Redis Cache
By default, Quarkus Cache uses Caffeine as backend. It’s possible to use Redis instead.
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This technology is considered preview. In preview, backward compatibility and presence in the ecosystem is not guaranteed. Specific improvements might require changing configuration or APIs, and plans to become stable are under way. Feedback is welcome on our mailing list or as issues in our GitHub issue tracker. For a full list of possible statuses, check our FAQ entry. |
Redis as cache backend
When using Redis as the backend for Quarkus cache, each cached item will be stored in Redis:
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The backend uses the <default> Redis client (if not configured otherwise), so make sure it’s configured (or use the Redis Dev Service)
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the Redis key is built as follows:
cache:$cache-name:$cache-key, wherecache-keyis the key the application uses. -
the value is encoded to JSON if needed
Use the Redis backend
First, you need to add the quarkus-redis-cache extension to your project:
<dependency>
<groupId>io.quarkus</groupId>
<artifactId>quarkus-redis-cache</artifactId>
</dependency>implementation("io.quarkus:quarkus-redis-cache")Then, use the @CacheResult and others cache annotations as explained in the Quarkus Cache guide:
@GET
@Path("/{keyElement1}/{keyElement2}/{keyElement3}")
@CacheResult(cacheName = "expensiveResourceCache")
public ExpensiveResponse getExpensiveResponse(@PathParam("keyElement1") @CacheKey String keyElement1,
@PathParam("keyElement2") @CacheKey String keyElement2, @PathParam("keyElement3") @CacheKey String keyElement3,
@QueryParam("foo") String foo) {
invocations.incrementAndGet();
ExpensiveResponse response = new ExpensiveResponse();
response.setResult(keyElement1 + " " + keyElement2 + " " + keyElement3 + " too!");
return response;
}
@POST
@CacheInvalidateAll(cacheName = "expensiveResourceCache")
public void invalidateAll() {
}Configure the Redis backend
The Redis backend uses the <default> Redis client.
See the Redis reference to configure the access to Redis.
| In dev mode, you can use the Redis Dev Service. |
If you want to use another Redis for your cache, configure the client-name as follows:
quarkus.cache.redis.client-name=my-redis-for-cacheWhen writing to Redis or reading from Redis, Quarkus needs to know the type. Indeed, the objects need to be serialized and deserialized. For that purpose, you may need to configure type (class names) of the key and value you want to cache. At build time, Quarkus tries to deduce the types from the application code, but that decision can be overridden using:
# Default configuration
quarkus.cache.redis.key-type=java.lang.String
quarkus.cache.redis.value-type=org.acme.Person
# Configuration for `expensiveResourceCache`
quarkus.cache.redis.expensiveResourceCache.key-type=java.lang.String
quarkus.cache.redis.expensiveResourceCache.value-type=org.acme.SupesYou can also configure the time to live of the cached entries:
# Default configuration
quarkus.cache.redis.expire-after-write=10s
# Configuration for `expensiveResourceCache`
quarkus.cache.redis.expensiveResourceCache.expire-after-write=1hIf the expire-after-write is not configured, the entry won’t be evicted.
You would need to invalidate the values using the @CacheInvalidateAll or @CacheInvalidate annotations.
The following table lists the supported properties:
Configuration property fixed at build time - All other configuration properties are overridable at runtime
Configuration property |
Type |
Default |
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The name of the named Redis client to be used for communicating with Redis. If not set, use the default Redis client. Environment variable: Show more |
string |
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The default type of the value stored in the cache. Environment variable: Show more |
string |
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The key type, Environment variable: Show more |
string |
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Specifies that each entry should be automatically removed from the cache once a fixed duration has elapsed after the entry’s creation, or the most recent replacement of its value. Environment variable: Show more |
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Specifies that each entry should be automatically removed from the cache once a fixed duration has elapsed after the last access of its value. Environment variable: Show more |
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the key prefix allowing to identify the keys belonging to the cache. If not set, use "cache:$cache-name" Environment variable: Show more |
string |
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Whether the access to the cache should be using optimistic locking. See Redis Optimistic Locking for details. Default is Environment variable: Show more |
boolean |
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Additional configuration applied to a specific Redis cache (highest precedence) |
Type |
Default |
The default type of the value stored in the cache. Environment variable: Show more |
string |
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The key type, Environment variable: Show more |
string |
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Specifies that each entry should be automatically removed from the cache once a fixed duration has elapsed after the entry’s creation, or the most recent replacement of its value. Environment variable: Show more |
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Specifies that each entry should be automatically removed from the cache once a fixed duration has elapsed after the last access of its value. Environment variable: Show more |
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the key prefix allowing to identify the keys belonging to the cache. If not set, use "cache:$cache-name" Environment variable: Show more |
string |
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Whether the access to the cache should be using optimistic locking. See Redis Optimistic Locking for details. Default is Environment variable: Show more |
boolean |
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About the Duration format
To write duration values, use the standard You can also use a simplified format, starting with a number:
In other cases, the simplified format is translated to the
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Configure the Redis key
By default, the Redis backend stores the entry using the following keys: cache:$cache-name:$cache-key, where cache-key is the key the application uses.
So, you can find all the entries for a single cache using the Redis KEYS command: KEYS cache:$cache-name:*
The cache:$cache-name: segment can be configured using the prefix property:
# Default configuration
quarkus.cache.redis.prefix=my-cache
# Configuration for `expensiveResourceCache`
quarkus.cache.redis.expensiveResourceCache.prefix=my-expensive-cacheIn these cases, you can find all the keys managed by the default cache using KEYS my-cache:*, and all the keys managed by the expensiveResourceCache cache using: KEYS my-expensive-cache:*.
Enable optimistic locking
The access to the cache can be direct or use optimistic locking. By default, optimistic locking is disabled.
You can enable optimistic locking using:
# Default configuration
quarkus.cache.redis.use-optimistic-locking=true
# Configuration for `expensiveResourceCache`
quarkus.cache.redis.expensiveResourceCache.use-optimistic-locking=trueWhen used, the key is watched and the SET command is executed in a transaction (MULTI/EXEC).
