Status

Current state:  Drafting Implementing

Discussion thread: here

JIRA: CASSANDRA-14395 – C* Management process

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1. PUT /v1/settings: Accepts a JSON object that has keys and values defined as they are in cassandra.yaml. Nested keys have dots in them. This endpoint will update the config option on all or just the local node.
2. GET /v1/settings: Retrieves the current runtime configuration of the provided node id (or all nodes).
3. POST /v1/bulkcmd/<cmd>: Accepts a JSON object that contains the parameter for the given cmd. The cmds will run plugins that execute various actions against one or more nodes.
4. Authentication of the REST API. We expect to support TLS and some type of authorization (e.g. JWT).
   
   

# Set a current runtime configuration on a node
$ curl -i -XPUT 'localhost:5000/v1/settings/' -d '{"compaction_throughput_mb_per_sec": 12}' 
HTTP/1.0 200 OK
Content-Type: application/json
{
  "runtime": {
    "compaction_throughput_mb_per_sec": 12
  }
}
# View the current runtime properties of the node
$ curl -i -XGET 'localhost:5000/v1/settings/'                                          
HTTP/1.0 200 OK
Content-Type: application/json
{
  "runtime": {
    "compaction_throughput_mb_per_sec": 12
  }
}
       
# Increase the compaction_throughput using a bulkcmd instead 
$ curl -i -XPOST 'localhost:5000/v1/bulkcmd/setcompactionthroughput' -d '{"rate_in_mb": 12}'
HTTP/1.0 200 OK
{
  "command": "setcompactionthroughput", 
  "failure": [], 
  "params": {
    "rate_in_mb": 12
  }, 
  "success": [
    "127.0.0.1:7000", 
    "127.0.0.3:7000", 
    "127.0.0.3:7000"
  ]
}

Deferred Scope

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1. POST /v1/settings/?refresh=true: Forces Cassandra to reload supported hot properties it can from the cassandra.yaml configuration file. This allows all source of truth to remain with configuration management. While we think this is the right way to build dynamic configuration (allow configuration management to do it), we think it will require non trivial changes to the daemon.

Code Block

# Refresh the running configuration from cassandra.yaml changes on disk $ curl -i -XPOST 'localhost:5000/v1/settings/?refresh=true' { "cassandra.yaml": { "9e6b2547-bbc1-44cc-bd33-73a12d8e92f4": { "compaction_throughput_mb_per_sec": 12... }, "eff7c7de-c3c4-4d3a-8bd7-7d4dd67b4262": { "compaction_throughput_mb_per_sec": 12... }, "f7965e32-c264-497c-a774-1d04159720a8": { "compaction_throughput_mb_per_sec": 12... } } }

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