Demystifying cache in Doctrine ORM (v2)

Applications should be fast regardless of any cache system. However, sometimes we do need to cache data in order to optimise things and deliver a fast response to the clients.
This talk covers the different types of cache offered Doctrine ORM (metadata, query, result set, and second level cache), how they work together with the Unit of Work and what we should know before caching all the things.

Transcript

1. Demystifying
   Luís Cobucci

   @lcobucci
   https://goo.gl/oZPuRc
   cache in Doctrine ORM
   

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2. Reliability
   https://goo.gl/1shwsY
   

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3. Maintainability
   https://goo.gl/D4DvKC
   

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4. Scalability
   https://goo.gl/M67mS8
   

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5. Trade-offs
   https://goo.gl/L7YdSp
   

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6. Minions of users!
   https://goo.gl/7MAkHZ
   

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7. Luís Cobucci

   @lcobucci
   https://jobs.usabilla.com
   

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8. Doctrine ORM?
   https://goo.gl/xCBz84
   

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9. Template
   Message
   Customer
   Campaign
   1
   1
   1
   *
   *
   *
   

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10. Template
    Message
    Customer
    Campaign
    1
    1
    1
    *
    *
    *
    

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11. Template
    Message
    Customer
    Campaign
    1
    1
    1
    *
    *
    *
    

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12. Template
    Message
    Customer
    Campaign
    1
    1
    1
    *
    *
    *
    Order
    matters
    

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13. Template
    Message
    Customer
    Campaign
    1
    1
    1
    *
    *
    *
    INSERT INTO customer (name, email)

    VALUES (“Luís Cobucci”, “luis@me.com”);

    SET @customer_id = LAST_INSERT_ID();
    

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14. Template
    Message
    Customer
    Campaign
    1
    1
    1
    *
    *
    *
    INSERT INTO customer (name, email)

    VALUES (“Luís Cobucci”, “luis@me.com”);

    SET @customer_id = LAST_INSERT_ID();
    INSERT INTO template (name, body)

    VALUES (“Template 1”, “blah… blah… blah…”);
    

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15. Template
    Message
    Customer
    Campaign
    1
    1
    1
    *
    *
    *
    INSERT INTO customer (name, email)

    VALUES (“Luís Cobucci”, “luis@me.com”);

    SET @customer_id = LAST_INSERT_ID();
    INSERT INTO template (name, body)

    VALUES (“Template 1”, “blah… blah… blah…”);
    INSERT INTO campaign (title, template_id, message)

    VALUES (“Test”, LAST_INSERT_ID(), “blah… blah… blah…”);
    

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16. Template
    Message
    Customer
    Campaign
    1
    1
    1
    *
    *
    *
    INSERT INTO customer (name, email)

    VALUES (“Luís Cobucci”, “luis@me.com”);

    SET @customer_id = LAST_INSERT_ID();
    INSERT INTO template (name, body)

    VALUES (“Template 1”, “blah… blah… blah…”);
    INSERT INTO campaign (title, template_id, message)

    VALUES (“Test”, LAST_INSERT_ID(), “blah… blah… blah…”);
    INSERT INTO message (campaign_id, customer_id, sent)

    VALUES (LAST_INSERT_ID(), @customer_id, FALSE);
    

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17. Template
    Message
    Customer
    Campaign
    1
    1
    1
    *
    *
    *
    INSERT INTO customer (name, email)

    VALUES (“Luís Cobucci”, “luis@me.com”);

    SET @customer_id = LAST_INSERT_ID();
    INSERT INTO template (name, body)

    VALUES (“Template 1”, “blah… blah… blah…”);
    INSERT INTO campaign (title, template_id, message)

    VALUES (“Test”, LAST_INSERT_ID(), “blah… blah… blah…”);
    INSERT INTO message (campaign_id, customer_id, sent)

    VALUES (LAST_INSERT_ID(), @customer_id, FALSE);
    Don’t forget to use a
    transaction!
    

