isabella232 / python-citus-rebalancer

A python command line tool to recommend shard moves to customers with unbalanced clusters

python-citus-rebalancer

A python command to get recommendations on commands to run to rebalance an unbalaned citus cluster.

Sometimes when your cluster grows, you can have an uneven size on nodes: for example if one customers ingests more data than other. This simple commands helps you figure out what master_move_shard commands to run on your coordinator.

Installation

Install with pip install

1. Run pip install py-citus-rebalancer

Install from source code

1. Clone the github repository
2. Run python setup.py develop

Running the command

This command has different options:

• --host: is your postgres connection string
• --delta: is the maximum difference you expect between the node size and the idea size. For example if you have 4 nodes and 20GB of data, the idea size would be 5GB per node. The delta that you can give is for example 10% difference. It's an integer representing the percent.
• --file: path to the file where you want the command to be written: example /path/to/rebalance.sql. You can then run the file on your coordinator

1. Run the command citus-rebalancer --host=postgres://user:pwd@host:5432/dbname --delta=10
2. It will return commands to run, run them on your coordinator to rebalance the cluster.