wiki.techinc.nl/tests/phpunit/includes/Storage/NameTableStoreTest.php
Aaron Schulz b707afa7f4 objectcache: optimize WAN cache key updates during HOLDOFF_TTL
Avoid the ADD operation spam from all threads trying to access
a tombstoned key by checking the interim value cache timestamp.
This also avoids the GET/CAS spam from threads that manage to
get the mutex. If a single thread repeatedly accesses the same
tombstoned value in rapid succession, there will significantly
less cache operation spam.

Do the same for cache updates to keys in the holdoff state
due to "check keys" or the "touchedCallback" function.

Relatedly, fix getWithSetCallback() to disregard interim values
set prior to or at the same time as the latest delete() call.
This can slightly reduce the chance of the cache being behind
replica DBs for a second. It also avoids unit test failures
were a series of deletes and cache access happen at the same
timestamp (via time injection or regular system time calls).

In addition:
* Add PASS_BY_REF flag with backwards compatibility to avoid
  bloating the signature of get()/getMulti() with the new
  tombstone information needed for the above changes.
* Avoid confusing pass-by-reference in getInterimValue() and
  fix use of incorrect $asOf parameter.
* Move some more logic into setInterimValue().
* Update some comments regarding broadcasted operations that
  were not true for the currently assumed mcrouter setup.
* Rename $cValue => $curValue and $versioned => $needsVersion
  for better readability.

Bug: T203786
Change-Id: I0eb3f9b697193d39a70dd3c0967311ad7e194f20
2019-03-04 10:00:29 +00:00

