fix: mariadb client perceived as failed

Author: Gaetano Giunta

TODO.md

@@ -1,7 +1,6 @@
 - fix auth problems with mysql 8.0
 
 - worker: improve sql execution cmd:
-  + fix: why does mariadb cli command does return  -1 as exit code ?
   + allow it to take sql snippet from file
   + allow it to pick a set of desired servers
   + at end show results + time & mem taken for each db
@@ -41,6 +40,9 @@
 
 - postgresql: move stats_temp_directory to /tmpfs
 
+- worker: allow to run tests which consist of executing sql/sh/php payloads in parallel with N threads against each server.
+  This would allow to find out if any code construct has _scalability_ problems on a given db version
+
 - worker: add phpbench as dependency
 
 - allow to easily set up either prod/public or dev/private stacks via a parameter in .env

WHATSNEW.md

@@ -0,0 +1,19 @@
+Version 0.2 (unreleased)
+------------------------
+
+- Fixed: sql commands executed against mariadb would be reported as failed 
+
+
+Version 0.1
+-----------
+
+A preview release more than anything else.
+
+What works:
+
+- all current versions of MariaDB, MySQL and PostgreSQL are installed and available (MySQL 8.0 has a config problem with login auth though)
+- a cli script is available that runs a SQL snippet against all databases
+
+What does not work:
+
+- everything else

app/src/Command/SqlExecute.php

@@ -5,7 +5,7 @@
 use Symfony\Component\Console\Input\InputInterface;
 use Symfony\Component\Console\Output\OutputInterface;
 use Symfony\Component\Console\Input\InputOption;
-use Symfony\Component\Process\Process;
+use Db3v4l\Util\Process;
 use Symfony\Component\Yaml\Yaml;
 use Db3v4l\Service\DatabaseConfigurationManager;
 use Db3v4l\Service\SqlExecutorFactory;
@@ -41,6 +41,7 @@ protected function configure()
             //->addOption('output-type', null, InputOption::VALUE_REQUIRED, 'The format for the output: text, json or yml', 'text')
             ->addOption('timeout', null, InputOption::VALUE_REQUIRED, 'The maximum time to wait for execution (secs)', 600)
             ->addOption('max-parallel', null, InputOption::VALUE_REQUIRED, 'The maximum number of processes to run in parallel', 16)
+            ->addOption('dont-force-enabled-sigchild', null, InputOption::VALUE_NONE, "When using a separate php process to run each sql command, do not force Symfony to believe that php was compiled with --enable-sigchild option")
         ;
     }
 
@@ -54,28 +55,45 @@ protected function execute(InputInterface $input, OutputInterface $output)
     {
         $start = microtime(true);
 
+        // as per https://www.php.net/manual/en/function.ignore-user-abort.php: for cli scripts, it is probably a good idea
+        // to use ignore_user_abort
+        ignore_user_abort(true);
+
         $this->setOutput($output);
         $this->setVerbosity($output->getVerbosity());
 
         $dbList = $this->dbManager->listDatabases();
         $sql = $input->getOption('sql');
         $timeout = $input->getOption('timeout');
         $maxParallel = $input->getOption('max-parallel');
+        $dontForceSigchildEnabled = $input->getOption('dont-force-enabled-sigchild');
 
         if ($sql === '') {
             throw new \Exception("Please provide an sql command/snippted to be executed");
         }
 
+        // On Debian, which we use by default, SF has troubles understanding that php was compiled with --enable-sigchild
+        // We thus force it, but give end users an option to disable this
+        // For more details, see comment 12 at https://bugs.launchpad.net/ubuntu/+source/php5/+bug/516061
+        if (!$dontForceSigchildEnabled) {
+
+            Process::forceSigchildEnabled(true);
+        }
+
         /** @var Process[] $processes */
         $processes = [];
         foreach ($dbList as $dbName) {
             $dbConnectionSpec = $this->dbManager->getDatabaseConnectionSpecification($dbName);
-            $processes[$dbName] = $this->executorFactory->createForkedExecutor($dbConnectionSpec)->getProcess($sql);
+            $process = $this->executorFactory->createForkedExecutor($dbConnectionSpec)->getProcess($sql);
+
+            $process->setTimeout($timeout);
+
+            $processes[$dbName] = $process;
         }
 
         $this->writeln("Starting parallel execution...");
 
-        $this->processManager->runParallel($processes, $maxParallel, $timeout, 100, array($this, 'onSubProcessOutput'));
+        $this->processManager->runParallel($processes, $maxParallel, 100, array($this, 'onSubProcessOutput'));
 
         $failed = 0;
         $succeeded = 0;

app/src/Service/ProcessManager.php

@@ -13,11 +13,10 @@ class ProcessManager
     /**
      * @param Process[] $processes
      * @param int $maxParallel
-     * @param int $timeout secs
      * @param int $poll microseconds
      * @param Callable $callback takes 4 args: $type, $buffer, $processIndex, $process
      */
-    public function runParallel(array $processes, $maxParallel, $timeout = 86400, $poll = 1000, $callback = null)
+    public function runParallel(array $processes, $maxParallel, $poll = 1000, $callback = null)
     {
         $this->validateProcesses($processes);
         // do not modify the object pointers in the argument, copy to local working variable
@@ -29,7 +28,6 @@ public function runParallel(array $processes, $maxParallel, $timeout = 86400, $p
         $currentProcesses = array_splice($processesQueue, 0, $maxParallel);
         // start the initial stack of processes
         foreach ($currentProcesses as $idx => $process) {
-            $process->setTimeout($timeout);
             $process->start(function ($type, $buffer) use ($callback, $idx, $process) {
                 if ($callback) {
                     $callback($type, $buffer, $idx, $process);
@@ -73,4 +71,4 @@ protected function validateProcesses(array $processes)
             }
         }
     }
-}
+}

app/src/Service/SqlExecutor/Forked/Doctrine.php

@@ -2,8 +2,8 @@
 
 namespace Db3v4l\Service\SqlExecutor\Forked;
 
-use Symfony\Component\Process\Process;
 use Db3v4l\API\Interfaces\ForkedSqlExecutor;
+use Db3v4l\Util\Process;
 
 class Doctrine extends ForkedExecutor implements ForkedSqlExecutor
 {
@@ -15,4 +15,4 @@ public function getProcess($sql)
     {
         throw new \RuntimeException('TO BE IMPLEMENTED');
     }
-}
+}

app/src/Service/SqlExecutor/Forked/NativeClient.php

@@ -2,9 +2,8 @@
 
 namespace Db3v4l\Service\SqlExecutor\Forked;
 
-use Symfony\Component\Process\Process;
-
 use Db3v4l\API\Interfaces\ForkedSqlExecutor;
+use Db3v4l\Util\Process;
 
 class NativeClient extends ForkedExecutor implements ForkedSqlExecutor
 {

app/src/Util/Process.php

@@ -0,0 +1,24 @@
+<?php
+
+namespace Db3v4l\Util;
+
+use Symfony\Component\Process\Process as BaseProcess;
+
+class Process extends BaseProcess
+{
+    static $forceSigchildEnabled = null;
+
+    public static function forceSigchildEnabled($force)
+    {
+        self::$forceSigchildEnabled = (bool) $force;
+    }
+
+    protected function isSigchildEnabled()
+    {
+        if (null !== self::$forceSigchildEnabled) {
+            return self::$forceSigchildEnabled;
+        }
+
+        return parent::isSigchildEnabled();
+    }
+}