplesQueryRequest, Value
mock_tg_instance = MagicMock()
mock_trustgraph.return_value = mock_tg_instance
mock_result = MagicMock()
mock_result.s = 'result_subject'
mock_tg_instance.get_po.return_value = [mock_result]
processor = Processor(taskgroup=MagicMock())
# PO query pattern (predicate + object, find subjects)
query = TriplesQueryRequest(
user='test_user',
collection='test_collection',
s=None,
p=Value(value='test_predicate', is_uri=False),
o=Value(value='test_object', is_uri=False),
limit=50
)
result = await processor.query_triples(query)
# Verify get_po was called (should use optimized po_table)
mock_tg_instance.get_po.assert_called_once_with(
'test_collection', 'test_predicate', 'test_object', limit=50
)
assert len(result) == 1
assert result[0].s.value == 'result_subject'
assert result[0].p.value == 'test_predicate'
assert result[0].o.value == 'test_object'
@pytest.mark.asyncio
@patch('trustgraph.query.triples.cassandra.service.KnowledgeGraph')
async def test_get_os_query_optimization(self, mock_trustgraph):
"""Test that get_os queries use optimized table (no ALLOW FILTERING)"""
from trustgraph.schema import TriplesQueryRequest, Value
mock_tg_instance = MagicMock()
mock_trustgraph.return_value = mock_tg_instance
mock_result = MagicMock()
mock_result.p = 'result_predicate'
mock_tg_instance.get_os.return_value = [mock_result]
processor = Processor(taskgroup=MagicMock())
# OS query pattern (object + subject, find predicates)
query = TriplesQueryRequest(
user='test_user',
collection='test_collection',
s=Value(value='test_subject', is_uri=False),
p=None,
o=Value(value='test_object', is_uri=False),
limit=25
)
result = await processor.query_triples(query)
# Verify get_os was called (should use optimized subject_table with clustering)
mock_tg_instance.get_os.assert_called_once_with(
'test_collection', 'test_object', 'test_subject', limit=25
)
assert len(result) == 1
assert result[0].s.value == 'test_subject'
assert result[0].p.value == 'result_predicate'
assert result[0].o.value == 'test_object'
@pytest.mark.asyncio
@patch('trustgraph.query.triples.cassandra.service.KnowledgeGraph')
async def test_all_query_patterns_use_correct_tables(self, mock_trustgraph):
"""Test that all query patterns route to their optimal tables"""
from trustgraph.schema import TriplesQueryRequest, Value
mock_tg_instance = MagicMock()
mock_trustgraph.return_value = mock_tg_instance
# Mock empty results for all queries
mock_tg_instance.get_all.return_value = []
mock_tg_instance.get_s.return_value = []
mock_tg_instance.get_p.return_value = []
mock_tg_instance.get_o.return_value = []
mock_tg_instance.get_sp.return_value = []
mock_tg_instance.get_po.return_value = []
mock_tg_instance.get_os.return_value = []
mock_tg_instance.get_spo.return_value = []
processor = Processor(taskgroup=MagicMock())
# Test each query pattern
test_patterns = [
# (s, p, o, expected_method)
(None, None, None, 'get_all'), # All triples
('s1', None, None, 'get_s'), # Subject only
(None, 'p1', None, 'get_p'), # Predicate only
(None, None, 'o1', 'get_o'), # Object only
('s1', 'p1', None, 'get_sp'), # Subject + Predicate
(None, 'p1', 'o1', 'get_po'), # Predicate + Object (CRITICAL OPTIMIZATION)
('s1', None, 'o1', 'get_os'), # Object + Subject
('s1', 'p1', 'o1', 'get_spo'), # All three
]
for s, p, o, expected_method in test_patterns:
# Reset mock call counts
mock_tg_instance.reset_mock()
query = TriplesQueryRequest(
user='test_user',
collection='test_collection',
s=Value(value=s, is_uri=False) if s else None,
p=Value(value=p, is_uri=False) if p else None,
o=Value(value=o, is_uri=False) if o else None,
limit=10
)
await processor.query_triples(query)
# Verify the correct method was called
method = getattr(mock_tg_instance, expected_method)
assert method.called, f"Expected {expected_method} to be called for pattern s={s}, p={p}, o={o}"
def test_legacy_vs_optimized_mode_configuration(self):
"""Test that environment variable controls query optimization mode"""
taskgroup_mock = MagicMock()
# Test optimized mode (default)
with patch.dict('os.environ', {}, clear=True):
processor = Processor(taskgroup=taskgroup_mock)
# Mode is determined in KnowledgeGraph initialization
# Test legacy mode
with patch.dict('os.environ', {'CASSANDRA_USE_LEGACY': 'true'}):
processor = Processor(taskgroup=taskgroup_mock)
# Mode is determined in KnowledgeGraph initialization
# Test explicit optimized mode
with patch.dict('os.environ', {'CASSANDRA_USE_LEGACY': 'false'}):
processor = Processor(taskgroup=taskgroup_mock)
# Mode is determined in KnowledgeGraph initialization
@pytest.mark.asyncio
@patch('trustgraph.query.triples.cassandra.service.KnowledgeGraph')
async def test_performance_critical_po_query_no_filtering(self, mock_trustgraph):
"""Test the performance-critical PO query that eliminates ALLOW FILTERING"""
from trustgraph.schema import TriplesQueryRequest, Value
mock_tg_instance = MagicMock()
mock_trustgraph.return_value = mock_tg_instance
# Mock multiple subjects for the same predicate-object pair
mock_results = []
for i in range(5):
mock_result = MagicMock()
mock_result.s = f'subject_{i}'
mock_results.append(mock_result)
mock_tg_instance.get_po.return_value = mock_results
processor = Processor(taskgroup=MagicMock())
# This is the query pattern that was slow with ALLOW FILTERING
query = TriplesQueryRequest(
user='large_dataset_user',
collection='massive_collection',
s=None,
p=Value(value='http://www.w3.org/1999/02/22-rdf-syntax-ns#type', is_uri=True),
o=Value(value='http://example.com/Person', is_uri=True),
limit=1000
)
result = await processor.query_triples(query)
# Verify optimized get_po was used (no ALLOW FILTERING needed!)
mock_tg_instance.get_po.assert_called_once_with(
'massive_collection',
'http://www.w3.org/1999/02/22-rdf-syntax-ns#type',
'http://example.com/Person',
limit=1000
)
# Verify all results were returned
assert len(result) == 5
for i, triple in enumerate(result):
assert triple.s.value == f'subject_{i}'
assert triple.p.value == 'http://www.w3.org/1999/02/22-rdf-syntax-ns#type'
assert triple.p.is_uri is True
assert triple.o.value == 'http://example.com/Person'
assert triple.o.is_uri is True