# Redis based MyBatis Cache implementation
Implements [MyBatis Cache ](https://mybatis.org/mybatis-3/sqlmap-xml.html#cache ) provider based on Redis.
Compatible with MyBatis 3.0.0+
Redisson provides various MyBatis Cache implementations including those with features below:
**local cache** - so called `near cache` , which is useful for use cases when MyBatis Cache used mostly for read operations and/or network roundtrips are undesirable. It caches Map entries on Redisson side and executes read operations up to **45x faster** in comparison with common implementation. All local caches with the same name connected to the same pub/sub channel which is used for messaging between them. In particular to send entity update or entity invalidate event.
**data partitioning** - data partitioning in cluster mode. It allows to scale available memory, read/write operations and entry eviction process for individual MyBatis Cache instance in Redis cluster.
Below is the list of all available implementations with local cache and/or data partitioning support:
|Class name | Local cache < br / > support< br / > (up to 45x faster) | Data partitioning < br / > support |
| ------------- | ------------- | ------------|
|RedissonCache< br / > | No | No |
|RedissonLocalCachedCache< br />< sub >< i > available only in [Redisson PRO ](http://redisson.pro ) edition</ i ></ sub > | **Yes** | No |
|RedissonClusteredCache< br />< sub >< i > available only in [Redisson PRO ](http://redisson.pro ) edition</ i ></ sub > | No | **Yes** |
|RedissonClusteredLocalCachedCache< br />< sub >< i > available only in [Redisson PRO ](http://redisson.pro ) edition</ i ></ sub > | **Yes** | **Yes** |
## MyBatis Cache Usage
### 1. Add `redisson-mybatis` dependency into your project:
Maven
```xml
< dependency >
< groupId > org.redisson< / groupId >
< artifactId > redisson-mybatis< / artifactId >
< version > 3.11.7< / version >
< / dependency >
```
Gradle
```groovy
compile 'org.redisson:redisson-mybatis:3.11.7'
```
### 2. Specify MyBatis cache settings
Redisson allows to define follow settings per Cache instance:
`timeToLive` - defines time to live per cache entry
`maxIdleTime` - defines max idle time per cache entry
`maxSize` - defines max size of entries amount stored in Redis
`localCacheEvictionPolicy` - local cache eviction policy. `LFU` , `LRU` , `SOFT` , `WEAK` and `NONE` eviction policies are available.
`localCacheSize` - local cache size. If size is `0` then local cache is unbounded.
`localCacheTimeToLive` - time to live in milliseconds for each map entry in local cache. If value equals to `0` then timeout is not applied.
`localCacheMaxIdleTime` - max idle time in milliseconds for each map entry in local cache. If value equals to `0` then timeout is not applied.
`localCacheSyncStrategy` - local cache sync strategy. `INVALIDATE` , `UPDATE` and `NONE` eviction policies are available.
`redissonConfig` - defines path to redisson config in YAML format
Examples:
```xml
< cache type = "org.redisson.hibernate.RedissonCache" >
< property name = "timeToLive" value = "200000" / >
< property name = "maxIdleTime" value = "100000" / >
< property name = "maxSize" value = "100000" / >
< property name = "redissonConfig" value = "redisson.yaml" / >
< / cache >
<!-- or -->
< cache type = "org.redisson.hibernate.RedissonLocalCachedCache" >
< property name = "timeToLive" value = "200000" / >
< property name = "maxIdleTime" value = "100000" / >
< property name = "maxSize" value = "100000" / >
< property name = "redissonConfig" value = "redisson.yaml" / >
< / cache >
<!-- or -->
< cache type = "org.redisson.hibernate.RedissonClusteredCache" >
< property name = "timeToLive" value = "200000" / >
< property name = "maxIdleTime" value = "100000" / >
< property name = "maxSize" value = "100000" / >
< property name = "redissonConfig" value = "redisson.yaml" / >
< / cache >
<!-- or -->
< cache type = "org.redisson.hibernate.RedissonClusteredLocalCachedCache" >
< property name = "timeToLive" value = "200000" / >
< property name = "maxIdleTime" value = "100000" / >
< property name = "maxSize" value = "100000" / >
< property name = "redissonConfig" value = "redisson.yaml" / >
< / cache >
```
