# "Kernel Queue" for faster Julia (Jupyter) Workflows

**URL:** <https://discourse.julialang.org/t/kernel-queue-for-faster-julia-jupyter-workflows/23972>\
**Category:** Tooling\
**Tags:** jupyter\
**Created:** [May 7, 2019, 4:55pm UTC](https://discourse.julialang.org/t/kernel-queue-for-faster-julia-jupyter-workflows/23972 "2019-05-07T16:55:30Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![tamasgal](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/tamasgal/32/27946_2.png) [@tamasgal](https://discourse.julialang.org/u/tamasgal)\
**Post date:** [May 7, 2019, 4:55pm UTC](https://discourse.julialang.org/t/kernel-queue-for-faster-julia-jupyter-workflows/23972/1 "2019-05-07T16:55:30Z")

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Many Julia users are a bit annoyed by the slow warm-up time. Of course, adapting workflows and getting used to it is not so hard, but to me after a few (not-so-intense) Julia years, it’s still somewhat a annoying. Compared to Python for example it really feels awkwardly slow when you want to quickly do some plots and calculations and I’d really like to stick to Julia.

I think I have an idea and sorry that I don’t directly post a prototype implementation but I currently have a hard time writing up my PhD thesis 🙈

I think we can get around this problem easily by having a – let’s name it – “kernel queue”. What I mean by that is that there is always a Julia process ready to be attached to in your working environment and when you connect to it, it immediately prepares and fires up a new one with a default configuration. This creates a small memory overhead which I’d consider negligible.

This idea might sound a bit dirty, but I think it could even be used to solve a yet another small issue: default template for Jupyter notebooks.  
When I work with Jupyter notebooks (no matter if Python, Julia, Haskell or whatever), I mostly do the same thing, something like:

```python
%matplotlib inline
import matplotlib.pyplt as plt
import numpy as np
import numba as nb
import numexpr as ne

```

or

```julia
using Plots
using StatsBase
using LinearAlgebra
using BenchmarkTools

```

etc.

I’d like to have a button in my Jupyter GUI, where I can load such a default notebook where this is already in the first cell **and** executed in an already available kernel so that I immediately can start to work.  
I know that at least the import part is doable with startup files, but those are not visible in a notebook and implicit imports/mechanism will cause problems when sharing them with others, so I prefer to have them explicitly in a cell… and of course, the kernel needs to be launched first.

For Julia, I would even go further and define an environment with a set of additional “warm-up commands”, like quickly creating and discarding a `histogram()` a `plot()` or whatever, so that those functions are already precompiled. Whatever the users often does (a tiny minimisation procedure to get `Ipopt` with `JuMP` ready etc.)…

I think that a first quick and dirty implementation could be realised with some kind of a kernel hack for Jupyter, but maybe you have a better idea.

What do you think? Do you think that precompilation will soon be ready and satisfyingly fast or is such an experiment worth to implement?

I’ll try to spend a bit of my currently very limited time on Jupyter mechanics and I hope to present a small prototype.

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**Author:** ![pfitzseb](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/pfitzseb/32/45566_2.png) [@pfitzseb](https://discourse.julialang.org/u/pfitzseb)\
**Post date:** [May 7, 2019, 5:36pm UTC](https://discourse.julialang.org/t/kernel-queue-for-faster-julia-jupyter-workflows/23972/2 "2019-05-07T17:36:28Z")

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Juno has had that for a couple of years, and it’s been working (mostly) fine. You’ll have to take some care to not precompile packages from multiple processes at the same time.

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**Author:** ![tamasgal](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/tamasgal/32/27946_2.png) [@tamasgal](https://discourse.julialang.org/u/tamasgal)\
**Post date:** [May 7, 2019, 6:43pm UTC](https://discourse.julialang.org/t/kernel-queue-for-faster-julia-jupyter-workflows/23972/3 "2019-05-07T18:43:45Z")

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Ah ok, I’ll have a look, thanks.