Proyectos de Subversion Moodle

<?php

// This file is part of Moodle - http://moodle.org/

//

// Moodle is free software: you can redistribute it and/or modify

// it under the terms of the GNU General Public License as published by

// the Free Software Foundation, either version 3 of the License, or

// (at your option) any later version.

//

// Moodle is distributed in the hope that it will be useful,

// but WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

// GNU General Public License for more details.

//

// You should have received a copy of the GNU General Public License

// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.

/**

 * DML read/read-write database handle use tests

 *

 * @package    core

 * @category   dml

 * @copyright  2018 Srdjan Janković, Catalyst IT

 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

namespace core;

defined('MOODLE_INTERNAL') || die();

require_once(__DIR__.'/fixtures/read_replica_moodle_database_table_names.php');

require_once(__DIR__.'/fixtures/read_replica_moodle_database_special.php');

require_once(__DIR__.'/../../tests/fixtures/event_fixtures.php');

/**

 * DML read/read-write database handle use tests

 *

 * @package    core

 * @category   dml

 * @copyright  2018 Catalyst IT

 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 * @covers     \moodle_read_replica_trait

 */

final class dml_read_replica_test extends \database_driver_testcase {

    /** @var float */

    static private $dbreadonlylatency = 0.8;

    /**

     * Instantiates a test database interface object.

     *

     * @param bool $wantlatency

     * @param mixed $readonly

     * @param mixed $dbclass

     * @return read_replica_moodle_database $db

     */

    public function new_db(

        $wantlatency = false,

        $readonly = [

            ['dbhost' => 'test_ro1', 'dbport' => 1, 'dbuser' => 'test1', 'dbpass' => 'test1'],

            ['dbhost' => 'test_ro2', 'dbport' => 2, 'dbuser' => 'test2', 'dbpass' => 'test2'],

            ['dbhost' => 'test_ro3', 'dbport' => 3, 'dbuser' => 'test3', 'dbpass' => 'test3'],

        ],

        $dbclass = read_replica_moodle_database::class

    ): read_replica_moodle_database {

        $dbhost = 'test_rw';

        $dbname = 'test';

        $dbuser = 'test';

        $dbpass = 'test';

        $prefix = 'test_';

        $dboptions = ['readonly' => ['instance' => $readonly, 'exclude_tables' => ['exclude']]];

        if ($wantlatency) {

            $dboptions['readonly']['latency'] = self::$dbreadonlylatency;

        }

        $db = new $dbclass();

        $db->connect($dbhost, $dbuser, $dbpass, $dbname, $prefix, $dboptions);

        return $db;

    }

    /**

     * Asert that the mock handle returned from read_replica_moodle_database methods

     * is a readonly replica handle.

     *

     * @param string $handle

     * @return void

     */

    private function assert_readonly_handle($handle): void {

        $this->assertMatchesRegularExpression('/^test_ro\d:\d:test\d:test\d$/', $handle);

    }

    /**

     * moodle_read_replica_trait::table_names() test data provider

     *

     * @return array

     * @dataProvider table_names_provider

     */

    public static function table_names_provider(): array {

        return [

            [

                "SELECT *

                 FROM {user} u

                 JOIN (

                     SELECT DISTINCT u.id FROM {user} u

                     JOIN {user_enrolments} ue1 ON ue1.userid = u.id

                     JOIN {enrol} e ON e.id = ue1.enrolid

                     WHERE u.id NOT IN (

                         SELECT DISTINCT ue.userid FROM {user_enrolments} ue

                         JOIN {enrol} e ON (e.id = ue.enrolid AND e.courseid = 1)

                         WHERE ue.status = 'active'

                           AND e.status = 'enabled'

                           AND ue.timestart < now()

                           AND (ue.timeend = 0 OR ue.timeend > now())

                     )

                 ) je ON je.id = u.id

                 JOIN (

                     SELECT DISTINCT ra.userid

                       FROM {role_assignments} ra

                      WHERE ra.roleid IN (1, 2, 3)

                        AND ra.contextid = 'ctx'

                  ) rainner ON rainner.userid = u.id

                  WHERE u.deleted = 0",

                [

                    'user',

                    'user',

                    'user_enrolments',

                    'enrol',

                    'user_enrolments',

                    'enrol',

                    'role_assignments',

                ]

            ],

        ];

    }

    /**

     * Test moodle_read_replica_trait::table_names() query parser.

     *

     * @param string $sql

     * @param array $tables

     * @return void

     * @dataProvider table_names_provider

     */

    public function test_table_names($sql, $tables): void {

        $db = new read_replica_moodle_database_table_names();

        $this->assertEquals($tables, $db->table_names($db->fix_sql_params($sql)[0]));

    }

    /**

     * Test correct database handles are used in a read-read-write-read scenario.

