feat(axiom): Update datastore handling to support DynamoDb

* add db.system
* modify datastore to allow for datastore that don't have concept of database name

Author: zsistla

axiom/nr_datastore.h

@@ -32,6 +32,7 @@ typedef enum {
   NR_DATASTORE_SYBASE,
   NR_DATASTORE_INFORMIX,
   NR_DATASTORE_PDO,
+  NR_DATASTORE_DYNAMODB,
   NR_DATASTORE_MUST_BE_LAST
 } nr_datastore_t;
 

axiom/nr_datastore_private.h

@@ -32,6 +32,7 @@ static const nr_datastore_mapping_t datastore_mappings[] = {
     {NR_DATASTORE_SYBASE, "Sybase", "sybase", 1},
     {NR_DATASTORE_INFORMIX, "Informix", "informix", 1},
     {NR_DATASTORE_PDO, "PDO", "pdo", 0},
+    {NR_DATASTORE_DYNAMODB, "DynamoDB", "dynamodb", 0},
     {NR_DATASTORE_MUST_BE_LAST, NULL, NULL, 0},
 };
 static size_t datastore_mappings_len

axiom/nr_segment.c

@@ -262,6 +262,9 @@ static void nr_populate_datastore_spans(nr_span_event_t* span_event,
   nr_span_event_set_datastore(span_event, NR_SPAN_DATASTORE_COMPONENT,
                               component);
 
+  nr_span_event_set_datastore(span_event, NR_SPAN_DATASTORE_DB_SYSTEM,
+                              segment->typed_attributes->datastore.db_system);                            
+
   host = segment->typed_attributes->datastore.instance.host;
   nr_span_event_set_datastore(span_event, NR_SPAN_DATASTORE_PEER_HOSTNAME,
                               host);
@@ -595,6 +598,7 @@ bool nr_segment_set_datastore(nr_segment_t* segment,
       .input_query_json = datastore->input_query_json ? nr_strdup(datastore->input_query_json) : NULL,
       .backtrace_json = datastore->backtrace_json ? nr_strdup(datastore->backtrace_json) : NULL,
       .explain_plan_json = datastore->explain_plan_json ? nr_strdup(datastore->explain_plan_json) : NULL,
+      .db_system = datastore->db_system ? nr_strdup(datastore->db_system) : NULL,
   };
 
   segment->typed_attributes->datastore.instance = (nr_datastore_instance_t){

axiom/nr_segment.h

@@ -99,6 +99,7 @@ typedef struct _nr_segment_datastore_t {
   char* input_query_json;
   char* backtrace_json;
   char* explain_plan_json;
+  char* db_system;
   nr_datastore_instance_t instance;
 } nr_segment_datastore_t;
 

axiom/nr_segment_datastore.c

@@ -15,6 +15,7 @@
 static char* create_metrics(nr_segment_t* segment,
                             nrtime_t duration,
                             const char* product,
+                            nr_datastore_t type,
                             const char* collection,
                             const char* operation,
                             nr_segment_datastore_t* datastore,
@@ -59,12 +60,23 @@ static char* create_metrics(nr_segment_t* segment,
   }
 
   if (txn->options.database_name_reporting_enabled) {
-    nr_datastore_instance_set_database_name(&datastore->instance,
-                                            instance->database_name);
+    /*
+     * According the agent-specs Datastore-Metrics-PORTED.md:
+     * There are datastores that do not have the notion of a database name and
+     * they are exempt from collecting it. The following list recognizes
+     * datastores for which a database name is not applicable. DynamoDb is one
+     * such case and as such the db.instance attribute should not be set.
+     */
+
+    if (NR_DATASTORE_DYNAMODB != type) {
+      nr_datastore_instance_set_database_name(&datastore->instance,
+                                              instance->database_name);
+    }
   }
 
   instance_metric = nr_formatf("Datastore/instance/%s/%s/%s", product,
                                instance->host, instance->port_path_or_id);
+
   nr_segment_add_metric(segment, instance_metric, false);
   nr_datastore_instance_set_host(&datastore->instance, instance->host);
   nr_datastore_instance_set_port_path_or_id(&datastore->instance,
@@ -208,9 +220,9 @@ bool nr_segment_datastore_end(nr_segment_t** segment_ptr,
    * The allWeb and allOther rollup metrics are created at the end of the
    * transaction since the background status may change.
    */
-  scoped_metric
-      = create_metrics(segment, duration, datastore_string, collection,
-                       operation, &datastore, params->instance);
+  scoped_metric = create_metrics(segment, duration, datastore_string,
+                                 params->datastore.type, collection, operation,
+                                 &datastore, params->instance);
 
   nr_segment_set_name(segment, scoped_metric);
 
