diff --git a/src/include/aerospike/as_cluster.h b/src/include/aerospike/as_cluster.h
index 41990c23a..626eaf919 100644
--- a/src/include/aerospike/as_cluster.h
+++ b/src/include/aerospike/as_cluster.h
@@ -385,7 +385,7 @@ typedef struct as_cluster_s {
 
 	as_policy_metrics* metrics_policy;
 
-	as_metrics_callbacks* metrics_callbacks;
+	as_metrics_listeners* metrics_listeners;
 
 	uint64_t retry_count;
 
@@ -532,15 +532,31 @@ as_partition_shm_get_node(
 	as_node* prev_node, as_policy_replica replica, uint8_t replica_size, uint8_t* replica_index
 	);
 
+/**
+ * @private
+ * Enable the collection of metrics
+ */
 void
 as_cluster_enable_metrics(as_cluster* cluster, as_policy_metrics* policy);
 
+/**
+ * @private
+ * Disable the collection of metrics
+ */
 void
 as_cluster_disable_metrics(as_cluster* cluster);
 
+/**
+ * @private
+ * Increment transaction count when metrics are enabled.
+ */
 void 
 as_cluster_add_tran(as_cluster* cluster);
 
+/**
+ * @private
+ * Return transaction count. The value is cumulative and not reset per metrics interval.
+ */
 uint64_t
 as_cluster_get_tran_count(const as_cluster* cluster);
 
@@ -573,7 +589,7 @@ static inline void
 as_node_incr_error_rate(as_node* node)
 {
 	if (node->cluster->max_error_rate > 0) {
-		as_incr_uint32(&node->error_rate_count);
+		as_incr_uint32(&node->error_rate);
 	}
 }
 
@@ -582,9 +598,9 @@ as_node_incr_error_rate(as_node* node)
  * Reset node's error count.
  */
 static inline void
-as_node_reset_error_rate_count(as_node* node)
+as_node_reset_error_rate(as_node* node)
 {
-	as_store_uint32(&node->error_rate_count, 0);
+	as_store_uint32(&node->error_rate, 0);
 }
 
 /**
@@ -594,7 +610,7 @@ as_node_reset_error_rate_count(as_node* node)
 static inline uint32_t
 as_node_get_error_rate(as_node* node)
 {
-	return as_load_uint32(&node->error_rate_count);
+	return as_load_uint32(&node->error_rate);
 }
 
 /**
@@ -605,7 +621,7 @@ static inline bool
 as_node_valid_error_rate(as_node* node)
 {
 	uint32_t max = node->cluster->max_error_rate;
-	return max == 0 || max >= as_load_uint32(&node->error_rate_count);
+	return max == 0 || max >= as_load_uint32(&node->error_rate);
 }
 
 /**
diff --git a/src/include/aerospike/as_metrics.h b/src/include/aerospike/as_metrics.h
index c980eb5db..986dc40c2 100644
--- a/src/include/aerospike/as_metrics.h
+++ b/src/include/aerospike/as_metrics.h
@@ -39,19 +39,19 @@ extern "C" {
 #define MIN_FILE_SIZE 1000000
 #define UTC_STR_LEN 72
 
+typedef uint8_t as_latency_type;
+
+#define AS_LATENCY_TYPE_CONN 0
+#define AS_LATENCY_TYPE_WRITE 1
+#define AS_LATENCY_TYPE_READ 2
+#define AS_LATENCY_TYPE_BATCH 3
+#define AS_LATENCY_TYPE_QUERY 4
+#define AS_LATENCY_TYPE_NONE 5
+
 /******************************************************************************
  * TYPES
  *****************************************************************************/
 
-typedef enum as_latency_type_e {
-	AS_LATENCY_TYPE_CONN, //as_queue or as_async_conn_pool?
-	AS_LATENCY_TYPE_WRITE,
-	AS_LATENCY_TYPE_READ,
-	AS_LATENCY_TYPE_BATCH,
-	AS_LATENCY_TYPE_QUERY,
-	AS_LATENCY_TYPE_NONE
-} as_latency_type;
-
 typedef struct as_latency_buckets_s {
 	int32_t latency_shift;
 
