diff --git a/src/include/aerospike/as_metrics.h b/src/include/aerospike/as_metrics.h
index 33fa08cf2..7c9df3f00 100644
--- a/src/include/aerospike/as_metrics.h
+++ b/src/include/aerospike/as_metrics.h
@@ -78,19 +78,19 @@ typedef struct as_policy_metrics_s {
 
 	struct as_metrics_listeners_s* metrics_listeners;
 
-	FILE* file;
+	void* udata;
 } as_policy_metrics;
 
 struct as_cluster_s;
 struct as_node_s;
 
-typedef void (*as_metrics_enable_callback)(struct as_policy_metrics_s* policy);
+typedef void (*as_metrics_enable_callback)(const struct as_policy_metrics_s* policy);
 
-typedef void (*as_metrics_snapshot_callback)(const struct as_policy_metrics_s* policy, const struct as_cluster_s* cluster);
+typedef void (*as_metrics_snapshot_callback)(const struct as_cluster_s* cluster, void* udata);
 
-typedef void (*as_metrics_node_close_callback)(const struct as_policy_metrics_s* policy, const struct as_node_s* node);
+typedef void (*as_metrics_node_close_callback)(const struct as_node_s* node, void* udata);
 
-typedef void (*as_metrics_disable_callback)(struct as_policy_metrics_s* policy, const struct as_cluster_s* cluster);
+typedef void (*as_metrics_disable_callback)(const struct as_cluster_s* cluster, void* udata);
 
 typedef struct as_metrics_listeners_s {
 	as_metrics_enable_callback enable_callback;
@@ -103,6 +103,22 @@ typedef struct as_node_metrics_s {
 	as_latency_buckets* latency;
 } as_node_metrics;
 
+typedef struct as_metrics_writer_s {
+	FILE* file;
+
+	as_string_builder* sb;
+
+	bool enable;
+
+	uint64_t max_size;
+
+	uint64_t size;
+
+	int32_t latency_columns;
+
+	int32_t latency_shift;
+} as_metrics_writer;
+
 const char* 
 utc_time_str(time_t t);
 
@@ -137,13 +153,16 @@ void
 as_metrics_process_cpu_load_mem_usage(double* cpu_usage, double* mem);
 
 void
-as_metrics_write_cluster(struct as_policy_metrics_s* policy, const struct as_cluster_s* cluster);
+as_metrics_write_cluster(as_metrics_writer* mw, const struct as_cluster_s* cluster);
+
+void
+as_metrics_write_node(as_metrics_writer* mw, struct as_node_stats_s* node_stats);
 
 void
-as_metrics_write_node(as_string_builder* sb, struct as_node_stats_s* node_stats);
+as_metrics_write_conn(as_metrics_writer* mw, struct as_conn_stats_s* conn_stats);
 
 void
-as_metrics_write_conn(as_string_builder* sb, struct as_conn_stats_s* conn_stats);
+as_metrics_write_line(as_metrics_writer* mw);
 
 #if defined(__linux__)
 void
diff --git a/src/include/aerospike/as_node.h b/src/include/aerospike/as_node.h
index 827b77fb2..52661d68d 100644
--- a/src/include/aerospike/as_node.h
+++ b/src/include/aerospike/as_node.h
@@ -298,6 +298,9 @@ typedef struct as_node_s {
 	 */
 	as_racks* racks;
 
+	/**
+	 * Node metrics 
+	 */
 	as_node_metrics* metrics;
 
 	/**
diff --git a/src/main/aerospike/as_cluster.c b/src/main/aerospike/as_cluster.c
index f540db9df..45ec18ec4 100644
--- a/src/main/aerospike/as_cluster.c
+++ b/src/main/aerospike/as_cluster.c
@@ -559,7 +559,7 @@ as_cluster_enable_metrics(as_cluster* cluster, as_policy_metrics* policy)
 {
 	if (cluster->metrics_enabled)
 	{
-		cluster->metrics_listeners->disable_callback(policy, cluster);
+		cluster->metrics_listeners->disable_callback(policy, cluster, policy->udata);
 	}
 
 	cluster->metrics_listeners = policy->metrics_listeners;
@@ -576,7 +576,7 @@ as_cluster_enable_metrics(as_cluster* cluster, as_policy_metrics* policy)
 		as_node_enable_metrics(node, policy);
 	}
 