     * Test lazy creation of the write handle.

     *

     * @return void

     */

    public function test_read_read_write_read(): void {

        $DB = $this->new_db(true);

        $this->assertEquals(0, $DB->perf_get_reads_replica());

        $this->assertNull($DB->get_dbhwrite());

        $handle = $DB->get_records('table');

        $this->assert_readonly_handle($handle);

        $readsreplica = $DB->perf_get_reads_replica();

        $this->assertGreaterThan(0, $readsreplica);

        $this->assertNull($DB->get_dbhwrite());

        $handle = $DB->get_records('table2');

        $this->assert_readonly_handle($handle);

        $readsreplica = $DB->perf_get_reads_replica();

        $this->assertGreaterThan(1, $readsreplica);

        $this->assertNull($DB->get_dbhwrite());

        $now = microtime(true);

        $handle = $DB->insert_record_raw('table', array('name' => 'blah'));

        $this->assertEquals('test_rw::test:test', $handle);

        if (microtime(true) - $now < self::$dbreadonlylatency) {

            $handle = $DB->get_records('table');

            $this->assertEquals('test_rw::test:test', $handle);

            $this->assertEquals($readsreplica, $DB->perf_get_reads_replica());

            sleep(1);

        }

        $handle = $DB->get_records('table');

        $this->assert_readonly_handle($handle);

        $this->assertEquals($readsreplica + 1, $DB->perf_get_reads_replica());

    }

    /**

     * Test correct database handles are used in a read-write-write scenario.

     *

     * @return void

     */

    public function test_read_write_write(): void {

        $DB = $this->new_db();

        $this->assertEquals(0, $DB->perf_get_reads_replica());

        $this->assertNull($DB->get_dbhwrite());

        $handle = $DB->get_records('table');

        $this->assert_readonly_handle($handle);

        $readsreplica = $DB->perf_get_reads_replica();

        $this->assertGreaterThan(0, $readsreplica);

        $this->assertNull($DB->get_dbhwrite());

        $handle = $DB->insert_record_raw('table', array('name' => 'blah'));

        $this->assertEquals('test_rw::test:test', $handle);

        $handle = $DB->update_record_raw('table', array('id' => 1, 'name' => 'blah2'));

        $this->assertEquals('test_rw::test:test', $handle);

        $this->assertEquals($readsreplica, $DB->perf_get_reads_replica());

    }

    /**

     * Test correct database handles are used in a write-read-read scenario.

     *

     * @return void

     */

    public function test_write_read_read(): void {

        $DB = $this->new_db();

        $this->assertEquals(0, $DB->perf_get_reads_replica());

        $this->assertNull($DB->get_dbhwrite());

        $handle = $DB->insert_record_raw('table', array('name' => 'blah'));

        $this->assertEquals('test_rw::test:test', $handle);

        $this->assertEquals(0, $DB->perf_get_reads_replica());

        $handle = $DB->get_records('table');

        $this->assertEquals('test_rw::test:test', $handle);

        $this->assertEquals(0, $DB->perf_get_reads_replica());

        $handle = $DB->get_records_sql("SELECT * FROM {table2} JOIN {table}");

        $this->assertEquals('test_rw::test:test', $handle);

        $this->assertEquals(0, $DB->perf_get_reads_replica());

        sleep(1);

        $handle = $DB->get_records('table');

        $this->assert_readonly_handle($handle);

        $this->assertEquals(1, $DB->perf_get_reads_replica());

        $handle = $DB->get_records('table2');

        $this->assert_readonly_handle($handle);

        $this->assertEquals(2, $DB->perf_get_reads_replica());

        $handle = $DB->get_records_sql("SELECT * FROM {table2} JOIN {table}");

        $this->assert_readonly_handle($handle);

        $this->assertEquals(3, $DB->perf_get_reads_replica());

    }

    /**

     * Test readonly handle is not used for reading from temptables.

     *

     * @return void

     */

    public function test_read_temptable(): void {

        $DB = $this->new_db();

        $DB->add_temptable('temptable1');

        $this->assertEquals(0, $DB->perf_get_reads_replica());

        $this->assertNull($DB->get_dbhwrite());

        $handle = $DB->get_records('temptable1');

        $this->assertEquals('test_rw::test:test', $handle);

        $this->assertEquals(0, $DB->perf_get_reads_replica());

        $DB->delete_temptable('temptable1');

    }

    /**

     * Test readonly handle is not used for reading from excluded tables.

