Allow model versions to be strings (#197)

* Versions can be strings

* Reformatted

* Fixed some tests

* Minor changes in management library, now check strings to be grouped for invalid characters

* VersionedModelId as a class

* Temporary commit to show hash problem

* Partial fix

* Functional

* Formatted

* Fixup

* Fix failing tests

* Addressed comments

clipper_admin/clipper_manager.py

@@ -431,7 +431,7 @@ def deploy_model(self,
         ----------
         name : str
             The name to assign this model.
-        version : int
+        version : Any object with a string representation (with __str__ implementation)
             The version to assign this model.
         model_data : str or BaseEstimator
             The trained model to add to Clipper. This can either be a
@@ -470,6 +470,7 @@ def deploy_model(self,
                 warn("%s is invalid model format" % str(type(model_data)))
                 return False
 
+            version = str(version)
             vol = "{model_repo}/{name}/{version}".format(
                 model_repo=MODEL_REPO, name=name, version=version)
             # publish model to Clipper and verify success before copying model
@@ -509,13 +510,14 @@ def register_external_model(self,
         ----------
         name : str
             The name to assign this model.
-        version : int
+        version : Any object with a string representation (with __str__ implementation)
             The version to assign this model.
         input_type : str
             One of "integers", "floats", "doubles", "bytes", or "strings".
         labels : list of str, optional
             A list of strings annotating the model.
         """
+        version = str(version)
         return self._publish_new_model(name, version, labels, input_type,
                                        EXTERNALLY_MANAGED_MODEL,
                                        EXTERNALLY_MANAGED_MODEL)
@@ -586,7 +588,7 @@ def deploy_pyspark_model(self,
         ----------
         name : str
             The name to assign this model.
-        version : int
+        version : Any object with a string representation (with __str__ implementation)
             The version to assign this model.
         predict_function : function
             A function that takes three arguments, a SparkContext, the ``model`` parameter and
@@ -679,7 +681,7 @@ def deploy_predict_function(self,
         ----------
         name : str
             The name to assign this model.
-        version : int
+        version : Any object with a string representation (with __str__ implementation)
             The version to assign this model.
         predict_function : function
             The prediction function. Any state associated with the function should be
@@ -766,7 +768,7 @@ def get_model_info(self, model_name, model_version):
         ----------
         model_name : str
             The name of the model to look up
-        model_version : int
+        model_version : Any object with a string representation (with __str__ implementation)
             The version of the model to look up
 
         Returns
@@ -776,6 +778,7 @@ def get_model_info(self, model_name, model_version):
             If no model with name `model_name@model_version` is
             registered with Clipper, None is returned.
         """
+        model_version = str(model_version)
         url = "http://%s:1338/admin/get_model" % self.host
         req_json = json.dumps({
             "model_name": model_name,
@@ -826,7 +829,7 @@ def get_container_info(self, model_name, model_version, replica_id):
         ----------
         model_name : str
             The name of the container to look up
-        model_version : int
+        model_version : Any object with a string representation (with __str__ implementation)
             The version of the container to look up
         replica_id : int
             The container replica to look up
@@ -837,6 +840,7 @@ def get_container_info(self, model_name, model_version, replica_id):
             A dictionary with the specified container's info.
             If no corresponding container is registered with Clipper, None is returned.
         """
+        model_version = str(model_version)
         url = "http://%s:1338/admin/get_container" % self.host
         req_json = json.dumps({
             "model_name": model_name,
@@ -970,7 +974,7 @@ def add_container(self, model_name, model_version):
         ----------
         model_name : str
             The name of the model
-        model_version : int
+        model_version : Any object with a string representation (with __str__ implementation)
             The version of the model
 
