Redis Cache Adapter ¶
See also
This article explains how to configure the Redis adapter when using the Cache as an independent component in any PHP application. Read the Symfony Cache configuration article if you are using it in a Symfony application.
This adapter stores the values in-memory using one (or more) Redis server instances.
Unlike the APCu adapter, and similarly to the Memcached adapter, it is not limited to the current server's shared memory; you can store contents independent of your PHP environment. The ability to utilize a cluster of servers to provide redundancy and/or fail-over is also available.
Caution
Requirements: At least one Redis server must be installed and running to use this
adapter. Additionally, this adapter requires a compatible extension or library that implements
\Redis
, \RedisArray
, RedisCluster
, or \Predis
.
This adapter expects a Redis, RedisArray, RedisCluster, or Predis instance to be passed as the first parameter. A namespace and default cache lifetime can optionally be passed as the second and third parameters:
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use Symfony\Component\Cache\Adapter\RedisAdapter;
$cache = new RedisAdapter(
// the object that stores a valid connection to your Redis system
\Redis $redisConnection,
// the string prefixed to the keys of the items stored in this cache
$namespace = '',
// the default lifetime (in seconds) for cache items that do not define their
// own lifetime, with a value 0 causing items to be stored indefinitely (i.e.
// until RedisAdapter::clear() is invoked or the server(s) are purged)
$defaultLifetime = 0
);
|
Configure the Connection ¶
The createConnection() helper method allows creating and configuring the Redis client class instance using a Data Source Name (DSN):
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use Symfony\Component\Cache\Adapter\RedisAdapter;
// pass a single DSN string to register a single server with the client
$client = RedisAdapter::createConnection(
'redis://localhost'
);
|
The DSN can specify either an IP/host (and an optional port) or a socket path, as well as a
password and a database index. To enable TLS for connections, the scheme redis
must be
replaced by rediss
(the second s
means "secure").
Note
A Data Source Name (DSN) for this adapter must use either one of the following formats.
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redis[s]://[pass@][ip|host|socket[:port]][/db-index]
|
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redis[s]:[[user]:pass@]?[ip|host|socket[:port]][¶ms]
|
Values for placeholders [user]
, [:port]
, [/db-index]
and [¶ms]
are optional.
Below are common examples of valid DSNs showing a combination of available values:
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use Symfony\Component\Cache\Adapter\RedisAdapter;
// host "my.server.com" and port "6379"
RedisAdapter::createConnection('redis://my.server.com:6379');
// host "my.server.com" and port "6379" and database index "20"
RedisAdapter::createConnection('redis://my.server.com:6379/20');
// host "localhost", auth "abcdef" and timeout 5 seconds
RedisAdapter::createConnection('redis://abcdef@localhost?timeout=5');
// socket "/var/run/redis.sock" and auth "bad-pass"
RedisAdapter::createConnection('redis://bad-pass@/var/run/redis.sock');
// host "redis1" (docker container) with alternate DSN syntax and selecting database index "3"
RedisAdapter::createConnection('redis:?host[redis1:6379]&dbindex=3');
// providing credentials with alternate DSN syntax
RedisAdapter::createConnection('redis:default:verysecurepassword@?host[redis1:6379]&dbindex=3');
// a single DSN can also define multiple servers
RedisAdapter::createConnection(
'redis:?host[localhost]&host[localhost:6379]&host[/var/run/redis.sock:]&auth=my-password&redis_cluster=1'
);
|
Redis Sentinel, which provides high availability for Redis, is also supported
when using the PHP Redis Extension v5.2+ or the Predis library. Use the redis_sentinel
parameter to set the name of your service group:
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RedisAdapter::createConnection(
'redis:?host[redis1:26379]&host[redis2:26379]&host[redis3:26379]&redis_sentinel=mymaster'
);
// providing credentials
RedisAdapter::createConnection(
'redis:default:verysecurepassword@?host[redis1:26379]&host[redis2:26379]&host[redis3:26379]&redis_sentinel=mymaster'
);
// providing credentials and selecting database index "3"
RedisAdapter::createConnection(
'redis:default:verysecurepassword@?host[redis1:26379]&host[redis2:26379]&host[redis3:26379]&redis_sentinel=mymaster&dbindex=3'
);
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Note
See the RedisTrait for more options you can pass as DSN parameters.