     *

     * @return void

     */

    public function test_read_excluded_tables(): void {

        $DB = $this->new_db();

        $this->assertEquals(0, $DB->perf_get_reads_replica());

        $this->assertNull($DB->get_dbhwrite());

        $handle = $DB->get_records('exclude');

        $this->assertEquals('test_rw::test:test', $handle);

        $this->assertEquals(0, $DB->perf_get_reads_replica());

    }

    /**

     * Test readonly handle is not used during transactions.

     * Test last written time is adjusted post-transaction,

     * so the latency parameter is applied properly.

     *

     * @return void

     */

    public function test_transaction(): void {

        $DB = $this->new_db(true);

        $this->assertNull($DB->get_dbhwrite());

        $skip = false;

        $transaction = $DB->start_delegated_transaction();

        $now = microtime(true);

        $handle = $DB->get_records_sql("SELECT * FROM {table}");

        // Use rw handle during transaction.

        $this->assertEquals('test_rw::test:test', $handle);

        $handle = $DB->insert_record_raw('table', array('name' => 'blah'));

        // Introduce delay so we can check that table write timestamps

        // are adjusted properly.

        sleep(1);

        $transaction->allow_commit();

        // This condition should always evaluate true, however we need to

        // safeguard from an unaccounted delay that can break this test.

        if (microtime(true) - $now < 1 + self::$dbreadonlylatency) {

            // Not enough time passed, use rw handle.

            $handle = $DB->get_records_sql("SELECT * FROM {table}");

            $this->assertEquals('test_rw::test:test', $handle);

            // Make sure enough time passes.

            sleep(1);

        } else {

            $skip = true;

        }

        // Exceeded latency time, use ro handle.

        $handle = $DB->get_records_sql("SELECT * FROM {table}");

        $this->assert_readonly_handle($handle);

        if ($skip) {

            $this->markTestSkipped("Delay too long to test write handle immediately after transaction");

        }

    }

    /**

     * Test readonly handle is not used immediately after update

     * Test last written time is adjusted post-write,

     * so the latency parameter is applied properly.

     *

     * @return void

     */

    public function test_long_update(): void {

        $DB = $this->new_db(true);

        $this->assertNull($DB->get_dbhwrite());

        $skip = false;

        list($sql, $params, $ptype) = $DB->fix_sql_params("UPDATE {table} SET a = 1 WHERE id = 1");

        $DB->with_query_start_end($sql, $params, SQL_QUERY_UPDATE, function ($dbh) use (&$now) {

            sleep(1);

            $now = microtime(true);

        });

        // This condition should always evaluate true, however we need to

        // safeguard from an unaccounted delay that can break this test.

        if (microtime(true) - $now < self::$dbreadonlylatency) {

            // Not enough time passed, use rw handle.

            $handle = $DB->get_records_sql("SELECT * FROM {table}");

            $this->assertEquals('test_rw::test:test', $handle);

            // Make sure enough time passes.

            sleep(1);

        } else {

            $skip = true;

        }

        // Exceeded latency time, use ro handle.

        $handle = $DB->get_records_sql("SELECT * FROM {table}");

        $this->assert_readonly_handle($handle);

        if ($skip) {

            $this->markTestSkipped("Delay too long to test write handle immediately after transaction");

        }

    }

    /**

     * Test readonly handle is not used with events

     * when the latency parameter is applied properly.

     *

     * @return void

     */

    public function test_transaction_with_events(): void {

        $this->with_global_db(function () {

            global $DB;

            $DB = $this->new_db(true, ['test_ro'], read_replica_moodle_database_special::class);

            $DB->set_tables([

                'config_plugins' => [

                    'columns' => [

                        'plugin' => (object)['meta_type' => ''],

                    ]

                ]

            ]);

            $this->assertNull($DB->get_dbhwrite());

            $called = false;

            $transaction = $DB->start_delegated_transaction();

            $now = microtime(true);

            $observers = [

                [

                    'eventname'   => '\core_tests\event\unittest_executed',

                    'callback'    => function (\core_tests\event\unittest_executed $event) use ($DB, $now, &$called) {

                        $called = true;

                        $this->assertFalse($DB->is_transaction_started());

                        // This condition should always evaluate true, however we need to

                        // safeguard from an unaccounted delay that can break this test.

                        if (microtime(true) - $now < 1 + self::$dbreadonlylatency) {

                            // Not enough time passed, use rw handle.

                            $handle = $DB->get_records_sql_p("SELECT * FROM {table}");

                            $this->assertEquals('test_rw::test:test', $handle);

                            // Make sure enough time passes.

                            sleep(1);

                        } else {

                            $this->markTestSkipped("Delay too long to test write handle immediately after transaction");

                        }

                        // Exceeded latency time, use ro handle.

