neovim/runtime/lua/vim/lsp/health.lua

local M = {}

--- Performs a healthcheck for LSP
function M.check()
  local report_info = vim.fn['health#report_info']
  local report_warn = vim.fn['health#report_warn']

  local log = require('vim.lsp.log')
  local current_log_level = log.get_level()
  local log_level_string = log.levels[current_log_level]
  report_info(string.format("LSP log level : %s", log_level_string))

  if current_log_level < log.levels.WARN then
    report_warn(string.format("Log level %s will cause degraded performance and high disk usage", log_level_string))
  end

  local log_path = vim.lsp.get_log_path()
  report_info(string.format("Log path: %s", log_path))

  local log_size = vim.loop.fs_stat(log_path).size

  local report_fn = (log_size / 1000000 > 100 and report_warn or report_info)
  report_fn(string.format("Log size: %d KB", log_size / 1000 ))
end

return M