Configure the Options ¶
The createConnection() helper method
also accepts an array of options as its second argument. The expected format is an associative
array of key => value
pairs representing option names and their respective values:
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use Symfony\Component\Cache\Adapter\RedisAdapter;
$client = RedisAdapter::createConnection(
// provide a string dsn
'redis://localhost:6379',
// associative array of configuration options
[
'class' => null,
'persistent' => 0,
'persistent_id' => null,
'timeout' => 30,
'read_timeout' => 0,
'retry_interval' => 0,
'tcp_keepalive' => 0,
'lazy' => null,
'redis_cluster' => false,
'redis_sentinel' => null,
'dbindex' => 0,
'failover' => 'none',
'ssl' => null,
]
);
|
Available Options ¶
class
(type:string
, default:null
)-
Specifies the connection library to return, either
\Redis
or\Predis\Client
. If none is specified, it will return\Redis
if theredis
extension is available, and\Predis\Client
otherwise. Explicitly set this to\Predis\Client
for Sentinel if you are running into issues when retrieving master information.返す接続ライブラリを \Redis または \Predis\Client のいずれかで指定します。何も指定されていない場合、redis 拡張機能が利用可能な場合は \Redis を返し、それ以外の場合は \Predis\Client を返します。マスター情報を取得するときに問題が発生している場合は、これを \Predis\Client for Sentinel に明示的に設定します。 persistent
(type:int
, default:0
)-
Enables or disables use of persistent connections. A value of
0
disables persistent connections, and a value of1
enables them.永続的な接続の使用を有効または無効にします。値 0 は永続接続を無効にし、値 1 はそれらを有効にします。 persistent_id
(type:string|null
, default:null
)-
Specifies the persistent id string to use for a persistent connection.
永続的な接続に使用する永続的な ID 文字列を指定します。
timeout
(type:int
, default:30
)-
Specifies the time (in seconds) used to connect to a Redis server before the
connection attempt times out.
接続試行がタイムアウトするまでに Redis サーバーへの接続に使用される時間 (秒単位) を指定します。
read_timeout
(type:int
, default:0
)-
Specifies the time (in seconds) used when performing read operations on the underlying
network resource before the operation times out.
基になるネットワーク リソースで読み取り操作を実行するときに、操作がタイムアウトするまでの時間 (秒単位) を指定します。
retry_interval
(type:int
, default:0
)-
Specifies the delay (in milliseconds) between reconnection attempts in case the client
loses connection with the server.
クライアントがサーバーとの接続を失った場合の再接続試行間の遅延 (ミリ秒単位) を指定します。
tcp_keepalive
(type:int
, default:0
)-
Specifies the TCP-keepalive timeout (in seconds) of the connection. This
requires phpredis v4 or higher and a TCP-keepalive enabled server.
接続の TCP キープアライブ タイムアウト (秒単位) を指定します。これには、phpredis v4 以降と TCP キープアライブ対応サーバーが必要です。
lazy
(type:bool
, default:null
)-
Enables or disables lazy connections to the backend. It's
false
by default when using this as a stand-alone component andtrue
by default when using it inside a Symfony application.バックエンドへの遅延接続を有効または無効にします。これをスタンドアロン コンポーネントとして使用する場合はデフォルトで false であり、Symfony アプリケーション内で使用する場合はデフォルトで true です。 redis_cluster
(type:bool
, default:false
)-
Enables or disables redis cluster. The actual value passed is irrelevant as long as it passes loose comparison
checks: `redis_cluster=1` will suffice.
redis クラスターを有効または無効にします。渡される実際の値は、緩やかな比較チェックに合格する限り、無関係です: `redis_cluster=1` で十分です。
redis_sentinel
(type:string
, default:null
)-
Specifies the master name connected to the sentinels.
センチネルに接続されたマスター名を指定します。
dbindex
(type:int
, default:0
)-
Specifies the database index to select.
選択するデータベース インデックスを指定します。
failover
(type:string
, default:none
)-
Specifies failover for cluster implementations. For
\RedisCluster
valid options arenone
(default),error
,distribute
orslaves
. For\Predis\ClientInterface
valid options areslaves
ordistribute
.クラスター実装のフェイルオーバーを指定します。 \RedisCluster の場合、有効なオプションは none (デフォルト)、error、distribute、または slaves です。 ssl
(type:bool
, default:null
)-
SSL context options. See php.net/context.ssl for more information.
SSL コンテキスト オプション。詳細については、php.net/context.ssl を参照してください。
Note
When using the Predis library some additional Predis-specific options are available. Reference the Predis Connection Parameters documentation for more information.
Working with Tags ¶
In order to use tag-based invalidation, you can wrap your adapter in TagAwareAdapter, but when Redis is used as backend, it's often more interesting to use the dedicated RedisTagAwareAdapter. Since tag invalidation logic is implemented in Redis itself, this adapter offers better performance when using tag-based invalidation:
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use Symfony\Component\Cache\Adapter\RedisAdapter;
use Symfony\Component\Cache\Adapter\RedisTagAwareAdapter;
$client = RedisAdapter::createConnection('redis://localhost');
$cache = new RedisTagAwareAdapter($client);
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Configuring Redis ¶
When using Redis as cache, you should configure the maxmemory
and maxmemory-policy
settings. By setting maxmemory
, you limit how much memory Redis is allowed to consume.
If the amount is too low, Redis will drop entries that would still be useful and you benefit
less from your cache. Setting the maxmemory-policy
to allkeys-lru
tells Redis that
it is ok to drop data when it runs out of memory, and to first drop the oldest entries (least
recently used). If you do not allow Redis to drop entries, it will return an error when you
try to add data when no memory is available. An example setting could look as follows:
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maxmemory 100mb
maxmemory-policy allkeys-lru
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Read more about this topic in the official Redis LRU Cache Documentation.