Jean-Sébastien Pédron

Feature flags need quality of life improvements

5

### Why Since the introduction of the first required feature flags, it became more painful for users to upgrade if they did not pay attention to the feature flags states....

khepri_machine: Add command deduplication mechanism

3

## Why The "client" side of `khepri_machine` implemented in `process_sync_command/3` have a retry mechanism if `ra:process_command/3` returns an error such as `noproc`, `nodedown` or `shutdown`. However, this retry mechanism can't...

Passing `fun()` to `ra:*_query()` may break when executed on a remote node

5

Passing an anonymous function reference for execution on a remote node may break if the remote node has another version of Erlang or the module hosting the anonymous function. It...

Always pass exported functions to Ra queries

3

## Why Using `fun()` is fragile if it has to be executed on a remote node. Indeed, the remote node may have another version of the module hosting the function...

khepri_machine: Run the query anonymous function from the calling process

4

### Why Before this change, the anonymous function passed to `khepri_machine:fold/5` was executed by the Ra server process. This had two downsides: * it blocked the Ra server to serve...

Add a batch API to push many serial puts/deletes from a single process

1

### Why There are situations where we need to perform a large number of puts, for instance: * `khepri_mnesia_migration` when it copies tables from Mnesia to Khepri. * RabbitMQ when...

### Why In `khepri_mnesia_migration`, we use the ability to switch Mnesia tables to read-only to prevent further updates at the end of a copy from Mnesia to Khepri. It would...

Expensive queries running in the context of the state machine process (the Ra server) will stall following reads and writes. We should: 1. document this, so users know about this...

When we import definitions in RabbitMQ, we perform many `#put{}` in a row. Currently, Khepri's state machine asks Ra to take a snapshot every 4096 commands. With a large definitions...

rabbit_peer_discovery: Fixes and improvements for Consul and etcd

3

## Why ### Node registration After the rework of the peer discovery subsystem in RabbitMQ 3.13.0 to fix cases where clusters would be incorrectly initialized, there were regressions in the...