MG Implementation K-Truss (#4438)

This PR adds an MG implementation of K-Truss leveraging the C API

Authors:
  - Joseph Nke (https://github.com/jnke2016)
  - Ralph Liu (https://github.com/nv-rliu)

Approvers:
  - Chuck Hastings (https://github.com/ChuckHastings)
  - Rick Ratzel (https://github.com/rlratzel)
  - Jake Awe (https://github.com/AyodeAwe)

URL: #4438

python/cugraph/cugraph/community/ktruss_subgraph.py

@@ -11,19 +11,16 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from cugraph.structure.graph_classes import Graph
 from typing import Union
+
+import cudf
+from pylibcugraph import k_truss_subgraph as pylibcugraph_k_truss_subgraph
+from pylibcugraph import ResourceHandle
+from cugraph.structure.graph_classes import Graph
 from cugraph.utilities import (
     ensure_cugraph_obj_for_nx,
     cugraph_to_nx,
 )
-
-from pylibcugraph import k_truss_subgraph as pylibcugraph_k_truss_subgraph
-from pylibcugraph import ResourceHandle
-import warnings
-
-from numba import cuda
-import cudf
 from cugraph.utilities.utils import import_optional
 
 # FIXME: the networkx.Graph type used in the type annotation for
@@ -34,37 +31,17 @@
 networkx = import_optional("networkx")
 
 
-# FIXME: special case for ktruss on CUDA 11.4: an 11.4 bug causes ktruss to
-# crash in that environment. Allow ktruss to import on non-11.4 systems, but
-# raise an exception if ktruss is directly imported on 11.4.
-def _ensure_compatible_cuda_version():
-    try:
-        cuda_version = cuda.runtime.get_version()
-    except cuda.cudadrv.runtime.CudaRuntimeAPIError:
-        cuda_version = "n/a"
-
-    unsupported_cuda_version = (11, 4)
-
-    if cuda_version == unsupported_cuda_version:
-        ver_string = ".".join([str(n) for n in unsupported_cuda_version])
-        raise NotImplementedError(
-            "k_truss is not currently supported in CUDA" f" {ver_string} environments."
-        )
-
-
 def k_truss(
     G: Union[Graph, "networkx.Graph"], k: int
 ) -> Union[Graph, "networkx.Graph"]:
     """
     Returns the K-Truss subgraph of a graph for a specific k.
 
-    NOTE: this function is currently not available on CUDA 11.4 systems.
-
-    The k-truss of a graph is a subgraph where each edge is part of at least
-    (k−2) triangles. K-trusses are used for finding tighlty knit groups of
-    vertices in a graph. A k-truss is a relaxation of a k-clique in the graph
-    and was define in [1]. Finding cliques is computationally demanding and
-    finding the maximal k-clique is known to be NP-Hard.
+    The k-truss of a graph is a subgraph where each edge is incident to at
+    least (k−2) triangles. K-trusses are used for finding tighlty knit groups
+    of vertices in a graph. A k-truss is a relaxation of a k-clique in the graph.
+    Finding cliques is computationally demanding and finding the maximal
+    k-clique is known to be NP-Hard.
 
     Parameters
     ----------
@@ -89,9 +66,6 @@ def k_truss(
     >>> k_subgraph = cugraph.k_truss(G, 3)
 
     """
-
-    _ensure_compatible_cuda_version()
-
     G, isNx = ensure_cugraph_obj_for_nx(G)
 
     if isNx is True:
@@ -159,12 +133,6 @@ def ktruss_subgraph(
     k : int
         The desired k to be used for extracting the k-truss subgraph.
 
-    use_weights : bool, optional (default=True)
-        Whether the output should contain the edge weights if G has them.
-
-        Deprecated: If 'weights' were passed at the graph creation, they will
-        be used.
-
     Returns
     -------
     G_truss : cuGraph.Graph
@@ -177,20 +145,10 @@ def ktruss_subgraph(
     >>> k_subgraph = cugraph.ktruss_subgraph(G, 3, use_weights=False)
     """
 
-    _ensure_compatible_cuda_version()
-
     KTrussSubgraph = Graph()
     if G.is_directed():
         raise ValueError("input graph must be undirected")
 
-    if use_weights:
-        warning_msg = (
-            "The use_weights flag is deprecated "
-            "and will be removed in the next release. if weights "
-            "were passed at the graph creation, they will be used."
-        )
-        warnings.warn(warning_msg, FutureWarning)
-
     sources, destinations, edge_weights, _ = pylibcugraph_k_truss_subgraph(
         resource_handle=ResourceHandle(),
         graph=G._plc_graph,

python/cugraph/cugraph/dask/__init__.py

@@ -23,6 +23,7 @@
 from .community.triangle_count import triangle_count
 from .community.egonet import ego_graph
 from .community.induced_subgraph import induced_subgraph
+from .community.ktruss_subgraph import ktruss_subgraph
 from .centrality.katz_centrality import katz_centrality
 from .components.connectivity import weakly_connected_components
 from .sampling.uniform_neighbor_sample import uniform_neighbor_sample

python/cugraph/cugraph/dask/community/__init__.py

@@ -1,4 +1,4 @@
-# Copyright (c) 2020-2023, NVIDIA CORPORATION.
+# Copyright (c) 2020-2024, NVIDIA CORPORATION.
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
@@ -15,3 +15,4 @@
 from .triangle_count import triangle_count
 from .induced_subgraph import induced_subgraph
 from .leiden import leiden
+from .ktruss_subgraph import ktruss_subgraph