341 lines
11 KiB
PHP

<?php
namespace MediaWiki\Tests\Storage;
use BagOStuff;
use EmptyBagOStuff;
use HashBagOStuff;
use MediaWiki\Storage\NameTableAccessException;
use MediaWiki\Storage\NameTableStore;
use MediaWikiTestCase;
use Psr\Log\NullLogger;
use WANObjectCache;
use Wikimedia\Rdbms\Database;
use Wikimedia\Rdbms\LoadBalancer;
use Wikimedia\TestingAccessWrapper;
/**
* @author Addshore
* @group Database
* @covers \MediaWiki\Storage\NameTableStore
*/
class NameTableStoreTest extends MediaWikiTestCase {
public function setUp() {
$this->tablesUsed[] = 'slot_roles';
parent::setUp();
}
protected function addCoreDBData() {
// The default implementation causes the slot_roles to already have content. Skip that.
}
private function populateTable( $values ) {
$insertValues = [];
foreach ( $values as $name ) {
$insertValues[] = [ 'role_name' => $name ];
}
$this->db->insert( 'slot_roles', $insertValues );
}
private function getHashWANObjectCache( $cacheBag ) {
return new WANObjectCache( [ 'cache' => $cacheBag ] );
}
/**
* @param $db
* @return \PHPUnit_Framework_MockObject_MockObject|LoadBalancer
*/
private function getMockLoadBalancer( $db ) {
$mock = $this->getMockBuilder( LoadBalancer::class )
->disableOriginalConstructor()
->getMock();
$mock->expects( $this->any() )
->method( 'getConnection' )
->willReturn( $db );
return $mock;
}
private function getCallCheckingDb( $insertCalls, $selectCalls ) {
$mock = $this->getMockBuilder( Database::class )
->disableOriginalConstructor()
->getMock();
$mock->expects( $this->exactly( $insertCalls ) )
->method( 'insert' )
->willReturnCallback( function () {
return call_user_func_array( [ $this->db, 'insert' ], func_get_args() );
} );
$mock->expects( $this->exactly( $selectCalls ) )
->method( 'select' )
->willReturnCallback( function () {
return call_user_func_array( [ $this->db, 'select' ], func_get_args() );
} );
$mock->expects( $this->exactly( $insertCalls ) )
->method( 'affectedRows' )
->willReturnCallback( function () {
return call_user_func_array( [ $this->db, 'affectedRows' ], func_get_args() );
} );
$mock->expects( $this->any() )
->method( 'insertId' )
->willReturnCallback( function () {
return call_user_func_array( [ $this->db, 'insertId' ], func_get_args() );
} );
return $mock;
}
private function getNameTableSqlStore(
BagOStuff $cacheBag,
$insertCalls,
$selectCalls,
$normalizationCallback = null,
$insertCallback = null
) {
return new NameTableStore(
$this->getMockLoadBalancer( $this->getCallCheckingDb( $insertCalls, $selectCalls ) ),
$this->getHashWANObjectCache( $cacheBag ),
new NullLogger(),
'slot_roles', 'role_id', 'role_name',
$normalizationCallback,
false,
$insertCallback
);
}
public function provideGetAndAcquireId() {
return [
'no wancache, empty table' =>
[ new EmptyBagOStuff(), true, 1, [], 'foo', 1 ],
'no wancache, one matching value' =>
[ new EmptyBagOStuff(), false, 1, [ 'foo' ], 'foo', 1 ],
'no wancache, one not matching value' =>
[ new EmptyBagOStuff(), true, 1, [ 'bar' ], 'foo', 2 ],
'no wancache, multiple, one matching value' =>
[ new EmptyBagOStuff(), false, 1, [ 'foo', 'bar' ], 'bar', 2 ],
'no wancache, multiple, no matching value' =>
[ new EmptyBagOStuff(), true, 1, [ 'foo', 'bar' ], 'baz', 3 ],
'wancache, empty table' =>
[ new HashBagOStuff(), true, 1, [], 'foo', 1 ],
'wancache, one matching value' =>
[ new HashBagOStuff(), false, 1, [ 'foo' ], 'foo', 1 ],
'wancache, one not matching value' =>
[ new HashBagOStuff(), true, 1, [ 'bar' ], 'foo', 2 ],
'wancache, multiple, one matching value' =>
[ new HashBagOStuff(), false, 1, [ 'foo', 'bar' ], 'bar', 2 ],
'wancache, multiple, no matching value' =>
[ new HashBagOStuff(), true, 1, [ 'foo', 'bar' ], 'baz', 3 ],
];
}
/**
* @dataProvider provideGetAndAcquireId
* @param BagOStuff $cacheBag to use in the WANObjectCache service
* @param bool $needsInsert Does the value we are testing need to be inserted?
* @param int $selectCalls Number of times the select DB method will be called
* @param string[] $existingValues to be added to the db table
* @param string $name name to acquire
* @param int $expectedId the id we expect the name to have
*/
public function testGetAndAcquireId(
$cacheBag,
$needsInsert,
$selectCalls,
$existingValues,
$name,
$expectedId
) {
// Make sure the table is empty!
$this->truncateTable( 'slot_roles' );
$this->populateTable( $existingValues );
$store = $this->getNameTableSqlStore( $cacheBag, (int)$needsInsert, $selectCalls );
// Some names will not initially exist
try {
$result = $store->getId( $name );
$this->assertSame( $expectedId, $result );
} catch ( NameTableAccessException $e ) {
if ( $needsInsert ) {
$this->assertTrue( true ); // Expected exception
} else {
$this->fail( 'Did not expect an exception, but got one: ' . $e->getMessage() );
}
}
// All names should return their id here
$this->assertSame( $expectedId, $store->acquireId( $name ) );
// acquireId inserted these names, so now everything should exist with getId
$this->assertSame( $expectedId, $store->getId( $name ) );
// calling getId again will also still work, and not result in more selects
$this->assertSame( $expectedId, $store->getId( $name ) );
}
public function provideTestGetAndAcquireIdNameNormalization() {
yield [ 'A', 'a', 'strtolower' ];
yield [ 'b', 'B', 'strtoupper' ];
yield [
