Introduction

A high available BTM transaction logs journal using bookkeeper. It's still under heavy development.

BTM: http://docs.codehaus.org/display/BTM/Home

BookKeeper: http://zookeeper.apache.org/bookkeeper/svn.html

License

BTM is LGPL license based,so is ewok.

#Internal

Ewok use zookeeper to store every TransactionManager's ledger id:

 /ewok
	/app1
			/192-168-1-100 -- 0		[ledger id]
				 /ownership	            [Ephemeral node]
			/192-168-1-101 -- 1
			  	 /ownership
	/app2
			/192-168-1-135 -- 99
			/192-168-1-136 -- 100
				/ownership
			......

And ewok use bookkeeper to write transaction logs,it writes a TransactionLogRecord as an entry to ledger.If it write failed,it just create a new ledger and copy all dangling transactions to the new ledger.

#Configuration

Ewok use a config file named ewok-config.properties to configure it's properties:

 #zookeepere servers
 ewok.zkServers=localhost:2181
 #special server id for this tm,default is local address
 ewok.serverId=test
 #zookeeper namespace
 ewok.zkRoot=ewok
 #zookeeper session timeout
 ewok.zkSessionTimeout=5000
 #A path to load other TM's logs,default is null
 ewok.loadZkPath=
 #Ledger ensemble size
 ewok.ensembleSize=1
 #Ledger quorum size
 ewok.quorumSize=1
 #Ledger password
 ewok.password=ewok
 #Batch size to read entries from ledger
 ewok.cursorBatchSize=5