JBoss Cacheの問題点、特徴、その実現方法

http://www.onjava.com/pub/a/onjava/2005/11/09/jboss-pojo-cache.html

記事から一部を抜粋。

既存のキャッシュの問題点

• The user will have to manage the cache specifically.
• The need for Java object serialization could hamper performance. If the object size is huge, even a single field update would trigger serialization of the whole object and replication across the cluster. Thus, it can be unnecessarily expensive.
• Java object serialization cannot preserve the relationship between cached objects. In particular, the cached object cannot be referenced multiple times by other objects (multiple referenced), or have an indirect reference to itself (cyclic). Otherwise, the relationship will be broken upon serialization.

JBoss Cacheの特徴

• There is no explicit API called to manage the cache
• There is no need to implement the Serializable interface for POJOs.
• Replication (or even persistence) is done on a per-field basis (as opposed to the whole object binary level in plain cache), resulting in a potential boost to performance.
• The object relationship and identity are preserved automatically in a distributed replicated environment.

実現方法

実現方法は特には書いてないのだけれど、こんな感じかな。

• 1番目の特徴はAspectで実現
• 2番目の特徴はinstrument時にSerializableインタフェースを実装させることで実現
• 3番目の特徴は、変更されたフィールドをbytecode instrumentionとReflectionを使って検知して、そのフィールドだけをレプリケーションしてパフォーマンス劣化を抑えることで実現
  • 説明も発見. Field Interception.
  • http://docs.jboss.com/jbcache/1.2.4/TreeCacheAop/html/architecture.html

• 4番目の特徴は、どのように実現しているのかいまいちわかってない...