-	cluster->metrics_listeners->enable_callback(policy);
+	cluster->metrics_listeners->enable_callback(policy, policy->udata);
 }
 
 void
@@ -585,7 +585,7 @@ as_cluster_disable_metrics(as_cluster* cluster)
 	if (cluster->metrics_enabled)
 	{
 		cluster->metrics_enabled = false;
-		cluster->metrics_listeners->disable_callback(cluster->metrics_policy, cluster);
+		cluster->metrics_listeners->disable_callback(cluster->metrics_policy, cluster, cluster->metrics_policy->udata);
 	}
 }
 
@@ -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_listeners->snapshot_callback(cluster->metrics_policy, cluster);
+		cluster->metrics_listeners->snapshot_callback(cluster->metrics_policy, cluster, cluster->metrics_policy->udata);
 	}
 
 	as_cluster_destroy_peers(&peers);
diff --git a/src/main/aerospike/as_metrics.c b/src/main/aerospike/as_metrics.c
index eaa187935..2eb48f7fb 100644
--- a/src/main/aerospike/as_metrics.c
+++ b/src/main/aerospike/as_metrics.c
@@ -45,7 +45,6 @@ as_metrics_policy_init(as_policy_metrics* policy)
 	policy->interval = 30;
 	policy->latency_columns = 7;
 	policy->latency_shift = 1;
-	policy->file = NULL;
 }
 
 char*
@@ -143,7 +142,7 @@ as_metrics_add_latency(as_node_metrics* node_metrics, as_latency_type latency_ty
 }
 
 void 
-as_metrics_enable(struct as_policy_metrics_s* policy)
+as_metrics_writer_enable(const struct as_policy_metrics_s* policy)
 {
 	if (policy->report_size_limit != 0 && policy->report_size_limit < MIN_FILE_SIZE)
 	{
@@ -151,73 +150,79 @@ as_metrics_enable(struct as_policy_metrics_s* policy)
 	}
 
 	// create file directory
-	policy->file = fopen(policy->report_directory, "w");
-
-	as_string_builder sb;
-	as_string_builder_inita(&sb, 25, true);
-	as_string_builder_append(&sb, utc_time_str(time(NULL)));
-	as_string_builder_append(&sb, " header(1)");
-	as_string_builder_append(&sb, " cluster[name,cpu,mem,invalidNodeCount,tranCount,retryCount,delayQueueTimeoutCount,eventloop[],node[]]");
-	as_string_builder_append(&sb, " eventloop[processSize,queueSize]");
-	as_string_builder_append(&sb, " node[name,address,port,syncConn,asyncConn,errors,timeouts,latency[]]");
-	as_string_builder_append(&sb, " conn[inUse,inPool,opened,closed]");
-	as_string_builder_append(&sb, " latency(");
-	as_string_builder_append(&sb, policy->latency_columns);
-	as_string_builder_append(&sb, ',');
-	as_string_builder_append(&sb, policy->latency_shift);
-	as_string_builder_append(&sb, ')');
-	as_string_builder_append(&sb, "[type[l1,l2,l3...]]");
-	fprintf(policy->file, "\n");
-	fprintf(policy->file, sb.data);
+	as_metrics_writer* mw = policy->udata;
+	mw->file = fopen(policy->report_directory, "w");
+	mw->max_size = policy->report_size_limit;
+	mw->latency_columns = policy->latency_columns;
+	mw->latency_shift = policy->latency_shift;
+	mw->size = 0;
+
+	as_string_builder_inita(mw->sb, 25, true);
+	as_string_builder_append(&mw->sb, utc_time_str(time(NULL)));
+	as_string_builder_append(&mw->sb, " header(1)");
+	as_string_builder_append(&mw->sb, " cluster[name,cpu,mem,invalidNodeCount,tranCount,retryCount,delayQueueTimeoutCount,eventloop[],node[]]");
+	as_string_builder_append(&mw->sb, " eventloop[processSize,queueSize]");
+	as_string_builder_append(&mw->sb, " node[name,address,port,syncConn,asyncConn,errors,timeouts,latency[]]");
+	as_string_builder_append(&mw->sb, " conn[inUse,inPool,opened,closed]");
+	as_string_builder_append(&mw->sb, " latency(");
+	as_string_builder_append(&mw->sb, mw->latency_columns);
+	as_string_builder_append(&mw->sb, ',');
+	as_string_builder_append(&mw->sb, mw->latency_shift);
+	as_string_builder_append(&mw->sb, ')');
+	as_string_builder_append(&mw->sb, "[type[l1,l2,l3...]]");
+	as_metrics_write_line(mw);
+
+	mw->enable = true;
 }
 
