Broadcast commands in the Cluster client

[uglide]

Motivation

The Cluster client should provide overrides for specific Redis Core and module commands to make them easy to use with OS Cluster API.

• [ ] Provide an abstraction that handles FT.AGGREGATE and executes FT.CURSOR READ or FT.CURSOR DEL on the correct node (on the node where FT.AGGREGATE was executed) automatically
• [ ] Commands that should be executed on primaries with Round-robin load balancing/scheduling
  • [ ] FT.SEARCH
  • [ ] FT.AGGREGATE
  • [ ] TS.MGET
  • [ ] TS.MRANGE
• [ ] Commands that should be broadcasted to all primaries
  • [ ] CONFIG SET
  • [ ] FLUSHALL
  • [ ] FLUSHDB
  • [ ] FUNCTION DELETE
  • [ ] FUNCTION FLUSH
  • [ ] FUNCTION KILL
  • [ ] FUNCTION RESTORE
  • [ ] SCRIPT FLUSH
  • [ ] SCRIPT KILL
  • [ ] SLOWLOG RESET
  • [ ] FT.ALIASADD
  • [ ] FT.ALIASDEL
  • [ ] FT.ALIASUPDATE
  • [ ] FT.ALTER
  • [ ] FT.CREATE
  • [ ] FT.DROPINDEX
• [ ] JSON.MGET:

  
  import { createCluster } from 'redis';

const cluster = createCluster({ rootNodes: [ // ... ] });

cluster.on('error', (err) => console.log('Redis Cluster Error', err));

await cluster.connect();

await cluster.json.set('doc1', '$', { name: 'Alice', age: 32, coins: 100, email: 'alice@nonexist.com' })

await cluster.json.set('doc2', '$', { name: 'Bob', age: 23, coins: 15, email: 'bob@somewhere.gov' })

// Both mget commands should return all documents from cluster console.log(await cluster.json.mGet(['doc1', 'doc2'], '$..name')) console.log(await cluster.json.mGet(['doc2', 'doc1'], '$..name'))

### Basic Code Example

_No response_

[leibale]

https://github.com/redis/node-redis/blob/master/docs/clustering.md#command-routing

[uglide]

@leibale JSON.MGET is a different beast compared to MGET. We don't know the key of documents where the path return us any results. That's why it's helpful to have a high-level wrapper that merges results from all primaries.

[leibale]

Then we need a wrapper like in Graph... executing client.ft.search (or any other command) should be as close as possible to the redis-cli version (with some "type mapping"). "Automagically" running multiple commands when the user executed only one feels wrong.

@chayim @itamarhaber @guyroyse @simonprickett WDUT?

[itamarhaber]

Idk about the implementation, but I'm just saying that where a command should run is a part of the command's docs and modules should use the same API: https://redis.io/docs/reference/command-tips/#request_policy

[leibale]

so something like

const REQUEST_POLICIES = {
  ...
};

const RESPONSE_POLICES = {
  ...
};

// will default to the policy defined in redis
cluster.ping();

// can be overridden
cluster.withPolicy({
  request: ...,
  response: ...
}).ping();