Ulimit -T Under Ubuntu

How do I increase the open files limit for a non-root user?

The ulimit command by default changes the HARD limits, which you (a user) can lower, but cannot raise.

Use the -S option to change the SOFT limit, which can range from 0-{HARD}.

I have actually aliased ulimit to ulimit -S, so it defaults to the soft limits all the time.

alias ulimit='ulimit -S'

As for your issue, you're missing a column in your entries in /etc/security/limits.conf.

There should be FOUR columns, but the first is missing in your example.

* soft nofile 4096
* hard nofile 4096

The first column describes WHO the limit is to apply for. '*' is a wildcard, meaning all users. To raise the limits for root, you have to explicitly enter 'root' instead of '*'.

You also need to edit /etc/pam.d/common-session* and add the following line to the end:

session required pam_limits.so

ulimit different between ubuntu terminal and call from R

Well after a whole lot of tinkering, this ended up being mostly a straightforward R code issue. The ulimit issue may still have been a problem, but actually I need to fix the R code in mapboxapi::tippecanoe(). Because mapboxapi::tippecanoe()uses the system() command to call tippecanoe, not only did I need to change the call to invoke wsl through a login shell using system2("wsl", "- d Ubuntu -lc 'tippecanoe <arguments to tippecanoe>'"), but I also needed to change the paths that R sent to tippecanoe to be linux paths instead of Window paths. If anyone else is having trouble with this, here is the tweaked mapboxapi::tippecanoe() command code that actually worked for me:

tippecanoe2<-function (input, output, layer_name, min_zoom = NULL, 
                       max_zoom = NULL, drop_rate = NULL, overwrite = TRUE, other_options = NULL, 
                       keep_geojson = FALSE) 
{
  
  check_install <- system2("wsl", "tippecanoe -v") == 0
  linux_dir<-paste(getwd(), layer_name, sep="/")#make a directory in your linux directory for the .mbtiles
  parsed<-strsplit(linux_dir, split="/") #parse the windows directory path
  n<-length(parsed[[1]])
  dir_out<-paste("",parsed[[1]][n-1], parsed[[1]][n], sep="/") #construct the linux directory path
  dir.create(linux_dir)
  op<-options(useFancyQuotes = FALSE)
  if (!check_install) {
    rlang::abort(c("tippecanoe is not installed or cannot be found by the application you are using to run mapboxapi.", 
                   "If you haven't installed tippecanoe, please visit https://github.com/mapbox/tippecanoe for installation instructions.", 
                   "If you have installed tippecanoe, run `Sys.getenv('PATH')` and make sure your application can find tippecanoe. If it cannot, adjust your PATH accordingly."))
  }
  opts <- c()
  if (!is.null(min_zoom)) {
    opts <- c(opts, sprintf("-Z%s", min_zoom))
  }
  if (!is.null(max_zoom)) {
    opts <- c(opts, sprintf("-z%s", max_zoom))
  }
  if (is.null(min_zoom) && is.null(max_zoom)) {
    opts <- c(opts, "-zg")
  }
  if (!is.null(drop_rate)) {
    opts <- c(opts, sprintf("-r%s", drop_rate))
  }
  else {
    opts <- c(opts, "-as")
  }
  if (overwrite) {
    opts <- c(opts, "-f")
  }
  collapsed_opts <- paste0(opts, collapse = " ")
  if (!is.null(other_options)) {
    extra_opts <- paste0(other_options, collapse = " ")
    collapsed_opts <- paste(collapsed_opts, extra_opts)
  }
  dir <- linux_dir
  if (any(grepl("^sf", class(input)))) {
    input <- sf::st_transform(input, 4326)
    if (is.null(layer_name)) {
      layer_name <- stringi::stri_rand_strings(1, 6)
    }
    if (keep_geojson) {
      outfile <- paste0(layer_name, ".geojson")
      path <- file.path(dir_out, outfile)
      sf::st_write(input, path, quiet = TRUE, delete_dsn = TRUE, 
                   delete_layer = TRUE)
    }
    else {
      tmp <- tempdir("//wsl$/Ubuntu/tmp")#Here you would need to tweak to the file path for your linux distribution's temporary directory
      tempfile <- paste0(layer_name, ".geojson")
      path <- file.path(tmp, tempfile)
      sf::st_write(input, path, quiet = TRUE, delete_dsn = TRUE, 
                   delete_layer = TRUE)
    }
    call <- sprintf("tippecanoe -o %s/%s %s %s", dir_out, output, 
                    collapsed_opts, path)
    call2<-paste("-d Ubuntu /bin/bash -lc", sQuote(call, op), sep=" ")
      system2("wsl", call2)
  }
  else if (inherits(input, "character")) {
    if (!is.null(layer_name)) {
      collapsed_opts <- paste0(collapsed_opts, " -l ", 
                               layer_name)
    }
    call <- sprintf("tippecanoe -o %s/%s %s %s", dir_out, output, 
                    collapsed_opts, input)
    call2<-paste("-d Ubuntu /bin/bash -lc", sQuote(call, op), sep=" ")
    system2("wsl", call2)
  }
}

Cannot call ubuntu 'ulimit' from python subprocess without using shell option

ulimit is a wrapper around a system call to limit the resources of the current process. Because it acts on the current process, it needs to be called on the current process or it has no effect.

For this reason, the shell implements it as a built-in, so there is no such binary.

If you were to create a shell to just call ulimit, and then kill the shell, you have accomplished nothing, because the process which has the limits is then killed. This is why things like cd that affect the current process need to be implemented like that in the shell.

This means that you cannot call it as a subprocess in python. Fortunately, python has a module to wrap it: https://docs.python.org/3/library/resource.html

How to increase Neo4j's maximum file open limit (ulimit) in Ubuntu?

I am using Debian but this solution should work fine with Ubuntu.

You have to add a line in the neo4j-service script.

Here is what I have done :

nano /etc/init.d/neo4j-service
Add « ulimit –n 40000 » just before the start-stop-daemon line in the do_start section

Note that I am using version 2.0 Enterprise edition.
Hope this will help you.

How do you completely disable limit checking in Linux?

To disable limits (never done before) you can search in PAM modules and comment line:

session  required  pam_limits.so

For set unlimited values you can use command

ulimit -u unlimited

or in /etc/security/limits.conf add lines like:

root soft core unlimited
root hard core unlimited
root soft data unlimited
root hard data unlimited
root soft fsize unlimited
root hard fsize unlimited
...

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