RBF supports two types of StateStoreDrivers
I propose implementing a third driver that is backed by MySQL.
- StateStoreZooKeeperImpl requires an additional Zookeeper cluster.
- StateStoreFileImpl can use one of the namenodes in the HDFS cluster, but that namenode becomes a single point of failure, introducing coupling between the federated clusters.
HADOOP-18535 implemented a MySQL token store. When tokens are stored in MySQL, using MySQL for the StateStore as well reduces the number of external dependencies for routers.