         Returns
@@ -979,6 +983,7 @@ def add_container(self, model_name, model_version):
             True if the container was added successfully and False
             if the container could not be added.
         """
+        model_version = str(model_version)
         with hide("warnings", "output", "running"):
             # Look up model info in Redis
             if self.redis_ip == DEFAULT_REDIS_IP:
@@ -1024,7 +1029,7 @@ def add_container(self, model_name, model_version):
                         mv=model_version,
                         mip=model_input_type,
                         clipper_label=CLIPPER_DOCKER_LABEL,
-                        mv_label="%s=%s:%d" % (CLIPPER_MODEL_CONTAINER_LABEL,
+                        mv_label="%s=%s:%s" % (CLIPPER_MODEL_CONTAINER_LABEL,
                                                model_name, model_version),
                         restart_policy=restart_policy))
                 result = self._execute_root(add_container_cmd)
@@ -1101,14 +1106,16 @@ def set_model_version(self, model_name, model_version, num_containers=0):
         ----------
         model_name : str
             The name of the model
-        model_version : int
+        model_version : Any object with a string representation (with __str__ implementation)
             The version of the model. Note that `model_version`
             must be a model version that has already been deployed.
         num_containers : int
             The number of new containers to start with the newly
             selected model version.
 
         """
+        model_version = str(model_version)
+
         url = "http://%s:%d/admin/set_model_version" % (
             self.host, CLIPPER_MANAGEMENT_PORT)
         req_json = json.dumps({

integration-tests/clipper_manager_tests.py

@@ -105,7 +105,7 @@ def test_model_version_sets_correctly(self):
         models_list_contains_correct_version = False
         for model_info in all_models:
             version = model_info["model_version"]
-            if version == self.model_version_1:
+            if version == str(self.model_version_1):
                 models_list_contains_correct_version = True
                 self.assertTrue(model_info["is_current_version"])
 

src/benchmarks/src/end_to_end_bench.cpp

@@ -98,7 +98,7 @@ void send_predictions(
                       cifar_input,
                       100000,
                       clipper::DefaultOutputSelectionPolicy::get_name(),
-                      {std::make_pair(SKLEARN_MODEL_NAME, 1)}});
+                      {VersionedModelId(SKLEARN_MODEL_NAME, "1")}});
       futures.push_back(std::move(future));
     }
 

src/frontends/src/query_frontend.hpp

@@ -178,15 +178,16 @@ class RequestHandler {
               event_type);
           if (event_type == "set") {
             std::string model_name = key;
-            int new_version = clipper::redis::get_current_model_version(
-                redis_connection_, key);
-            if (new_version >= 0) {
+            boost::optional<std::string> new_version =
+                clipper::redis::get_current_model_version(redis_connection_,
+                                                          key);
+            if (new_version) {
               std::unique_lock<std::mutex> l(current_model_versions_mutex_);
-              current_model_versions_[key] = new_version;
+              current_model_versions_[key] = *new_version;
             } else {
               clipper::log_error_formatted(
                   LOGGING_TAG_QUERY_FRONTEND,
-                  "Model version change for model {} was invalid (-1).", key);
+                  "Model version change for model {} was invalid.", key);
             }
           }
         });
@@ -223,18 +224,16 @@ class RequestHandler {
     for (std::string model_name : model_names) {
       auto model_version = clipper::redis::get_current_model_version(
           redis_connection_, model_name);
-      if (model_version >= 0) {
+      if (model_version) {
         std::unique_lock<std::mutex> l(current_model_versions_mutex_);
-        current_model_versions_[model_name] = model_version;
+        current_model_versions_[model_name] = *model_version;
+        model_names_with_version.push_back(model_name + "@" + *model_version);
       } else {
         clipper::log_error_formatted(
             LOGGING_TAG_QUERY_FRONTEND,
-            "Found model {} with invalid version number {}.", model_name,
-            model_version);
-        throw std::runtime_error("Invalid model version number");
+            "Found model {} with missing current version.", model_name);
+        throw std::runtime_error("Invalid model version");
       }
-      model_names_with_version.push_back(model_name + "@v" +
-                                         std::to_string(model_version));
     }
     if (model_names.size() > 0) {
       clipper::log_info_formatted(LOGGING_TAG_QUERY_FRONTEND,
@@ -496,7 +495,7 @@ class RequestHandler {
   /**
    * Returns a copy of the map containing current model names and versions.
    */
-  std::unordered_map<std::string, int> get_current_model_versions() {
+  std::unordered_map<std::string, std::string> get_current_model_versions() {
     return current_model_versions_;
   }
 
@@ -506,7 +505,7 @@ class RequestHandler {
   redox::Redox redis_connection_;
   redox::Subscriber redis_subscriber_;
   std::mutex current_model_versions_mutex_;
-  std::unordered_map<std::string, int> current_model_versions_;
+  std::unordered_map<std::string, std::string> current_model_versions_;
 };
 
