Issue 8550: Check for a good table_definition cache value

diff --git a/src/Database/DBA.php b/src/Database/DBA.php
index 9c3c3a52e5c4890ed7926c0683a0da4a195d016b..9825d06c683a7791fee2a9ff95e9d7ff43f0b3e2 100644 (file)
--- a/src/Database/DBA.php
+++ b/src/Database/DBA.php
@@ -741,6 +741,17 @@ class DBA
                return DI::dba()->processlist();
        }
 
+       /**
+        * Fetch a database variable
+        *
+        * @param string $name
+        * @return string content
+        */
+       public static function getVariable(string $name)
+       {
+               return DI::dba()->getVariable($name);
+       }
+
        /**
         * Checks if $array is a filled array with at least one entry.
         *

diff --git a/src/Database/Database.php b/src/Database/Database.php
index db906bd01e05e40675e049c6adc45802f333798b..9892fc19afeb97593df9e558868e3d450333fb2e 100644 (file)
--- a/src/Database/Database.php
+++ b/src/Database/Database.php
@@ -1645,6 +1645,21 @@ class Database
                return (["list" => $statelist, "amount" => $processes]);
        }
 
+       /**
+        * Fetch a database variable
+        *
+        * @param string $name
+        * @return string content
+        */
+       public function getVariable(string $name)
+       {
+               $result = $this->fetchFirst("SHOW GLOBAL VARIABLES WHERE `Variable_name` = ?", $name);
+               if (!isset($result['Value'])) {
+                       return null;
+               }
+               return $result['Value'];
+       }
+
        /**
         * Checks if $array is a filled array with at least one entry.
         *

diff --git a/src/Module/Admin/Summary.php b/src/Module/Admin/Summary.php
index f676792d82d986751f999654c6738722e84a8edd..7bd7901f7805d0fdd09fb323971b270596c4e713 100644 (file)
--- a/src/Module/Admin/Summary.php
+++ b/src/Module/Admin/Summary.php
@@ -55,6 +55,16 @@ class Summary extends BaseAdmin
                        $warningtext[] = DI::l10n()->t('Your DB still runs with InnoDB tables in the Antelope file format. You should change the file format to Barracuda. Friendica is using features that are not provided by the Antelope format. See <a href="%s">here</a> for a guide that may be helpful converting the table engines. You may also use the command <tt>php bin/console.php dbstructure toinnodb</tt> of your Friendica installation for an automatic conversion.<br />', 'https://dev.mysql.com/doc/refman/5.7/en/innodb-file-format.html');
                }
 
+               // Avoid the database error 1615 "Prepared statement needs to be re-prepared", see https://github.com/friendica/friendica/issues/8550
+               $table_definition_cache = DBA::getVariable('table_definition_cache');
+               $table_open_cache = DBA::getVariable('table_open_cache');
+               if (!empty($table_definition_cache) && !empty($table_open_cache)) {
+                       $suggested_definition_cache = max(400, round($table_open_cache / 2, 1));
+                       if ($suggested_definition_cache > $table_definition_cache) {
+                               $warningtext[] = DI::l10n()->t('Your table_definition_cache is too low (%d). This can lead to the database error "Prepared statement needs to be re-prepared". Please set it at least to %d (or -1 for autosizing). See <a href="%s">here</a> for more information.<br />', $table_definition_cache, $suggested_definition_cache, 'https://dev.mysql.com/doc/refman/5.7/en/server-system-variables.html#sysvar_table_definition_cache');
+                       }
+               }
+
                // Check if github.com/friendica/master/VERSION is higher then
                // the local version of Friendica. Check is opt-in, source may be master or devel branch
                if (DI::config()->get('system', 'check_new_version_url', 'none') != 'none') {