Dynamic memory cleanup for MongoDB exporting connector (#9103)

2 files changed, 80 insertions, 46 deletions

diff --git a/exporting/exporting_engine.c b/exporting/exporting_engine.c
index 656e5ada78..17f2327c4d 100644
--- a/exporting/exporting_engine.c
+++ b/exporting/exporting_engine.c
@@ -30,6 +30,7 @@ static void exporting_main_cleanup(void *ptr)
         if (!instance->exited) {
             found++;
             info("stopping worker for instance %s", instance->config.name);
+            uv_mutex_unlock(&instance->mutex);
             uv_cond_signal(&instance->cond_var);
         } else
             info("found stopped worker for instance %s", instance->config.name);
diff --git a/exporting/mongodb/mongodb.c b/exporting/mongodb/mongodb.c
index f20c4f1c80..38e1d01378 100644
--- a/exporting/mongodb/mongodb.c
+++ b/exporting/mongodb/mongodb.c
@@ -80,22 +80,6 @@ int mongodb_init(struct instance *instance)
 }
 
 /**
- * Clean a MongoDB connector instance up
- *
- * @param instance an instance data structure.
- */
-void mongodb_cleanup(struct instance *instance)
-{
-    struct mongodb_specific_data *connector_specific_data =
-        (struct mongodb_specific_data *)instance->connector_specific_data;
-
-    mongoc_collection_destroy(connector_specific_data->collection);
-    mongoc_client_destroy(connector_specific_data->client);
-
-    return;
-}
-
-/**
  * Initialize a MongoDB connector instance
  *
  * @param instance an instance data structure.
@@ -238,6 +222,51 @@ int format_batch_mongodb(struct instance *instance)
 }
 
 /**
+ * Clean a MongoDB connector instance up
+ *
+ * @param instance an instance data structure.
+ */
+void mongodb_cleanup(struct instance *instance)
+{
+    info("EXPORTING: cleaning up instance %s ...", instance->config.name);
+
+    struct mongodb_specific_data *connector_specific_data =
+        (struct mongodb_specific_data *)instance->connector_specific_data;
+
+    mongoc_collection_destroy(connector_specific_data->collection);
+    mongoc_client_destroy(connector_specific_data->client);
+    if (instance->engine->mongoc_initialized) {
+        mongoc_cleanup();
+        instance->engine->mongoc_initialized = 0;
+    }
+
+    buffer_free(instance->buffer);
+
+    struct bson_buffer *next_buffer = connector_specific_data->first_buffer;
+    for (int i = 0; i < instance->config.buffer_on_failures; i++) {
+        struct bson_buffer *current_buffer = next_buffer;
+        next_buffer = next_buffer->next;
+
+        if (current_buffer->insert)
+            free_bson(current_buffer->insert, current_buffer->documents_inserted);
+        freez(current_buffer);
+    }
+
+    freez(connector_specific_data);
+
+    struct mongodb_specific_config *connector_specific_config =
+        (struct mongodb_specific_config *)instance->config.connector_specific_config;
+    freez(connector_specific_config->database);
+    freez(connector_specific_config->collection);
+    freez(connector_specific_config);
+
+    info("EXPORTING: instance %s exited", instance->config.name);
+    instance->exited = 1;
+
+    return;
+}
+
+/**
  * MongoDB connector worker
  *
  * Runs in a separate thread for every instance.
@@ -251,12 +280,17 @@ void mongodb_connector_worker(void *instance_p)
     struct mongodb_specific_data *connector_specific_data =
         (struct mongodb_specific_data *)instance->connector_specific_data;
 
-    while (!netdata_exit) {
+    while (!instance->engine->exit) {
         struct stats *stats = &instance->stats;
 
         uv_mutex_lock(&instance->mutex);
         uv_cond_wait(&instance->cond_var, &instance->mutex);
 
+        if (unlikely(instance->engine->exit)) {
+            uv_mutex_unlock(&instance->mutex);
+            break;
+        }
+
         // reset the monitoring chart counters
         stats->received_bytes =
         stats->sent_bytes =
@@ -293,38 +327,37 @@ void mongodb_connector_worker(void *instance_p)
             connector_specific_config->collection,
             data_size);
 
-        if (unlikely(documents_inserted == 0))
-            continue;
-
-        bson_error_t bson_error;
-        if (likely(mongoc_collection_insert_many(
-                connector_specific_data->collection,
-                (const bson_t **)insert,
-                documents_inserted,
-                NULL,
-                NULL,
-                &bson_error))) {
-            stats->sent_metrics = documents_inserted;
-            stats->sent_bytes += data_size;
-            stats->transmission_successes++;
-            stats->receptions++;
-        } else {
-            // oops! we couldn't send (all or some of the) data
-            error("EXPORTING: %s", bson_error.message);
-            error(
-                "EXPORTING: failed to write data to the database '%s'. "
-                "Willing to write %zu bytes, wrote %zu bytes.",
-                instance->config.destination, data_size, 0UL);
-
-            stats->transmission_failures++;
-            stats->data_lost_events++;
-            stats->lost_bytes += buffered_bytes;
-            stats->lost_metrics += documents_inserted;
+        if (likely(documents_inserted != 0)) {
+            bson_error_t bson_error;
+            if (likely(mongoc_collection_insert_many(
+                    connector_specific_data->collection,
+                    (const bson_t **)insert,
+                    documents_inserted,
+                    NULL,
+                    NULL,
+                    &bson_error))) {
+                stats->sent_metrics = documents_inserted;
+                stats->sent_bytes += data_size;
+                stats->transmission_successes++;
+                stats->receptions++;
+            } else {
+                // oops! we couldn't send (all or some of the) data
+                error("EXPORTING: %s", bson_error.message);
+                error(
+                    "EXPORTING: failed to write data to the database '%s'. "
+                    "Willing to write %zu bytes, wrote %zu bytes.",
+                    instance->config.destination, data_size, 0UL);
+
+                stats->transmission_failures++;
+                stats->data_lost_events++;
+                stats->lost_bytes += buffered_bytes;
+                stats->lost_metrics += documents_inserted;
+            }
         }
 
         free_bson(insert, documents_inserted);
 
-        if (unlikely(netdata_exit))
+        if (unlikely(instance->engine->exit))
             break;
 
         uv_mutex_lock(&instance->mutex);
@@ -341,7 +374,7 @@ void mongodb_connector_worker(void *instance_p)
         uv_mutex_unlock(&instance->mutex);
 
 #ifdef UNIT_TESTING
-        break;
+        return;
 #endif
     }