Potential incompatibility with ruby memcached client

[ashotland]

Using dali client set commands times out

To Reproduce
Steps to reproduce the behavior:
install ruby and dali
sudo apt update
sudo apt install ruby-full
sudo gem install dalli

create test.rb with the following content

require 'dalli'

begin
  # Create Memcached client with minimal configuration
  memcached = Dalli::Client.new('localhost:11211', {
    socket_timeout: 30,  # Increased timeout
    compress: false,     # Disable compression
    serializer: nil      # Disable serialization to match telnet behavior
  })

  puts "Testing connection..."

  # Try the same operation that worked in telnet
  result = memcached.set('my_key', 'hello', 900)
  puts "Set result: #{result}"

  value = memcached.get('my_key')
  puts "Retrieved value: #{value}"

rescue => e
  puts "Error: #{e.class} - #{e.message}"
  puts e.backtrace
end

Run dragonfly
docker run --pull always --network=host --ulimit memlock=-1 docker.dragonflydb.io/dragonflydb/dragonfly:latest --memcached_port 11211

Run ruby script
ruby test.rb

Expected behavior
Expect script to print response but it times out instead

The following script succeeds

[romange]

Probably same like #3071

we do not support memcache binary protocol

[ashotland]

Trying with protocol: 'meta' only options are binary or meta

require 'dalli'

begin
  # Create Memcached client with minimal configuration
  memcached = Dalli::Client.new('localhost:11211', {
    socket_timeout: 30,  # Increased timeout
    compress: false,     # Disable compression
    protocol: 'meta'
  })

  puts "Testing connection..."

  # Try the same operation that worked in telnet
  result = memcached.set('my_key', 'hello', 900)
  puts "Set result: #{result}"

  value = memcached.get('my_key')
  puts "Retrieved value: #{value}"

rescue => e
  puts "Error: #{e.class} - #{e.message}"
  puts e.backtrace
end

getting

ruby test.rb 
Testing connection...
Error: Dalli::DalliError - Response error: ERROR
/var/lib/gems/3.0.0/gems/dalli-3.2.8/lib/dalli/protocol/meta/response_processor.rb:170:in `error_on_unexpected!'
/var/lib/gems/3.0.0/gems/dalli-3.2.8/lib/dalli/protocol/meta/response_processor.rb:54:in `meta_set_with_cas'
/var/lib/gems/3.0.0/gems/dalli-3.2.8/lib/dalli/protocol/meta.rb:66:in `set'
/var/lib/gems/3.0.0/gems/dalli-3.2.8/lib/dalli/protocol/base.rb:36:in `request'
/var/lib/gems/3.0.0/gems/dalli-3.2.8/lib/dalli/options.rb:18:in `block in request'
/var/lib/gems/3.0.0/gems/dalli-3.2.8/lib/dalli/options.rb:17:in `synchronize'
/var/lib/gems/3.0.0/gems/dalli-3.2.8/lib/dalli/options.rb:17:in `request'
/var/lib/gems/3.0.0/gems/dalli-3.2.8/lib/dalli/client.rb:426:in `perform'
/var/lib/gems/3.0.0/gems/dalli-3.2.8/lib/dalli/client.rb:208:in `set_cas'
/var/lib/gems/3.0.0/gems/dalli-3.2.8/lib/dalli/client.rb:201:in `set'
test.rb:14:in `<main>'

[romange]

yeah, we do not support both meta nor binary.