[ Bug ] Conda Tab Environment Cloning Causes Server Lag

[mlaradji]

Issue

When cloning a conda environment through the "Conda" tab in jupyterhub/jupyterlab, the jupyterhub instance becomes unresponsive. Accessing the jupyterhub instance returns a "504 Gateway Time-out". The downtime usually lasts about 5 minutes on my server. Note also that only the jupyterhub instance is unresponsive; other applications running on the same server (in separate LXD containers) are not affected.

When the server is up again, I can see that the desired environment has been created successfully. The new environment is usable with no issues.

This seems to be a problem with nb_conda: cloning an environment through bash, e.g. using conda create -n test2 --clone test1, does not cause any noticeable server issues.

Set-up

I have jupyterhub installed in a dedicated LXD container on my server computer, which also contains several other concurrently running containers running other server applications.

System Info

Host info

OS: Ubuntu 18.04.1
LXD: 3.5 (snap)

Guest info

OS: Ubuntu 18.04.1
Conda packages:

python 3.6.6 h5001a0f_0 conda-forge
conda 4.5.11 py36_0 conda-forge
conda-env 2.6.0 1 conda-forge
jupyter_client 5.2.3 py_1 conda-forge
jupyter_core 4.4.0 py_0 conda-forge
jupyterhub 0.9.4 py36_0 conda-forge
nb_conda 2.2.1 py36_0 conda-forge
nb_conda_kernels 2.1.1 py36_1 conda-forge