 void
-as_metrics_snapshot(const struct as_policy_metrics_s* policy, const struct as_cluster_s* cluster)
+as_metrics_writer_snapshot(const struct as_cluster_s* cluster, void* udata)
 {
-	if (policy->file != NULL)
+	as_metrics_writer* mw = udata;
+	if (mw->enable && mw->file != NULL)
 	{
-		as_metrics_write_cluster(policy, cluster);
+		as_metrics_write_cluster(mw, cluster);
 	}
 }
 
 void
-as_metrics_node_close(const struct as_policy_metrics_s* policy, const struct as_node_s* node)
+as_metrics_writer_node_close(const struct as_node_s* node, void* udata)
 {
 	// write node info to file
-	if (policy->file != NULL)
+	as_metrics_writer* mw = udata;
+	if (mw->enable && mw->file != NULL)
 	{
-		as_string_builder sb;
-		as_string_builder_inita(&sb, 25, true);
-		as_string_builder_append(&sb, utc_time_str(time(NULL)));
-		as_metrics_write_node(&sb, node);
-		fprintf(policy->file, "\n");
-		fprintf(policy->file, sb.data);
+		as_string_builder_append(&mw->sb, utc_time_str(time(NULL)));
+		as_metrics_write_node(&mw->sb, node);
+		as_metrics_write_line(mw);
 	}
 }
 
 void
-as_metrics_disable(struct as_policy_metrics_s* policy, const struct as_cluster_s* cluster)
+as_metrics_writer_disable(const struct as_cluster_s* cluster, void* udata)
 {
 	// write cluster into to file, disable
-	if (policy->file != NULL)
+	as_metrics_writer* mw = udata;
+	if (mw->enable && mw->file != NULL)
 	{
-		as_metrics_write_cluster(policy, cluster);
-		fclose(policy->file);
-		policy->file = NULL;
+		as_metrics_write_cluster(mw, cluster);
+		fclose(mw->file);
+		mw->file = NULL;
+		mw->enable = false;
 	}
 }
 
 void
 as_metrics_listeners_init(as_metrics_listeners* listeners)
 {
-	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;
+	listeners->enable_callback = as_metrics_writer_enable;
+	listeners->disable_callback = as_metrics_writer_disable;
+	listeners->node_close_callback = as_metrics_writer_node_close;
+	listeners->snapshot_callback = as_metrics_writer_snapshot;
 }
 
 void
-as_metrics_write_cluster(struct as_policy_metrics_s* policy, const struct as_cluster_s* cluster) {
+as_metrics_write_cluster(as_metrics_writer* mw, const struct as_cluster_s* cluster) {
 	char* cluster_name = cluster->cluster_name;
 	if (cluster_name == NULL)
 	{
@@ -230,78 +235,75 @@ as_metrics_write_cluster(struct as_policy_metrics_s* policy, const struct as_clu
 	as_cluster_stats* stats;
 	aerospike_cluster_stats(cluster, stats);
 
