Overview

As you work in RStudio, occasionally you might need to remove an active RStudio session in IDAS. This is useful if, for example, your RStudio session is struggling to load a previous workspace and you get a gray screen. Deleting the active session may allow your RStudio to start from a clean slate and load successfully.

Remove an Active Session in RStudio

1. Log in to IDAS from https://notebooks.hpc.uiowa.edu/.

2. Go to the JupyterLab interface for your IDAS session.

a) If you are using the "Research" instance in IDAS, navigate to the following URL (fill in your HawkID):

https://idas.uiowa.edu/research/user/HAWKID/lab

b) If you are using a class in IDAS,

First, note that the URL of the IDAS tab in your web browser follows the following format - https://notebooks.hpc.uiowa.edu/CLASS-NUMBER/user/HAWKID/rstudio/
Change the end of the URL from rstudio to lab, so that it looks like the following with your class number and your HawkID:

https://notebooks.hpc.uiowa.edu/CLASS-NUMBER/user/HAWKID/lab/

Then press Enter. You will be redirected to a JupyterLab page.

3. Start a Terminal session in IDAS.

Click the Terminal tile under Other in your JupyterLab page::

4. In Terminal, go to the directory where the active R sessions are stored. This directory will change depending on the R version you are using.

a) If you are using R version 3.6:

cd ~/.rstudio/sessions/active

b) If you are using R version 4.0 and later:

5. View the active R sessions:

The output of this command will show you the active sessions. For example, the output below shows the active session's name is session-88cf35c4:

6. Move the active session(s) using the output from the previous step. Note that the name session-88cf35c4 was in the output of the previous step. In this example, we are moving the active session to a folder called backup in the home directory. This will allow us to look back at the active session later if needed.

7. Restart your IDAS session using the steps here:

Research users: Accessing IDAS for Research Use | Restarting your IDAS session
Class users: Accessing IDAS for Class Use | Restarting Your Server on IDAS

8. If this doesn't help, you may need to reset your RStudio's state using the steps here: https://uiowa.atlassian.net/wiki/x/wIaPB.

Preventing Issues

1. Changing R settings

If you have very large objects in your RStudio workspace, RStudio may struggle to load them. In that case, you can change the settings so that your RStudio session starts on a clean slate instead of loading a previous workspace.

If you choose to use this setting, please also consider saving important R objects with the R commands saveRDS() and readRDS(). For more details, see Removing Active Sessions in RStudio | 2. Saving your R objects.

In RStudio, select Tools -> Global Options -> uncheck the box “Restore .RData into workspace at startup”.

For more information about different settings in RStudio, please see this support article from RStudio/Posit: Customizing the RStudio IDE.

2. Saving your R objects

You may want to save certain R objects, especially if those objects took a long time to create with your code. You can selectively save important R objects with the R commands saveRDS() and readRDS().

For more information about saveRDS() and readRDS(), see the R documentation at https://search.r-project.org/R/refmans/base/html/readRDS.html.
For explanations and examples, also see section “D.4.1 Saving R Files” here: D Loading and Saving Data in R | Hands-On Programming with R.

Contact

If you have any questions or comments, please contact research-computing@uiowa.edu.