feature: save application metrics to db for alerting

includes/common.php

@@ -1866,3 +1866,15 @@ function check_file_permissions($file, $mask)
 
     return ($perms & $mask) === $mask;
 }
+
+/**
+ * Index an array by a column
+ *
+ * @param array $array
+ * @param string|int $column
+ * @return array
+ */
+function array_by_column($array, $column)
+{
+    return array_combine(array_column($array, $column), $array);
+}

includes/dbFacile.php

@@ -292,6 +292,33 @@ function dbDelete($table, $where = null, $parameters = array())
 }//end dbDelete()
 
 
+/**
+ * Delete orphaned entries from a table that no longer have a parent in parent_table
+ *
+ * @param string $parent_table
+ * @param string $child_table
+ * @param string $id_column
+ * @return bool|int
+ */
+function dbDeleteOrphans($parent_table, $child_table, $id_column)
+{
+    global $database_link;
+    $time_start = microtime(true);
+
+    $sql = "DELETE C FROM `$child_table` C";
+    $sql .= " LEFT JOIN `$parent_table` P USING (`$id_column`)";
+    $sql .= " WHERE P.`$id_column` IS NULL";
+
+    $result = dbQuery($sql, array());
+
+    recordDbStatistic('delete', $time_start);
+    if ($result) {
+        return mysqli_affected_rows($database_link);
+    } else {
+        return false;
+    }
+}
+
 /*
  * Fetches all of the rows (associatively) from the last performed query.
  * Most other retrieval functions build off this

includes/discovery/applications.inc.php

@@ -105,6 +105,9 @@
     }
 }
 
+// clean application_metrics
+dbDeleteOrphans('applications', 'application_metrics', 'app_id');
+
 echo PHP_EOL;
 
 unset(

includes/polling/applications/nginx.inc.php

@@ -11,7 +11,6 @@
     $nginx = snmp_get($device, '.1.3.6.1.4.1.8072.1.3.2.3.1.2.5.110.103.105.110.120', '-Ovq');
 }
 $nginx = trim($nginx, '"');
-update_application($app, $nginx);
 
 echo ' nginx';
 
@@ -36,6 +35,7 @@
 
 $tags = compact('name', 'app_id', 'rrd_name', 'rrd_def');
 data_update($device, 'app', $tags, $fields);
+update_application($app, $nginx, '', $fields);
 
 // Unset the variables we set here
 unset($nginx, $active, $reading, $writing, $waiting, $req, $rrd_name, $rrd_def, $tags);

includes/polling/functions.inc.php

@@ -574,9 +574,10 @@ function location_to_latlng($device)
  *
  * @param array $app app from the db, including app_id
  * @param string $response This should be the full output
- * @param string $current This is the current value we store in rrd for graphing
+ * @param string $status This is the current value for alerting
+ * @param array $metrics an array of additional metrics to store in the database for alerting
  */
-function update_application($app, $response, $current = '')
+function update_application($app, $response, $status = '', $metrics = array())
 {
     if (!is_numeric($app['app_id'])) {
         d_echo('$app does not contain app_id, could not update');
@@ -585,7 +586,7 @@ function update_application($app, $response, $current = '')
 
     $data = array(
         'app_state'  => 'UNKNOWN',
-        'app_status' => $current,
+        'app_status' => $status,
         'timestamp'  => array('NOW()'),
     );
 
@@ -603,6 +604,53 @@ function update_application($app, $response, $current = '')
         $data['app_state_prev'] = $app['app_state'];
     }
     dbUpdate($data, 'applications', '`app_id` = ?', array($app['app_id']));
+
+    // update metrics
+    if (!empty($metrics)) {
+        $db_metrics = dbFetchRows('SELECT * FROM `application_metrics` WHERE app_id=?', array($app['app_id']));
+        $db_metrics = array_by_column($db_metrics, 'metric');
+
+        echo ': ';
+        foreach ($metrics as $metric_name => $value) {
+            if (!isset($db_metrics[$metric_name])) {
+                // insert new metric
+                dbInsert(
+                    array(
+                        'app_id' => $app['app_id'],
+                        'metric' => $metric_name,
+                        'value' => $value,
+                    ),
+                    'application_metrics'
+                );
+                echo '+';
+            } elseif ($value != $db_metrics[$metric_name]['value']) {
+                dbUpdate(
+                    array(
+                        'value' => $value,
+                        'value_prev' => $db_metrics[$metric_name]['value'],
+                    ),
+                    'application_metrics',
+                    'app_id=? && metric=?',
+                    array($app['app_id'], $metric_name)
+                );
+                echo 'U';
+            } else {
+                echo '.';
+            }
+
+            unset($db_metrics[$metric_name]);
+        }
+
+        // remove no longer existing metrics (generally should not happen
+        foreach ($db_metrics as $db_metric) {
+            dbDelete(
+                'application_metrics',
+                'app_id=? && metric=?',
+                array($app['app_id'], $db_metric['metric'])
+            );
+            echo '-';
+        }
+    }
 }
 
 function convert_to_celsius($value)

misc/db_schema.yaml

@@ -133,6 +133,14 @@ applications:
   Indexes:
     PRIMARY: { Name: PRIMARY, Columns: [app_id], Unique: true, Type: BTREE }
     unique_index: { Name: unique_index, Columns: [device_id, app_type], Unique: true, Type: BTREE }
+application_metrics:
+  Columns:
+    - { Field: app_id, Type: int(11), 'Null': false, Extra: '' }
+    - { Field: metric, Type: varchar(18), 'Null': false, Extra: '' }
+    - { Field: value, Type: int(11), 'Null': true, Extra: '' }
+    - { Field: value_prev, Type: int(11), 'Null': true, Extra: '' }
+  Indexes:
+    application_metrics_app_id_metric_uindex: { Name: application_metrics_app_id_metric_uindex, Columns: [app_id, metric], Unique: true, Type: BTREE }
 authlog:
   Columns:
     - { Field: id, Type: int(11), 'Null': false, Extra: auto_increment }

sql-schema/219.sql

@@ -0,0 +1,2 @@
+CREATE TABLE application_metrics (app_id INT(11) NOT NULL, metric VARCHAR(18) NOT NULL, value INT(11), value_prev INT(11));
+CREATE UNIQUE INDEX application_metrics_app_id_metric_uindex ON application_metrics (app_id, metric);