Keep PXC endpoint config by using MySQL instead of Zookeeper.
change mysql_resource table rw_flag column to enum('R', 'W') type
Store mysql resource infomation by using PXC config server instead of zookeeper.
And we still use zookeeper which stores the pxc config server addresses.
Store mysql resource information by using PXC config server instead of zookeeper.
And we still use zookeeper which stores the pxc config server addresses.
Merge branch 'q_dev' of gitlab.corp.qunar.com:corp/dbacess into q_dev
randomly get read connection
Merge branch 'q_dev' into q_master

for new MySQL datasource impl
Add com.qunar.db.resource.Constant class instead of com.qunar.redis.storage.Constant.java