                        $handle = $DB->get_records_sql_p("SELECT * FROM {table}");

                        $this->assertEquals('test_ro::test:test', $handle);

                    },

                    'internal'    => 0,

                ],

            ];

            \core\event\manager::phpunit_replace_observers($observers);

            $handle = $DB->get_records_sql_p("SELECT * FROM {table}");

            // Use rw handle during transaction.

            $this->assertEquals('test_rw::test:test', $handle);

            $handle = $DB->insert_record_raw('table', array('name' => 'blah'));

            // Introduce delay so we can check that table write timestamps

            // are adjusted properly.

            sleep(1);

            $event = \core_tests\event\unittest_executed::create([

                'context' => \context_system::instance(),

                'other' => ['sample' => 1]

            ]);

            $event->trigger();

            $transaction->allow_commit();

            $this->assertTrue($called);

        });

    }

    /**

     * Test failed readonly connection falls back to write connection.

     *

     * @return void

     */

    public function test_read_only_conn_fail(): void {

        $this->resetDebugging();

        $DB = $this->new_db(false, 'test_ro_fail');

        $this->assertEquals(0, $DB->perf_get_reads_replica());

        $this->assertNotNull($DB->get_dbhwrite());

        $handle = $DB->get_records('table');

        $this->assertEquals('test_rw::test:test', $handle);

        $readsreplica = $DB->perf_get_reads_replica();

        $this->assertEquals(0, $readsreplica);

        $debugging = array_map(function ($d) {

            return $d->message;

        }, $this->getDebuggingMessages());

        $this->resetDebugging();

        $this->assertEquals([

            'Readonly db connection failed for host test_ro_fail: test_ro_fail',

            'Readwrite db connection succeeded for host test_rw',

        ], $debugging);

    }

    /**

     * In multiple replicas scenario, test failed readonly connection falls back to

     * another readonly connection.

     *

     * @return void

     */

    public function test_read_only_conn_first_fail(): void {

        $this->resetDebugging();

        $DB = $this->new_db(false, ['test_ro_fail', 'test_ro_ok']);

        $this->assertEquals(0, $DB->perf_get_reads_replica());

        $this->assertNull($DB->get_dbhwrite());

        $handle = $DB->get_records('table');

        $this->assertEquals('test_ro_ok::test:test', $handle);

        $readsreplica = $DB->perf_get_reads_replica();

        $this->assertEquals(1, $readsreplica);

        $debugging = array_map(function ($d) {

            return $d->message;

        }, $this->getDebuggingMessages());

        $this->resetDebugging();

        $this->assertEquals([

            'Readonly db connection failed for host test_ro_fail: test_ro_fail',

            'Readonly db connection succeeded for host test_ro_ok',

        ], $debugging);

    }

    /**

     * Helper to restore global $DB

     *

     * @param callable $test

     * @return void

     */

    private function with_global_db($test) {

        global $DB;

        $dbsave = $DB;

        try {

            $test();

        }

        finally {

            $DB = $dbsave;

        }

    }

    /**

     * Test lock_db table exclusion

     *

     * @return void

     */

    public function test_lock_db(): void {

        $this->with_global_db(function () {

            global $DB;

            $DB = $this->new_db(true, ['test_ro'], read_replica_moodle_database_special::class);

            $DB->set_tables([

                'lock_db' => [

                    'columns' => [

                        'resourcekey' => (object)['meta_type' => ''],

                        'owner' => (object)['meta_type' => ''],

                    ]

                ]

            ]);

            $this->assertEquals(0, $DB->perf_get_reads_replica());

            $this->assertNull($DB->get_dbhwrite());

            $lockfactory = new \core\lock\db_record_lock_factory('default');

            if (!$lockfactory->is_available()) {

                $this->markTestSkipped("db_record_lock_factory not available");

            }

            $lock = $lockfactory->get_lock('abc', 2);

            $lock->release();

            $this->assertEquals(0, $DB->perf_get_reads_replica());

            $this->assertTrue($DB->perf_get_reads() > 0);

        });

    }

    /**

     * Test sessions table exclusion

     *

     * @return void

     */

    public function test_sessions(): void {

        $this->with_global_db(function () {

            global $DB, $CFG;

            $CFG->dbsessions = true;

            $DB = $this->new_db(true, ['test_ro'], read_replica_moodle_database_special::class);

            $DB->set_tables([

                'sessions' => [

                    'columns' => [

                        'sid' => (object)['meta_type' => ''],

                    ]

                ]

            ]);

            $this->assertEquals(0, $DB->perf_get_reads_replica());

            $this->assertNull($DB->get_dbhwrite());

            $session = new \core\session\database();

            $session->read('dummy');

            $this->assertEquals(0, $DB->perf_get_reads_replica());

            $this->assertTrue($DB->perf_get_reads() > 0);

        });

        \core\session\manager::restart_with_write_lock(false);

    }

}