'X',
'X',
function ( $name ) {
return $name;
}
];
yield [ 'ZZ', 'ZZ-a', __CLASS__ . '::appendDashAToString' ];
}
public static function appendDashAToString( $string ) {
return $string . '-a';
}
/**
* @dataProvider provideTestGetAndAcquireIdNameNormalization
*/
public function testGetAndAcquireIdNameNormalization(
$nameIn,
$nameOut,
$normalizationCallback
) {
$store = $this->getNameTableSqlStore(
new EmptyBagOStuff(),
1,
1,
$normalizationCallback
);
$acquiredId = $store->acquireId( $nameIn );
$this->assertSame( $nameOut, $store->getName( $acquiredId ) );
}
public function provideGetName() {
return [
[ new HashBagOStuff(), 3, 2 ],
[ new EmptyBagOStuff(), 3, 3 ],
];
}
/**
* @dataProvider provideGetName
*/
public function testGetName( $cacheBag, $insertCalls, $selectCalls ) {
// Check for operations to in-memory cache (IMC) and persistent cache (PC)
$store = $this->getNameTableSqlStore( $cacheBag, $insertCalls, $selectCalls );
// Get 1 ID and make sure getName returns correctly
$fooId = $store->acquireId( 'foo' ); // regen PC, set IMC, update IMC, tombstone PC
$this->assertSame( 'foo', $store->getName( $fooId ) ); // use IMC
// Get another ID and make sure getName returns correctly
$barId = $store->acquireId( 'bar' ); // update IMC, tombstone PC
$this->assertSame( 'bar', $store->getName( $barId ) ); // use IMC
// Blitz the cache and make sure it still returns
TestingAccessWrapper::newFromObject( $store )->tableCache = null; // clear IMC
$this->assertSame( 'foo', $store->getName( $fooId ) ); // regen interim PC, set IMC
$this->assertSame( 'bar', $store->getName( $barId ) ); // use IMC
// Blitz the cache again and get another ID and make sure getName returns correctly
TestingAccessWrapper::newFromObject( $store )->tableCache = null; // clear IMC
$bazId = $store->acquireId( 'baz' ); // set IMC using interim PC, update IMC, tombstone PC
$this->assertSame( 'baz', $store->getName( $bazId ) ); // uses IMC
$this->assertSame( 'baz', $store->getName( $bazId ) ); // uses IMC
}
public function testGetName_masterFallback() {
$store = $this->getNameTableSqlStore( new EmptyBagOStuff(), 1, 2 );
// Insert a new name
$fooId = $store->acquireId( 'foo' );
// Empty the process cache, getCachedTable() will now return this empty array
TestingAccessWrapper::newFromObject( $store )->tableCache = [];
// getName should fallback to master, which is why we assert 2 selectCalls above
$this->assertSame( 'foo', $store->getName( $fooId ) );
}
public function testGetMap_empty() {
$this->populateTable( [] );
$store = $this->getNameTableSqlStore( new HashBagOStuff(), 0, 1 );
$table = $store->getMap();
$this->assertSame( [], $table );
}
public function testGetMap_twoValues() {
$this->populateTable( [ 'foo', 'bar' ] );
$store = $this->getNameTableSqlStore( new HashBagOStuff(), 0, 1 );
// We are using a cache, so 2 calls should only result in 1 select on the db
$store->getMap();
$table = $store->getMap();
$expected = [ 1 => 'foo', 2 => 'bar' ];
$this->assertSame( $expected, $table );
// Make sure the table returned is the same as the cached table
$this->assertSame( $expected, TestingAccessWrapper::newFromObject( $store )->tableCache );
}
public function testReloadMap() {
$this->populateTable( [ 'foo' ] );
$store = $this->getNameTableSqlStore( new HashBagOStuff(), 0, 2 );
// force load
$this->assertCount( 1, $store->getMap() );
// add more stuff to the table, so the cache gets out of sync
$this->populateTable( [ 'bar' ] );
$expected = [ 1 => 'foo', 2 => 'bar' ];
$this->assertSame( $expected, $store->reloadMap() );
$this->assertSame( $expected, $store->getMap() );
}
public function testCacheRaceCondition() {
$wanHashBag = new HashBagOStuff();
$store1 = $this->getNameTableSqlStore( $wanHashBag, 1, 1 );
$store2 = $this->getNameTableSqlStore( $wanHashBag, 1, 0 );
$store3 = $this->getNameTableSqlStore( $wanHashBag, 1, 1 );
// Cache the current table in the instances we will use
// This simulates multiple requests running simultaneously
$store1->getMap();
$store2->getMap();
$store3->getMap();
// Store 2 separate names using different instances
$fooId = $store1->acquireId( 'foo' );
$barId = $store2->acquireId( 'bar' );
// Each of these instances should be aware of what they have inserted
$this->assertSame( $fooId, $store1->acquireId( 'foo' ) );
$this->assertSame( $barId, $store2->acquireId( 'bar' ) );
// A new store should be able to get both of these new Ids
// Note: before there was a race condition here where acquireId( 'bar' ) would update the
// cache with data missing the 'foo' key that it was not aware of
$store4 = $this->getNameTableSqlStore( $wanHashBag, 0, 1 );
$this->assertSame( $fooId, $store4->getId( 'foo' ) );
$this->assertSame( $barId, $store4->getId( 'bar' ) );
// If a store with old cached data tries to acquire these we will get the same ids.
$this->assertSame( $fooId, $store3->acquireId( 'foo' ) );
$this->assertSame( $barId, $store3->acquireId( 'bar' ) );
}
public function testGetAndAcquireIdInsertCallback() {
// FIXME: fails under postgres
$this->markTestSkippedIfDbType( 'postgres' );
$store = $this->getNameTableSqlStore(
new EmptyBagOStuff(),
1,
1,
null,
function ( $insertFields ) {
$insertFields['role_id'] = 7251;
return $insertFields;
}
);
$this->assertSame( 7251, $store->acquireId( 'A' ) );
}
}