-	as_string_builder sb;
-	as_string_builder_inita(&sb, 10, true);
-	as_string_builder_append(&sb, utc_time_str(time(NULL)));
-	as_string_builder_append(&sb, " cluster[");
-	as_string_builder_append(&sb, cluster_name);
-	as_string_builder_append(&sb, ',');
-	as_string_builder_append(&sb, (int)cpu_load);
-	as_string_builder_append(&sb, ',');
-	as_string_builder_append(&sb, mem);
-	as_string_builder_append(&sb, ',');
-	as_string_builder_append(&sb, cluster->invalid_node_count); // Cumulative. Not reset on each interval.
-	as_string_builder_append(&sb, ',');
-	as_string_builder_append(&sb, as_cluster_get_tran_count(cluster));  // Cumulative. Not reset on each interval.
-	as_string_builder_append(&sb, ',');
-	as_string_builder_append(&sb, cluster->retry_count); // Cumulative. Not reset on each interval.
-	as_string_builder_append(&sb, ',');
-	as_string_builder_append(&sb, cluster->delay_queue_timeout_count); // Cumulative. Not reset on each interval.
-	as_string_builder_append(&sb, ",[");
+	as_string_builder_append(&mw->sb, utc_time_str(time(NULL)));
+	as_string_builder_append(&mw->sb, " cluster[");
+	as_string_builder_append(&mw->sb, cluster_name);
+	as_string_builder_append(&mw->sb, ',');
+	as_string_builder_append(&mw->sb, (int)cpu_load);
+	as_string_builder_append(&mw->sb, ',');
+	as_string_builder_append(&mw->sb, mem);
+	as_string_builder_append(&mw->sb, ',');
+	as_string_builder_append(&mw->sb, cluster->invalid_node_count); // Cumulative. Not reset on each interval.
+	as_string_builder_append(&mw->sb, ',');
+	as_string_builder_append(&mw->sb, as_cluster_get_tran_count(cluster));  // Cumulative. Not reset on each interval.
+	as_string_builder_append(&mw->sb, ',');
+	as_string_builder_append(&mw->sb, cluster->retry_count); // Cumulative. Not reset on each interval.
+	as_string_builder_append(&mw->sb, ',');
+	as_string_builder_append(&mw->sb, cluster->delay_queue_timeout_count); // Cumulative. Not reset on each interval.
+	as_string_builder_append(&mw->sb, ",[");
 
 	as_event_loop_stats* event_loops = stats->event_loops;
 	for (uint32_t i = 0; i < stats->event_loops_size; i++)
 	{
 		as_event_loop_stats* loop = &event_loops[i];
 		if (i > 0) {
-			as_string_builder_append(&sb, ',');
+			as_string_builder_append(&mw->sb, ',');
 		}
-		as_string_builder_append(&sb, '[');
-		as_string_builder_append(&sb, loop->process_size);
-		as_string_builder_append(&sb, ',');
-		as_string_builder_append(&sb, loop->queue_size);
-		as_string_builder_append(&sb, ']');
+		as_string_builder_append(&mw->sb, '[');
+		as_string_builder_append(&mw->sb, loop->process_size);
+		as_string_builder_append(&mw->sb, ',');
+		as_string_builder_append(&mw->sb, loop->queue_size);
+		as_string_builder_append(&mw->sb, ']');
 	}
-	as_string_builder_append(&sb, '],[');
-	
+	as_string_builder_append(&mw->sb, '],[');
+
 	as_node_stats* nodes = stats->nodes;
 	for (uint32_t i = 0; i < stats->nodes_size; i++) {
 		as_node_stats* node = &stats->nodes[i];
 		if (i > 0) {
-			as_string_builder_append(&sb, ",");
+			as_string_builder_append(&mw->sb, ",");
 		}
-		as_metrics_write_node(&sb, node);
+		as_metrics_write_node(&mw->sb, node);
 	}
-	as_string_builder_append(&sb, "]]");
+	as_string_builder_append(&mw->sb, "]]");
 
-	fprintf(policy->file, "\n");
-	fprintf(policy->file, sb.data);
+	as_metrics_write_line(mw);
 }
 
 void
-as_metrics_write_node(as_string_builder* sb, struct as_node_stats_s* node_stats)
+as_metrics_write_node(as_metrics_writer* mw, struct as_node_stats_s* node_stats)
 {
 	as_node* node = node_stats->node;
-	as_string_builder_append(&sb, '[');
-	as_string_builder_append(&sb, node->name);
-	as_string_builder_append(&sb, ',');
+	as_string_builder_append(&mw->sb, '[');
+	as_string_builder_append(&mw->sb, node->name);
+	as_string_builder_append(&mw->sb, ',');
 
 	//as_host* host = node-> TODO: how to get host from node? it is in node_info
 
-	//as_string_builder_append(&sb, host->name);
-	//as_string_builder_append(&sb, ',');
-	//as_string_builder_append(&sb, host->port);
-	//as_string_builder_append(&sb, ',');
+	//as_string_builder_append(&mw->sb, host->name);
+	//as_string_builder_append(&mw->sb, ',');
+	//as_string_builder_append(&mw->sb, host->port);
+	//as_string_builder_append(&mw->sb, ',');
 