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18. EntityManager
    persist()
    flush()
    find()
    remove()
    

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19. declare(strict_types=1);
    $customer = new Customer('Luís Cobucci', 'luis@me.com');

    $template = new Template('Template 1', 'blah… blah… blah…');

    $campaign = new Campaign($template, 'Test', 'blah… blah… blah…');

    $message = new Message($campaign, $customer);

    

    $entityManager->persist($customer);
    $entityManager->persist($template);
    $entityManager->persist($campaign);
    $entityManager->persist($message);
    $entityManager->flush();
    

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20. EntityManager UnitOfWork DB
    

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21. declare(strict_types=1);
    $customer = $entityManager->find('Customer', 2);
    $campaign = $entityManager->find('Campaign', 1);

    

    $entityManager->persist(new Message($campaign, $customer));
    $entityManager->flush();
    

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22. http://goo.gl/gH0hsx
    Amazing, right?
    

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23. “ORMs are slow!”
    https://goo.gl/dRfUyZ
    

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24. https://goo.gl/91u2rx
    

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25. https://goo.gl/SAH57F
    Big ball of mud
    

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26. https://goo.gl/d3DNXm
    Hydration
    

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27. https://goo.gl/hr22Dx
    Outdated
    

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28. https://goo.gl/1y3fvm
    Bugs…
    

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29. https://goo.gl/cuLYT9
    Bugs…
    

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30. https://goo.gl/D3Gw7e
    Bugs…
    

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31. Make it fast!
    https://goo.gl/6Y2kQd
    

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32. “ a hardware or software component
    that stores data so future requests for
    that data can be served faster; the data
    stored in a cache might be the result of
    an earlier computation, or the duplicate
    of data stored elsewhere.
    Cache (computing) - Wikipedia
    

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33. Our software
    Cache
    External API
    

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34. Our software
    Cache
    External API
    1. Give me
    “external.result”
    

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35. Our software
    Cache
    External API
    2. Cache miss
    1. Give me
    “external.result”
    

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36. Our software
    Cache
    External API
    2. Cache miss
    3. Give me
    data
    1. Give me
    “external.result”
    

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37. Our software
    Cache
    External API
    2. Cache miss
    3. Give me
    data
    4. There you
    go
    1. Give me
    “external.result”
    

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38. Our software
    Cache
    External API
    2. Cache miss
    1. Give me
    “external.result”
    3. Give me
    data
    4. There you
    go
    5. Store
    “external.result”
    

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39. Our software
    Cache
    External API
    2. Cache miss
    1. Give me
    “external.result”
    3. Give me
    data
    4. There you
    go
    5. Store
    “external.result” 6. Stored!
    

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40. Our software
    Cache
    External API
    1. Give me
    “external.result”
    

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41. Our software
    Cache
    External API
    2. Cache hit!
    1. Give me
    “external.result”
    

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42. Our software
    Cache
    External API
    2. Cache hit!
    1. Give me
    “external.result”
    When should we invalidate
    the cache?
    

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43. “ There are two hard things in
    Computer Science: cache invalidation,
    naming things, and off-by-one errors
    Common sense
    

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44. Metadata
    https://goo.gl/AhjBFJ
    

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45. /** @ORM\Entity */
    class Customer

    {

    /** 

    * @ORM\Id

    * @ORM\GeneratedValue 

    * @ORM\Column(type="integer")

    */
    private $id;

    

    /** @ORM\Column(type="string") */

    private $name;

    

    /** @ORM\Column(type="string") */

    private $email;
    }
    

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46. /** @ORM\Entity */
    class Customer

    {

    /** 

    * @ORM\Id

    * @ORM\GeneratedValue 

    * @ORM\Column(type="integer")

    */
    private $id;

    

    /** @ORM\Column(type="string") */

    private $name;

    

    /** @ORM\Column(type="string") */

    private $email;
    }
    ClassMetadata
    

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47. declare(strict_types=1);
    use Doctrine\Common\Cache\RedisCache;
    use Doctrine\ORM\Configuration;
    $metadataCache = new RedisCache();
    $configuration = new Configuration();
    // …
    $configuration->setMetadataCacheImpl($metadataCache);
    

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48. Query
    https://goo.gl/nuFRba
    

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49. SELECT customer FROM Customer customer;
    

