box.atomic(function()
  -- your updates...
  box.space.yourspace:update(...)

  -- create task for outer transfer
  box.space.xq:put({task for migration})
end)

fiber.create(function()
  while true do
    fiber.sleep(1) -- collect interval
    
    local pack = {}
    local taken = 0
    repeat
      local task = box.space.xq:take(0)
      if not task then break end
      table.insert(pack, task)
    until #pack >= 100

    -- send pack to others

    for _, task in pairs(pack) do
      box.space.xq:ack(task.id)
    end
  end
end)