@@ -60,7 +60,7 @@ typedef struct as_latency_buckets_s {
 	uint64_t* buckets;
 } as_latency_buckets;
 
-struct as_metrics_callbacks_s;
+struct as_metrics_listeners_s;
 
 /**
 * Metrics Policy
@@ -76,7 +76,7 @@ typedef struct as_policy_metrics_s {
 
 	int32_t latency_shift; // default 1
 
-	struct as_metrics_callbacks_s* metrics_callbacks;
+	struct as_metrics_listeners_s* metrics_listeners;
 
 	FILE* file;
 } as_policy_metrics;
@@ -92,12 +92,12 @@ typedef void (*as_metrics_node_close_callback)(const struct as_policy_metrics_s*
 
 typedef void (*as_metrics_disable_callback)(struct as_policy_metrics_s* policy, const struct as_cluster_s* cluster);
 
-typedef struct as_metrics_callbacks_s {
+typedef struct as_metrics_listeners_s {
 	as_metrics_enable_callback enable_callback;
 	as_metrics_snapshot_callback snapshot_callback;
 	as_metrics_node_close_callback node_close_callback;
 	as_metrics_disable_callback disable_callback;
-} as_metrics_callbacks;
+} as_metrics_listeners;
 
 typedef struct as_node_metrics_s {
 	as_latency_buckets* latency;
@@ -131,7 +131,7 @@ void
 as_metrics_add_latency(as_node_metrics* node_metrics, as_latency_type latency_type, uint64_t elapsed);
 
 void
-as_metrics_callbacks_init(as_metrics_callbacks* callbacks);
+as_metrics_listeners_init(as_metrics_listeners* listeners);
 
 void
 as_metrics_process_cpu_load_mem_usage(double* cpu_usage, double* mem);
diff --git a/src/include/aerospike/as_node.h b/src/include/aerospike/as_node.h
index 8033e4985..827b77fb2 100644
--- a/src/include/aerospike/as_node.h
+++ b/src/include/aerospike/as_node.h
@@ -323,10 +323,18 @@ typedef struct as_node_s {
 	/**
 	 * Error count for this node's error_rate_window.
 	 */
-	uint32_t error_rate_count;
+	uint32_t error_rate;
 
+	/**
+     * Transaction error count since node was initialized. If the error is retryable, multiple errors per
+     * transaction may occur.
+     */
 	uint64_t error_count;
 
+	/**
+	 * Transaction timeout count since node was initialized. If the timeout is retryable (ie socketTimeout),
+	 * multiple timeouts per transaction may occur.
+	 */
 	uint64_t timeout_count;
 
 	/**
@@ -644,8 +652,6 @@ as_node_signal_login(as_node* node);
 bool
 as_node_has_rack(as_node* node, const char* ns, int rack_id);
 
-typedef enum as_latency_type_e as_latency_type;
-
 void
 as_node_add_latency(as_node* node, as_latency_type latency_type, uint64_t elapsed);
 
diff --git a/src/main/aerospike/as_cluster.c b/src/main/aerospike/as_cluster.c
index be378b1e3..f540db9df 100644
--- a/src/main/aerospike/as_cluster.c
+++ b/src/main/aerospike/as_cluster.c
@@ -559,13 +559,13 @@ as_cluster_enable_metrics(as_cluster* cluster, as_policy_metrics* policy)
 {
 	if (cluster->metrics_enabled)
 	{
-		cluster->metrics_callbacks->disable_callback(policy, cluster);
+		cluster->metrics_listeners->disable_callback(policy, cluster);
 	}
 
-	cluster->metrics_callbacks = policy->metrics_callbacks;
-	if (cluster->metrics_callbacks == NULL)
+	cluster->metrics_listeners = policy->metrics_listeners;
+	if (cluster->metrics_listeners == NULL)
 	{
-		as_metrics_callbacks_init(cluster->metrics_callbacks);
+		as_metrics_listeners_init(cluster->metrics_listeners);
 	}
 
 	cluster->metrics_policy = policy;
@@ -576,7 +576,7 @@ as_cluster_enable_metrics(as_cluster* cluster, as_policy_metrics* policy)
 		as_node_enable_metrics(node, policy);
 	}
 
