[KAFKA-16455] Check partition exists before send reassignments to server in ReassignPartitionsCommand

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 3.8.0
• Component/s: tools
• Assignee: Kuan Po Tseng
• Reporter: Kuan Po Tseng
• Created: 01/Apr/24 16:11
• Updated: 08/Apr/24 23:57
• Resolved: 08/Apr/24 23:57

Description

Currently, when executing kafka-reassign-partitions.sh with the --execute option, if a partition number specified in the JSON file does not exist, this check occurs only when submitting the reassignments to alterPartitionReassignments on the server-side.

We can perform this check in advance before submitting the reassignments to the server side.

For example, suppose we have three brokers with IDs 1001, 1002, and 1003, and a topic named first_topic with only three partitions. And execute 

bin/kafka-reassign-partitions.sh 
  --bootstrap-server 192.168.0.128:9092 
  --reassignment-json-file reassignment.json 
  --execute

Where reassignment.json contains

{
  "version": 1,
  "partitions": [
    {
      "topic": "first_topic",
      "partition": 20,
      "replicas": [1002, 1001, 1003],
      "log_dirs": ["any", "any", "any"]
    }
  ]
}

The console outputs

Current partition replica assignment

{"version":1,"partitions":[]}

Save this to use as the --reassignment-json-file option during rollback
Error reassigning partition(s):
first_topic-20: The partition does not exist.

Apart from the output {"version":1,"partitions":[]} which doesn't provide much help, the error first_topic-20: The partition does not exist. is reported back to the tool from the server-side, as mentioned earlier. This check could be moved earlier before sending reassignments to server side

Issue Links

• links to: GitHub Pull Request #15659