dbcluster: Database Cluster Session Manager
Kris Hardy kris@abqsoft.com
NOTE: This code is in early beta and is under active development. Please use carefully until the code stabalizes into version 1.0 (target: May 2019)
This database engine manager manages master/slave database connections and session management. This is useful for applications which need to manage sqlalchemy database engines and sessionmakers for master/slave database clusters.
Example usage:
import sqlalchemy
from dbcluster import MasterSlaveManager
manager = MasterSlaveManager()
# Set up the master(s)
manager.append_master(
sqlalchemy.create_engine('postgresql://127.0.0.1:5432'),
orm=MasterSlaveManager.ORM_SQLALCHEMY
)
# Set up slaves
manager.append_slave(
sqlalchemy.create_engine('postgresql://127.0.0.1:5433'),
orm=MasterSlaveManager.ORM_SQLALCHEMY
)
manager.append_slave(
sqlalchemy.create_engine('postgresql://127.0.0.1:5435'),
orm=MasterSlaveManager.ORM_SQLALCHEMY
)
# Use the database sessions
with manager.master_session_ctx() as db_session:
# Do something with the session ...
db_session.commit()
with manager.slave_session_ctx() as db_session:
# Returns a random slave session
# Do something with the session ...
db_session.commit()
with manager.slave_session_ctx(0) as db_session:
# Returns a session to the first slave
# Do something with the session ...
db_session.commit()