@@ -256,8 +268,8 @@ bool nr_segment_datastore_end(nr_segment_t** segment_ptr,
         break;
     }
   }
-
   datastore.component = nr_strdup(datastore_string);
+  datastore.db_system = params->db_system;
 
   if (input_query) {
     nrobj_t* obj = nro_new_hash();

axiom/nr_segment_datastore.h

@@ -22,6 +22,7 @@ typedef struct _nr_segment_datastore_params_t {
                        extracted from the SQL for SQL segments. */
   char* operation;  /* The null-terminated operation; if NULL, this will be
                        extracted from the SQL for SQL segments. */
+  char* db_system;  /* Database management system (DBMS) product being used.*/
   nr_datastore_instance_t*
       instance; /* Any instance information that was collected. */
 

axiom/nr_segment_private.c

@@ -23,6 +23,7 @@ void nr_segment_datastore_destroy_fields(nr_segment_datastore_t* datastore) {
   nr_free(datastore->input_query_json);
   nr_free(datastore->backtrace_json);
   nr_free(datastore->explain_plan_json);
+  nr_free(datastore->db_system);
   nr_free(datastore->instance.host);
   nr_free(datastore->instance.port_path_or_id);
   nr_free(datastore->instance.database_name);

axiom/nr_span_event.c

@@ -312,6 +312,9 @@ void nr_span_event_set_datastore(nr_span_event_t* event,
     case NR_SPAN_DATASTORE_COMPONENT:
       nro_set_hash_string(event->intrinsics, "component", new_value);
       break;
+    case NR_SPAN_DATASTORE_DB_SYSTEM:
+      nro_set_hash_string(event->agent_attributes, "db.system", new_value);
+      break;
     case NR_SPAN_DATASTORE_DB_STATEMENT:
       nro_set_hash_string(event->agent_attributes, "db.statement", new_value);
       break;
@@ -525,6 +528,8 @@ const char* nr_span_event_get_datastore(
   switch (member) {
     case NR_SPAN_DATASTORE_COMPONENT:
       return nro_get_hash_string(event->intrinsics, "component", NULL);
+    case NR_SPAN_DATASTORE_DB_SYSTEM:
+      return nro_get_hash_string(event->agent_attributes, "db.system", NULL);
     case NR_SPAN_DATASTORE_DB_STATEMENT:
       return nro_get_hash_string(event->agent_attributes, "db.statement", NULL);
     case NR_SPAN_DATASTORE_DB_INSTANCE:

axiom/nr_span_event.h

@@ -67,7 +67,8 @@ typedef enum {
   NR_SPAN_DATASTORE_DB_STATEMENT,
   NR_SPAN_DATASTORE_DB_INSTANCE,
   NR_SPAN_DATASTORE_PEER_ADDRESS,
-  NR_SPAN_DATASTORE_PEER_HOSTNAME
+  NR_SPAN_DATASTORE_PEER_HOSTNAME,
+  NR_SPAN_DATASTORE_DB_SYSTEM
 } nr_span_event_datastore_member_t;
 
 /*

axiom/tests/test_span_event.c

@@ -432,6 +432,23 @@ static void test_span_event_datastore_string_get_and_set(void) {
       "set db_statement to rabbit", "rabbit",
       nr_span_event_get_datastore(event, NR_SPAN_DATASTORE_PEER_HOSTNAME));
 
+  // Test : setting and getting db.system
+  tlib_pass_if_null(
+      "if unset, the db.system should be NULL",
+      nr_span_event_get_datastore(event, NR_SPAN_DATASTORE_DB_SYSTEM));
+  nr_span_event_set_datastore(event, NR_SPAN_DATASTORE_DB_SYSTEM, NULL);
+  tlib_pass_if_null(
+      "if passed NULL, the db.system should be NULL",
+      nr_span_event_get_datastore(event, NR_SPAN_DATASTORE_DB_SYSTEM));
+  nr_span_event_set_datastore(event, NR_SPAN_DATASTORE_DB_SYSTEM, "wombat");
+  tlib_pass_if_str_equal(
+      "set db.system to wombat", "wombat",
+      nr_span_event_get_datastore(event, NR_SPAN_DATASTORE_DB_SYSTEM));
+  nr_span_event_set_datastore(event, NR_SPAN_DATASTORE_DB_SYSTEM, "rabbit");
+  tlib_pass_if_str_equal(
+      "set db.system to rabbit", "rabbit",
+      nr_span_event_get_datastore(event, NR_SPAN_DATASTORE_DB_SYSTEM));
+
   nr_span_event_destroy(&event);
 }