 }  // namespace query_frontend

src/frontends/src/query_frontend_tests.cpp

@@ -19,7 +19,7 @@ class MockQueryProcessor {
  public:
   MockQueryProcessor() = default;
   boost::future<Response> predict(Query query) {
-    Response response(query, 3, 5, Output("-1.0", {std::make_pair("m", 1)}),
+    Response response(query, 3, 5, Output("-1.0", {VersionedModelId("m", "1")}),
                       false, boost::optional<std::string>{});
     return boost::make_ready_future(response);
   }
@@ -280,24 +280,25 @@ TEST_F(QueryFrontendTest, TestReadModelsAtStartup) {
   // Add multiple models (some with multiple versions)
   std::vector<std::string> labels{"ads", "images", "experimental", "other",
                                   "labels"};
-  VersionedModelId model1 = std::make_pair("m", 1);
+  VersionedModelId model1 = VersionedModelId("m", "1");
   std::string container_name = "clipper/test_container";
   std::string model_path = "/tmp/models/m/1";
   ASSERT_TRUE(add_model(*redis_, model1, InputType::Ints, labels,
                         container_name, model_path));
-  VersionedModelId model2 = std::make_pair("m", 2);
+  VersionedModelId model2 = VersionedModelId("m", "2");
   std::string model_path2 = "/tmp/models/m/2";
   ASSERT_TRUE(add_model(*redis_, model2, InputType::Ints, labels,
                         container_name, model_path2));
-  VersionedModelId model3 = std::make_pair("n", 3);
+  VersionedModelId model3 = VersionedModelId("n", "3");
   std::string model_path3 = "/tmp/models/n/3";
   ASSERT_TRUE(add_model(*redis_, model3, InputType::Ints, labels,
                         container_name, model_path3));
 
   // Set m@v2 and n@v3 as current model versions
-  set_current_model_version(*redis_, "m", 2);
-  set_current_model_version(*redis_, "n", 3);
-  std::unordered_map<std::string, int> expected_models = {{"m", 2}, {"n", 3}};
+  set_current_model_version(*redis_, "m", "2");
+  set_current_model_version(*redis_, "n", "3");
+  std::unordered_map<std::string, std::string> expected_models = {{"m", "2"},
+                                                                  {"n", "3"}};
 
   RequestHandler<MockQueryProcessor> rh2_("127.0.0.1", 1337, 8);
   EXPECT_EQ(rh2_.get_current_model_versions(), expected_models);
@@ -306,7 +307,7 @@ TEST_F(QueryFrontendTest, TestReadModelsAtStartup) {
 TEST_F(QueryFrontendTest, TestReadInvalidModelVersionAtStartup) {
   std::vector<std::string> labels{"ads", "images", "experimental", "other",
                                   "labels"};
-  VersionedModelId model1 = std::make_pair("m", 1);
+  VersionedModelId model1 = VersionedModelId("m", "1");
   std::string container_name = "clipper/test_container";
   std::string model_path = "/tmp/models/m/1";
   ASSERT_TRUE(add_model(*redis_, model1, InputType::Ints, labels,

src/libclipper/include/clipper/containers.hpp

@@ -84,8 +84,7 @@ class ActiveContainers {
   // A mapping of models to their replicas. The replicas
   // for each model are represented as a map keyed on replica id.
   std::unordered_map<VersionedModelId,
-                     std::map<int, std::shared_ptr<ModelContainer>>,
-                     decltype(&versioned_model_hash)>
+                     std::map<int, std::shared_ptr<ModelContainer>>>
       containers_;
 };
 }

src/libclipper/include/clipper/datatypes.hpp

@@ -6,12 +6,13 @@
 #include <string>
 #include <vector>
 
+#include <boost/functional/hash.hpp>
 #include <boost/optional.hpp>
+#include <boost/thread.hpp>
 
 namespace clipper {
 
 using ByteBuffer = std::vector<uint8_t>;
-using VersionedModelId = std::pair<std::string, int>;
 using QueryId = long;
 using FeedbackAck = bool;
 