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50. SELECT customer FROM Customer customer;
    SELECT

    c0.id AS id_0,

    c0.name AS name_1,
    c0.email AS email_2,

    FROM customer c0;
    

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51. declare(strict_types=1);
    $builder = $entityManager->createQueryBuilder()

    ->select(‘customer’)
    ->from(Customer::class, ‘customer');
    $query = $builder->getQuery();

    $result = $query->getResult();
    

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52. declare(strict_types=1);
    use Doctrine\Common\Cache\RedisCache;
    use Doctrine\ORM\Configuration;
    $queryCache = new RedisCache();
    $configuration = new Configuration();
    // …
    $configuration->setQueryCacheImpl($queryCache);
    

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53. declare(strict_types=1);
    $builder = $entityManager->createQueryBuilder()

    ->select(‘customer’)
    ->from(Customer::class, ‘customer');
    if (isset($params[‘email’])) {
    $builder->where(‘customer.email = :email’)

    ->setParameter(‘email’, $params[‘email’]);
    }
    $query = $builder->getQuery();

    $result = $query->getResult();
    

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54. Result set
    https://goo.gl/7yah7S
    

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55. $query = 'SELECT COUNT(m) FROM Message m WHERE m.user = :user';
    

    $count = $entityManager->createQuery($query)

    ->setParameter('user', 1)

    ->getSingleScalarResult();
    

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56. declare(strict_types=1);
    use Doctrine\Common\Cache\RedisCache;
    use Doctrine\ORM\Configuration;
    $queryCache = new RedisCache();
    $configuration = new Configuration();
    // …
    $configuration->setQueryCacheImpl($queryCache);
    

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57. $query = 'SELECT COUNT(m) FROM Message m WHERE m.user = :user';
    

    $count = $entityManager->createQuery($query)

    ->setParameter('user', 1)

    ->useResultCache(true, 3600)

    ->getSingleScalarResult();
    

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58. L2C
    https://goo.gl/8pbG3y
    

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59. EntityManager UnitOfWork DB
    

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60. declare(strict_types=1);
    use Doctrine\Common\Cache\RedisCache;
    use Doctrine\ORM\Cache as L2C;
    use Doctrine\ORM\Configuration;
    $level2Cache = new RedisCache();
    $level2Config = new L2C\CacheConfiguration();
    $level2Config->setSecondLevelCacheEnabled(
    new L2C\DefaultCacheFactory(
    new L2C\RegionsConfiguration(),
    $level2Cache
    )
    );
    $configuration = new Configuration();
    // …
    $configuration->setSecondLevelCacheEnabled(true);
    $configuration->setSecondLevelCacheConfiguration($level2Config);
    

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61. EntityManager UnitOfWork L2C
    DB
    

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62. L2C
    Collection
    Entity Query
    

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63. /**

    * @ORM\Entity

    * @ORM\Cache(usage="NONSTRICT_READ_WRITE")

    */
    class Customer

    {

    // …

    }
    

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64. /**

    * @ORM\Entity

    * @ORM\Cache(usage="NONSTRICT_READ_WRITE")

    */
    class Customer

    {

    // …

    }
    READ_ONLY

    NONSTRICT_READ_WRITE

    READ_WRITE
    

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65. /**

    * @ORM\Entity

    * @ORM\Cache(usage="NONSTRICT_READ_WRITE")

    */
    class Message

    {

    // …

    

    /**

    * @ORM\ManyToOne(targetEntity="Customer")
    * @ORM\Cache(usage="READ_ONLY")
    */

    private $customer;
    

    // …

    }
    

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66. $query = ‘SELECT m FROM Message m WHERE m.customer = :id’;
    

    $messages = $entityManager->createQuery($query)

    ->setParameter(‘id', 1)

    ->setCacheable(true)

    ->getResult();
    

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67. https://goo.gl/bGP8u8
    Intense traffic
    

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68. https://goo.gl/bGP8u8
    Upcoming!
    

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69. Demystifying
    Luís Cobucci

    @lcobucci
    https://goo.gl/oZPuRc
    cache in Doctrine ORM
    

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70. Thanks!
    @lcobucci
    

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