Add max_allowed_packet diagnostic check (#13497)

* Add max_allowed_packet diagnostic check

* Update DbMaxPacket.php

3 files changed, 53 insertions, 0 deletions

diff --git a/plugins/Diagnostics/Diagnostic/DbMaxPacket.php b/plugins/Diagnostics/Diagnostic/DbMaxPacket.php
new file mode 100644
index 0000000000..91745db88d
--- /dev/null
+++ b/plugins/Diagnostics/Diagnostic/DbMaxPacket.php
@@ -0,0 +1,50 @@
+<?php
+
+namespace Piwik\Plugins\Diagnostics\Diagnostic;
+
+use Piwik\Db;
+use Piwik\MetricsFormatter;
+use Piwik\Piwik;
+use Piwik\SettingsPiwik;
+use Piwik\Translation\Translator;
+
+/**
+ * Check if Piwik is connected with database through ssl.
+ */
+class DbMaxPacket implements Diagnostic
+{
+    /**
+     * @var Translator
+     */
+    private $translator;
+
+    const MIN_VALUE_MAX_PACKET_MB = 64;
+
+    public function __construct(Translator $translator)
+    {
+        $this->translator = $translator;
+    }
+
+    public function execute()
+    {
+        if (!SettingsPiwik::isPiwikInstalled()) {
+            return array(); // only possible to perform check once we have DB connection
+        }
+
+        $maxPacketBytes = Db::fetchRow("SHOW VARIABLES LIKE 'max_allowed_packet'");
+
+        $status = DiagnosticResult::STATUS_OK;
+        $label = $this->translator->translate('Diagnostics_MysqlMaxPacketSize');
+        $comment = '';
+
+        $minSize = self::MIN_VALUE_MAX_PACKET_MB * 1000 * 1000; // not using 1024 just in case... this amount be good enough
+        if (!empty($maxPacketBytes['Value']) && $maxPacketBytes['Value'] < $minSize) {
+            $status = DiagnosticResult::STATUS_WARNING;
+            $pretty = MetricsFormatter::getPrettySizeFromBytes($maxPacketBytes['Value'], 'M');
+            $configured = str_replace(array(' M', '&nbsp;M'), 'MB', $pretty);
+            $comment = Piwik::translate('Diagnostics_MysqlMaxPacketSizeWarning', array('64MB', $configured));
+        }
+
+        return array(DiagnosticResult::singleResult($label, $status, $comment));
+    }
+}
diff --git a/plugins/Diagnostics/config/config.php b/plugins/Diagnostics/config/config.php
index 13bf140925..0a7c51bf72 100644
--- a/plugins/Diagnostics/config/config.php
+++ b/plugins/Diagnostics/config/config.php
@@ -25,6 +25,7 @@ return array(
         DI\get('Piwik\Plugins\Diagnostics\Diagnostic\CronArchivingCheck'),
         DI\get('Piwik\Plugins\Diagnostics\Diagnostic\LoadDataInfileCheck'),
         Di\get('Piwik\Plugins\Diagnostics\Diagnostic\DbOverSSLCheck'),
+        Di\get('Piwik\Plugins\Diagnostics\Diagnostic\DbMaxPacket'),
         Di\get('Piwik\Plugins\Diagnostics\Diagnostic\ForceSSLCheck'),
     ),
     // Allows other plugins to disable diagnostics that were previously registered
diff --git a/plugins/Diagnostics/lang/en.json b/plugins/Diagnostics/lang/en.json
index 2fed3e81a1..38c1990891 100644
--- a/plugins/Diagnostics/lang/en.json
+++ b/plugins/Diagnostics/lang/en.json
@@ -1,6 +1,8 @@
 {
     "Diagnostics": {
         "ConfigFileTitle": "Config file",
+        "MysqlMaxPacketSize": "Max Packet Size",
+        "MysqlMaxPacketSizeWarning": "It is recommended to configure a 'max_allowed_packet' size in your MySQL database of at least %s. Configured is currently %s.",
         "ConfigFileIntroduction": "Here you can view the Matomo configuration. If you are running Matomo in a load balanced environment the page might be different depending from which server this page is loaded. Rows with a different background color are changed config values that are specified for example in the %1$s file.",
         "HideUnchanged": "If you want to see only changed values you can %1$shide all unchanged values%2$s.",
         "Sections": "Sections"