-	as_metrics_write_conn(sb, &node_stats->sync);
-	as_string_builder_append(&sb, ',');
-	as_metrics_write_conn(sb, &node_stats->async);
-	as_string_builder_append(&sb, ',');
+	as_metrics_write_conn(&mw->sb, &node_stats->sync);
+	as_string_builder_append(&mw->sb, ',');
+	as_metrics_write_conn(&mw->sb, &node_stats->async);
+	as_string_builder_append(&mw->sb, ',');
 
-	as_string_builder_append(&sb, node->error_count);
-	as_string_builder_append(&sb, ',');
-	as_string_builder_append(&sb, node->timeout_count);
-	as_string_builder_append(&sb, ',[');
+	as_string_builder_append(&mw->sb, node->error_count);
+	as_string_builder_append(&mw->sb, ',');
+	as_string_builder_append(&mw->sb, node->timeout_count);
+	as_string_builder_append(&mw->sb, ',[');
 
 	as_node_metrics* node_metrics = node->metrics;
 	uint32_t max = AS_LATENCY_TYPE_NONE;
@@ -309,35 +311,48 @@ as_metrics_write_node(as_string_builder* sb, struct as_node_stats_s* node_stats)
 
 	for (uint32_t i = 0; i < max; i++) {
 		if (i > 0) {
-			as_string_builder_append(&sb, ",");
+			as_string_builder_append(&mw->sb, ",");
 		}
-		as_string_builder_append(&sb, as_latency_type_to_string(i));
-		as_string_builder_append(&sb, '[');
+		as_string_builder_append(&mw->sb, as_latency_type_to_string(i));
+		as_string_builder_append(&mw->sb, '[');
 
 		as_latency_buckets* buckets = &node_metrics->latency[i];
 		uint32_t bucket_max = buckets->latency_columns;
 
 		for (uint32_t j = 0; j < bucket_max; j++) {
 			if (j > 0) {
-				as_string_builder_append(&sb, ',');
+				as_string_builder_append(&mw->sb, ',');
 			}
-			as_string_builder_append(&sb, as_metrics_get_bucket(&buckets, i));
+			as_string_builder_append(&mw->sb, as_metrics_get_bucket(&buckets, i));
 		}
-		as_string_builder_append(&sb, ']');
+		as_string_builder_append(&mw->sb, ']');
 	}
-	as_string_builder_append(&sb, ']]');
+	as_string_builder_append(&mw->sb, ']]');
 }
 
 void
-as_metrics_write_conn(as_string_builder* sb, struct as_conn_stats_s* conn_stats)
+as_metrics_write_conn(as_metrics_writer* mw, struct as_conn_stats_s* conn_stats)
 {
-	as_string_builder_append(&sb, conn_stats->in_use);
-	as_string_builder_append(&sb, ',');
-	as_string_builder_append(&sb, conn_stats->in_pool);
-	as_string_builder_append(&sb, ',');
-	as_string_builder_append(&sb, conn_stats->opened); // Cumulative. Not reset on each interval.
-	as_string_builder_append(&sb, ',');
-	as_string_builder_append(&sb, conn_stats->closed); // Cumulative. Not reset on each interval.
+	as_string_builder_append(&mw->sb, conn_stats->in_use);
+	as_string_builder_append(&mw->sb, ',');
+	as_string_builder_append(&mw->sb, conn_stats->in_pool);
+	as_string_builder_append(&mw->sb, ',');
+	as_string_builder_append(&mw->sb, conn_stats->opened); // Cumulative. Not reset on each interval.
+	as_string_builder_append(&mw->sb, ',');
+	as_string_builder_append(&mw->sb, conn_stats->closed); // Cumulative. Not reset on each interval.
+}
+
+void
+as_metrics_write_line(as_metrics_writer* mw)
+{
+	as_string_builder_append_newline(&mw->sb);
+	fprintf(mw->file, &mw->sb->data);
+	mw->size += mw->sb->length;
+
+	if (mw->max_size > 0 && mw->size >= mw->max_size)
+	{
+		// write new file?
+	}
 }
 
 #if defined(__linux__)