2pc 3pc

http://www.cnblogs.com/shangxiaofei/p/5196260.html
http://blog.csdn.net/u010191243/article/details/52081891
http://blog.csdn.net/whycold/article/details/ 47702133
http://blog.csdn.net/forever_wind/article/details/37506027 After failure of
2pc
process 1 or 2: the coordinator will send an abort message.