diff --git a/daily.php b/daily.php
index 2929c99ebe..7de5822dd6 100644
--- a/daily.php
+++ b/daily.php
@@ -204,39 +204,65 @@ if ($options['f'] === 'notifications') {
 }
 
 if ($options['f'] === 'bill_data') {
-    try {
-        if (Config::get('distributed_poller')) {
-            MemcacheLock::lock('syslog_purge', 0, 86000);
-        }
-        $billing_data_purge = Config::get('billing_data_purge');
-        if (is_numeric($billing_data_purge) && $billing_data_purge > 0) {
-            # Deletes data older than XX months before the start of the last complete billing period
-            echo "Deleting billing data more than $billing_data_purge month before the last completed billing cycle\n";
-            $sql = "DELETE bill_data
-                    FROM bill_data
-                        INNER JOIN (SELECT bill_id, 
-                            SUBDATE(
-                                SUBDATE(
-                                    ADDDATE(
-                                        subdate(curdate(), (day(curdate())-1)),             # Start of this month
-                                        bill_day - 1),                                      # Billing anniversary
-                                    INTERVAL IF(bill_day > DAY(curdate()), 1, 0) MONTH),    # Deal with anniversary not yet happened this month
-                                INTERVAL ? MONTH) AS threshold                              # Adjust based on config threshold
-                    FROM bills) q
-                    ON bill_data.bill_id = q.bill_id AND bill_data.timestamp < q.threshold;";
-            dbQuery($sql, array($billing_data_purge));
-        }
-    } catch (LockException $e) {
-        echo $e->getMessage() . PHP_EOL;
-        exit(-1);
-    }
+    # Deletes data older than XX months before the start of the last complete billing period
+    $msg = "Deleting billing data more than %d month before the last completed billing cycle\n";
+    $table = 'bill_data';
+    $sql = "DELETE bill_data
+            FROM bill_data
+                INNER JOIN (SELECT bill_id, 
+                    SUBDATE(
+                        SUBDATE(
+                            ADDDATE(
+                                subdate(curdate(), (day(curdate())-1)),             # Start of this month
+                                bill_day - 1),                                      # Billing anniversary
+                            INTERVAL IF(bill_day > DAY(curdate()), 1, 0) MONTH),    # Deal with anniversary not yet happened this month
+                        INTERVAL ? MONTH) AS threshold                              # Adjust based on config threshold
+            FROM bills) q
+            ON bill_data.bill_id = q.bill_id AND bill_data.timestamp < q.threshold;";
+    lock_and_purge_query($table, $sql, $msg);
 }
 
 if ($options['f'] === 'alert_log') {
-    $ret = lock_and_purge('alert_log', 'time_logged < DATE_SUB(NOW(),INTERVAL ? DAY)');
-    exit($ret);
+    $msg = "Deleting alert_logs more than %d days that are not active\n";
+    $table = 'alert_log';
+    $sql = "DELETE alert_log
+                FROM alert_log
+                INNER JOIN alerts
+                ON alerts.device_id=alert_log.device_id AND alerts.rule_id=alert_log.rule_id
+                WHERE alerts.state=0 AND alert_log.time_logged < DATE_SUB(NOW(),INTERVAL ? DAY)
+                ";
+    lock_and_purge_query($table, $sql, $msg);
+    
+    # alert_log older than $config['alert_log_purge'] days match now only the alert_log of active alerts
+    # in case of flapping of an alert, many entries are kept in alert_log
+    # we want only to keep the last alert_log that contains the alert details
+
+    $msg = "Deleting history of active alert_logs more than %d days\n";
+    $sql = "DELETE
+                    FROM alert_log
+                    WHERE id IN(
+                        SELECT id FROM(
+                            SELECT id
+                            FROM alert_log a1
+                            WHERE
+                                time_logged < DATE_SUB(NOW(),INTERVAL ? DAY)
+                                AND (device_id, rule_id, time_logged) NOT IN (
+                                    SELECT device_id, rule_id, max(time_logged)
+                                    FROM alert_log a2 WHERE a1.device_id = a2.device_id AND a1.rule_id = a2.rule_id
+                                    AND a2.time_logged < DATE_SUB(NOW(),INTERVAL ? DAY)
+                                )
+                        ) as c
+                    )
+                ";
+    $purge_duration = Config::get('alert_log_purge');
+    if (!(is_numeric($purge_duration) && $purge_duration > 0)) {
+        return -2;
+    }
+    $sql = str_replace("?", strval($purge_duration), $sql);
+    lock_and_purge_query($table, $sql, $msg);
 }
 
+
 if ($options['f'] === 'purgeusers') {
     try {
         if (Config::get('distributed_poller')) {
diff --git a/includes/functions.php b/includes/functions.php
index 428f82f430..57cfc45b80 100644
--- a/includes/functions.php
+++ b/includes/functions.php
@@ -2526,6 +2526,36 @@ function lock_and_purge($table, $sql)
     }
 }
 
+/**
+ * If Distributed, create a lock, then purge the mysql table according to the sql query
+ *
+ * @param string $table
+ * @param string $sql
+ * @param string $msg
+ * @return int exit code
+ */
+function lock_and_purge_query($table, $sql, $msg)
+{
+    $purge_name = $table . '_purge';
+
+    if (Config::get('distributed_poller')) {
+        MemcacheLock::lock($purge_name, 0, 86000);
+    }
+    $purge_duration = Config::get($purge_name);
+    if (!(is_numeric($purge_duration) && $purge_duration > 0)) {
+        return -2;
+    }
+    try {
+        if (dbQuery($sql, array($purge_duration))) {
+            printf($msg, $purge_duration);
+        }
+    } catch (LockException $e) {
+        echo $e->getMessage() . PHP_EOL;
+        return -1;
+    }
+    return 0;
+}
+
 /**
  * Convert space separated hex OID content to character
  *