ActiveMQ -- leveldb of persistence mechanism

LevelDB（ understand ）

LevelDB Is in activemq 5.8 Introduced after version , and KahaDB similar , It is also a local database storage form based on file , But more than KahaDB Faster persistence . No customized B-Tree Implement index to write log , It's based on LevelDB The index of , because “append only” File access mode , Have better properties ：

• Quick update ( Random disk updates are not required )
• Concurrent reads
• Quick index snapshots using hard links

Be careful ：

Warning

The LevelDB store has been deprecated and is no longer supported or recommended for use. The recommended store is KahaDB

however ,ActiveMQ V5.14.2 The version began to be discarded LevelDB, And in V5.17.0 Version deleted LevelDB, Official recommendation or use KahaDB.

The default configuration is as follows ,activemq.xml file ：

<persistenceAdapter>
    <levelDB directory="activemq-data" />
</persistenceAdapter>