-	cluster->metrics_callbacks->enable_callback(policy);
+	cluster->metrics_listeners->enable_callback(policy);
 }
 
 void
@@ -585,7 +585,7 @@ as_cluster_disable_metrics(as_cluster* cluster)
 	if (cluster->metrics_enabled)
 	{
 		cluster->metrics_enabled = false;
-		cluster->metrics_callbacks->disable_callback(cluster->metrics_policy, cluster);
+		cluster->metrics_listeners->disable_callback(cluster->metrics_policy, cluster);
 	}
 }
 
@@ -647,7 +647,7 @@ as_cluster_remove_nodes(as_cluster* cluster, as_vector* /* <as_node*> */ nodes_t
 		as_node_deactivate(node);
 
 		if (cluster->metrics_enabled) {
-			cluster->metrics_callbacks->node_close_callback(node->cluster->metrics_policy, node);
+			cluster->metrics_listeners->node_close_callback(node->cluster->metrics_policy, node);
 		}
 	}
 			
@@ -724,7 +724,7 @@ as_cluster_reset_error_rate(as_cluster* cluster)
 	as_nodes* nodes = cluster->nodes;
 
 	for (uint32_t i = 0; i < nodes->size; i++) {
-		as_node_reset_error_rate_count(nodes->array[i]);
+		as_node_reset_error_rate(nodes->array[i]);
 	}
 }
 
@@ -968,7 +968,7 @@ as_cluster_tend(as_cluster* cluster, as_error* err, bool is_init)
 
 	if (cluster->metrics_enabled && (cluster->tend_count % cluster->metrics_policy->interval))
 	{
-		cluster->metrics_callbacks->snapshot_callback(cluster->metrics_policy, cluster);
+		cluster->metrics_listeners->snapshot_callback(cluster->metrics_policy, cluster);
 	}
 
 	as_cluster_destroy_peers(&peers);
diff --git a/src/main/aerospike/as_metrics.c b/src/main/aerospike/as_metrics.c
index 5fdb07546..435c1e4aa 100644
--- a/src/main/aerospike/as_metrics.c
+++ b/src/main/aerospike/as_metrics.c
@@ -208,12 +208,12 @@ as_metrics_disable(struct as_policy_metrics_s* policy, const struct as_cluster_s
 }
 
 void
-as_metrics_callbacks_init(as_metrics_callbacks* callbacks)
+as_metrics_listeners_init(as_metrics_listeners* listeners)
 {
-	callbacks->enable_callback = as_metrics_enable;
-	callbacks->disable_callback = as_metrics_disable;
-	callbacks->node_close_callback = as_metrics_node_close;
-	callbacks->snapshot_callback = as_metrics_snapshot;
+	listeners->enable_callback = as_metrics_enable;
+	listeners->disable_callback = as_metrics_disable;
+	listeners->node_close_callback = as_metrics_node_close;
+	listeners->snapshot_callback = as_metrics_snapshot;
 }
 
 void
diff --git a/src/main/aerospike/as_node.c b/src/main/aerospike/as_node.c
index 7c841c603..01d55a897 100644
--- a/src/main/aerospike/as_node.c
+++ b/src/main/aerospike/as_node.c
@@ -145,7 +145,7 @@ as_node_create(as_cluster* cluster, as_node_info* node_info)
 	node->sync_conn_pools = cf_malloc(sizeof(as_conn_pool) * cluster->conn_pools_per_node);
 	node->sync_conns_opened = 1;
 	node->sync_conns_closed = 0;
-	node->error_rate_count = 0;
+	node->error_rate = 0;
 	node->error_count = 0;
 	node->timeout_count = 0;
 	node->conn_iter = 0;
@@ -909,7 +909,7 @@ static void
 as_node_restart(as_cluster* cluster, as_node* node)
 {
 	if (cluster->max_error_rate > 0) {
-		as_node_reset_error_rate_count(node);
+		as_node_reset_error_rate(node);
 	}
 
 	// Balance sync connections.