@@ -28,11 +29,32 @@ enum class RequestType {
   FeedbackRequest = 1,
 };
 
-size_t versioned_model_hash(const VersionedModelId &key);
-std::string versioned_model_to_str(const VersionedModelId &model);
 std::string get_readable_input_type(InputType type);
 InputType parse_input_type(std::string type_string);
 
+class VersionedModelId {
+ public:
+  VersionedModelId(const std::string name, const std::string id);
+
+  std::string get_name() const;
+  std::string get_id() const;
+  std::string serialize() const;
+  static VersionedModelId deserialize(std::string);
+
+  VersionedModelId(const VersionedModelId &) = default;
+  VersionedModelId &operator=(const VersionedModelId &) = default;
+
+  VersionedModelId(VersionedModelId &&) = default;
+  VersionedModelId &operator=(VersionedModelId &&) = default;
+
+  bool operator==(const VersionedModelId &rhs) const;
+  bool operator!=(const VersionedModelId &rhs) const;
+
+ private:
+  std::string name_;
+  std::string id_;
+};
+
 class Output {
  public:
   Output(const std::string y_hat,
@@ -384,5 +406,16 @@ class PredictionResponse {
 }  // namespace rpc
 
 }  // namespace clipper
-
+namespace std {
+template <>
+struct hash<clipper::VersionedModelId> {
+  typedef std::size_t result_type;
+  std::size_t operator()(const clipper::VersionedModelId &vm) const {
+    std::size_t seed = 0;
+    boost::hash_combine(seed, vm.get_name());
+    boost::hash_combine(seed, vm.get_id());
+    return seed;
+  }
+};
+}
 #endif  // CLIPPER_LIB_DATATYPES_H

src/libclipper/include/clipper/redis.hpp

@@ -21,6 +21,23 @@ namespace redis {
 
 const std::string LOGGING_TAG_REDIS = "REDIS";
 
+/**
+ * Elements of this vector should not appear as substrings of any input Clipper
+ * object value that will be grouped into one entry.
+ * This list should be updated to reflect all delimiters and characters added in
+ * `labels_to_str` or `models_to_str`.
+ */
+const std::vector<std::string> prohibited_group_strings = {
+    ITEM_DELIMITER, ITEM_PART_CONCATENATOR};
+
+/**
+ * Use this function to validate inputs that will be grouped before submitting
+ * them to functions in this library.
+ * @return Whether or not `value` contains any elements of `probhited_strings`
+ * as substrings.
+ */
+bool contains_prohibited_chars_for_group(std::string value);
+
 /**
  * Issues a command to Redis and checks return code.
  * \return Returns true if the command was successful.
@@ -91,10 +108,11 @@ std::string models_to_str(const std::vector<VersionedModelId>& models);
 std::vector<VersionedModelId> str_to_models(const std::string& model_str);
 
 bool set_current_model_version(redox::Redox& redis,
-                               const std::string& model_name, int version);
+                               const std::string& model_name,
+                               const std::string& version);
 
-int get_current_model_version(redox::Redox& redis,
-                              const std::string& model_name);
+boost::optional<std::string> get_current_model_version(
+    redox::Redox& redis, const std::string& model_name);
 
 /**
  * Adds a model into the model table. This will
@@ -142,8 +160,8 @@ std::unordered_map<std::string, std::string> get_model(
  * \return Returns a list of model versions. If the
  * model was not found, an empty list will be returned.
  */
-std::vector<int> get_model_versions(redox::Redox& redis,
-                                    const std::string& model_name);
+std::vector<std::string> get_model_versions(redox::Redox& redis,
+                                            const std::string& model_name);
 
 /**
  * Looks up model names listed in the model table. Since a call to KEYS may

src/libclipper/include/clipper/rpc_service.hpp

@@ -102,8 +102,7 @@ class RPCService {
   std::atomic_bool active_;
   // The next available message id
   int message_id_ = 0;
-  std::unordered_map<VersionedModelId, int, decltype(&versioned_model_hash)>
-      replica_ids_;
+  std::unordered_map<VersionedModelId, int> replica_ids_;
   std::shared_ptr<metrics::Histogram> msg_queueing_hist_;
 
   std::function<void(VersionedModelId, int)> container_ready_callback_;