## Rebalance Storage Between Brokers

For example, after adding or removing brokers from the cluster.

Create a list of topics to move, and put it in `/tmp/topics_to_move.json`:

    {
      "version": 1,
      "topics": [
        {"topic": "sandcrawler-shadow.grobid-output"},
        {"topic": "fatcat-prod.api-crossref"}
      ]
    }

On a kafka broker, go to `/srv/kafka-broker/kafka-*/bin`, generate a plan, then
inspect the output:

    ./kafka-reassign-partitions.sh --zookeeper localhost:2181 --broker-list "280,281,284,285,263" --topics-to-move-json-file /tmp/topics_to_move.json --generate > /tmp/reassignment-plan.json
    cat /tmp/reassignment-plan.json | rg '^\{' | tail -n1 > /tmp/new-plan.json
    cat /tmp/reassignment-plan.json | rg '^\{' | jq .

If that looks good, start the rebalance:

    ./kafka-reassign-partitions.sh --zookeeper localhost:2181 --reassignment-json-file /tmp/new-plan.json --execute

Then monitor progress:

    ./kafka-reassign-partitions.sh --zookeeper localhost:2181 --reassignment-json-file /tmp/new-plan.json --verify