python/cugraph/cugraph/dask/community/ktruss_subgraph.py

@@ -0,0 +1,119 @@
+# Copyright (c) 2024, NVIDIA CORPORATION.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+from typing import Tuple
+
+import cudf
+import cupy as cp
+from dask.distributed import wait, default_client
+import dask_cudf
+
+from pylibcugraph import (
+    ResourceHandle,
+    k_truss_subgraph as pylibcugraph_k_truss_subgraph,
+)
+import cugraph.dask.comms.comms as Comms
+
+
+def _call_k_truss_subgraph(
+    sID: bytes,
+    mg_graph_x,
+    k: int,
+    do_expensive_check: bool,
+) -> Tuple[cp.ndarray, cp.ndarray, cp.ndarray]:
+
+    return pylibcugraph_k_truss_subgraph(
+        resource_handle=ResourceHandle(Comms.get_handle(sID).getHandle()),
+        graph=mg_graph_x,
+        k=k,
+        do_expensive_check=do_expensive_check,
+    )
+
+
+def convert_to_cudf(cp_arrays: cp.ndarray) -> cudf.DataFrame:
+    cp_src, cp_dst, cp_weight, _ = cp_arrays
+
+    df = cudf.DataFrame()
+    if cp_src is not None:
+        df["src"] = cp_src
+        df["dst"] = cp_dst
+    if cp_weight is not None:
+        df["weight"] = cp_weight
+
+    return df
+
+
+def ktruss_subgraph(input_graph, k: int) -> dask_cudf.DataFrame:
+    """
+    Returns the K-Truss subgraph of a graph for a specific k.
+
+    The k-truss of a graph is a subgraph where each edge is incident to at
+    least (k−2) triangles. K-trusses are used for finding tighlty knit groups
+    of vertices in a graph. A k-truss is a relaxation of a k-clique in the graph.
+    Finding cliques is computationally demanding and finding the maximal
+    k-clique is known to be NP-Hard.
+
+    Parameters
+    ----------
+    input_graph : cugraph.Graph
+        Graph or matrix object, which should contain the connectivity
+        information. Edge weights, if present, should be single or double
+        precision floating point values
+
+    k : int
+        The desired k to be used for extracting the k-truss subgraph.
+
+
+    Returns
+    -------
+    k_truss_edge_lists : dask_cudf.DataFrame
+        Distributed GPU data frame containing all source identifiers,
+        destination identifiers, and edge weights belonging to the truss.
+    """
+    if input_graph.is_directed():
+        raise ValueError("input graph must be undirected")
+    # Initialize dask client
+    client = default_client()
+
+    do_expensive_check = False
+
+    result = [
+        client.submit(
+            _call_k_truss_subgraph,
+            Comms.get_session_id(),
+            input_graph._plc_graph[w],
+            k,
+            do_expensive_check,
+            workers=[w],
+            allow_other_workers=False,
+        )
+        for w in Comms.get_workers()
+    ]
+    wait(result)
+
+    cudf_result = [client.submit(convert_to_cudf, cp_arrays) for cp_arrays in result]
+
+    wait(cudf_result)
+
+    ddf = dask_cudf.from_delayed(cudf_result).persist()
+    wait(ddf)
+    # Wait until the inactive futures are released
+    wait([(r.release(), c_r.release()) for r, c_r in zip(result, cudf_result)])
+
+    if input_graph.renumbered:
+        ddf = input_graph.unrenumber(ddf, "src")
+        ddf = input_graph.unrenumber(ddf, "dst")
+
+    return ddf

python/cugraph/cugraph/tests/community/test_k_truss_subgraph.py

@@ -20,7 +20,6 @@
 import cugraph
 from cugraph.testing import utils
 from cugraph.datasets import polbooks, karate_asymmetric
-from numba import cuda
 
 
 # =============================================================================
@@ -67,32 +66,7 @@ def compare_k_truss(k_truss_cugraph, k, ground_truth_file):
     return True
 
 
-__cuda_version = cuda.runtime.get_version()
-__unsupported_cuda_version = (11, 4)
-
-
-# FIXME: remove when ktruss is supported on CUDA 11.4
-@pytest.mark.sg
-def test_unsupported_cuda_version():
-    """
-    Ensures the proper exception is raised when ktruss is called in an
-    unsupported env, and not when called in a supported env.
-    """
-    k = 5
-
-    G = polbooks.get_graph(download=True)
-    if __cuda_version == __unsupported_cuda_version:
-        with pytest.raises(NotImplementedError):
-            cugraph.k_truss(G, k)
-    else:
-        cugraph.k_truss(G, k)
-
-
 @pytest.mark.sg
-@pytest.mark.skipif(
-    (__cuda_version == __unsupported_cuda_version),
-    reason="skipping on unsupported CUDA " f"{__unsupported_cuda_version} environment.",
-)
 @pytest.mark.parametrize("_, nx_ground_truth", utils.DATASETS_KTRUSS)
 def test_ktruss_subgraph_Graph(_, nx_ground_truth):
 
@@ -104,10 +78,6 @@ def test_ktruss_subgraph_Graph(_, nx_ground_truth):
 
 
 @pytest.mark.sg
-@pytest.mark.skipif(
-    (__cuda_version == __unsupported_cuda_version),
-    reason="skipping on unsupported CUDA " f"{__unsupported_cuda_version} environment.",
-)
 def test_ktruss_subgraph_Graph_nx():
     k = 5
     dataset_path = polbooks.get_path()
@@ -122,10 +92,6 @@ def test_ktruss_subgraph_Graph_nx():
 
 
 @pytest.mark.sg
-@pytest.mark.skipif(
-    (__cuda_version == __unsupported_cuda_version),
-    reason="skipping on unsupported CUDA " f"{__unsupported_cuda_version} environment.",
-)
 def test_ktruss_subgraph_directed_Graph():
     k = 5
     edgevals = True