Multiple language server instances on save

[eratio08]

Not sure if this is intended but saving the init.lua file will cause a new instance of sumneko getting started. I assuming that this is not intended as it will slow down vim eventually.

[skovati]

Strange, on my machine it just respawns lua-language-server but never has more than one instance running at a time. Are you getting multiple instances running concurrently? Seems like an easy enough solution would be to remove this source that runs every time we save init.lua.

[gugahoi]

I believe the problem stems from L53

-- Automatically source and re-compile packer whenever you save this init.lua
local packer_group = vim.api.nvim_create_augroup('Packer', { clear = true })
vim.api.nvim_create_autocmd('BufWritePost', {
  command = 'source <afile> | PackerCompile',
  group = packer_group,
  pattern = vim.fn.expand '$MYVIMRC',
})

Removing that line makes it so that only 1 client spawns.

[eratio08]

Strange, on my machine it just respawns lua-language-server but never has more than one instance running at a time. Are you getting multiple instances running concurrently? Seems like an easy enough solution would be to remove this source that runs every time we save init.lua.

Locking at LspInfo I would say there are multiple instances. Saving also uses increasingly more cpu each consequent time

[eratio08]

I believe the problem stems from L53

Yes, I know but getting rid of it will also stop auto-sourcing. The offender is the source <afile> part. I was hoping that there might be a trick to have it lazy init the server.

[VonHeikemen]

I think setting single_file_support = false in the setup function should solve this

[eratio08]

Looks like this prevents the multiple start ups, thx @VonHeikemen!

[eratio08]

Fix for another config was to comment out workspace = { library = vim.api.nvim_get_runtime_file('', true) }, before that it would be very slowly starting server and it was starting always 2 server at the same time.

[anthony-S93]

@eratio08

I myself stumbled upon this issue today. Turning off single file support does prevent multiple instances of sumneko_lua from being attached to the file after the sourcing in the auto-command; however, what if we need single_file_support?

To solve this problem, I wrote a few lines of code that sort of wrap around your require('lspconfig').sumneko_lua.setup{} logic.

Note that this assumes you are calling the setup{} function in the same file containing the auto-command. For me, that's inside the plugins.lua file:

vim.cmd([[
      augroup packer_user_config
          autocmd!
          autocmd BufWritePost plugins.lua source <afile> | PackerCompile
      augroup end
  ]])

...Your other config...

--Setting up language servers
local lspconfig = require("lspconfig")
local start_sumneko_lua = true --boolean defaults to true, otherwise, the server will never start
local current_buf_id = vim.api.nvim_get_current_buf()
local servers_attached_to_current_buf = vim.lsp.get_active_clients({bufnr = current_buf_id})

for _, server in ipairs(servers_attached_to_current_buf) do
    if server.name == "sumneko_lua" then --an instance of sumneko_lua is already attached to the buffer
        start_sumneko_lua = false 
    end
end

--After that, all you have to do is to wrap sumneko lua's setup() call inside a conditional using the boolean

if start_sumneko_lua then
    lspconfig.sumneko_lua.setup{
         -- yada yada yada
    }
end

--Other servers don't need this, so their setup can be called as usual
lspconfig.pyright.setup{

}

--yada yada yada...

The idea is simply to use some kind of "flag" to determine whether or not to call the setup() function for sumneko_lua (since the setup function determines the availability of the language server). The flag defaults to true but will be switched to false if the current buffer already has an instance of sumneko_lua attached to it.

Granted, the code is a bit inelegant and 'hackish', but it worked without any issues for me because all my plugin configuration is inside packer.nvim's plugin specification file (plugins.lua).

I hope this helps.

[VonHeikemen]

Problem happens when you source the file more than once. I would just put all the language servers inside an if that checks the value of a global variable.

if vim.g.user_lsp_setup == nil then
  vim.g.user_lsp_setup = true

  require('lspconfig').sumneko_lua.setup({
    on_attach = on_attach,
    capabilities = capabilities,
    --- more code.....
  })

  require('lspconfig').tsserver.setup({
    on_attach = on_attach,
    capabilities = capabilities,
  })
end