Interactive servers usage best practices¶
CC-IN2P3 provides interactive servers to prepare tasks before they are submitted to he computing platform: development, test, etc. Interactive servers are accessible with the following syntax:
% ssh -Y email@example.com
cca.in2p3.fris an alias that redirects to the least loaded server.
- For Microsoft Windows users we recommend the use of PuTTY as an
As each interactive server is shared by multiple users, we recommend a number of good practices to follow so that your activities can coexist with the other users activities.
Non compliance with these rules may result in some of your processes termination.
- Only one computing process is allowed per interactive server and 3 processes over the entire interactive platform.
- 24 hours CPU time maximum for a process and 1 hour CPU time for a multi-core process.
- Parallel processes with intensive use of both CPU and input/output are not allowed (example:
ninja, etc.) However, it is possible to run such processes as interactive jobs (see interactive jobs).
- Avoid excessive memory consumption that could have an impact on the system. The command
htop -u usernamemay be a useful monitoring tool.
- It is forbidden to run tasks in “batch” mode (eg: processing a large amount of files in loop).
/scratchis not a permanent storage space: data can be deleted at any time to free up space. Under normal circumstances data is deleted after 14 days. Also, avoid large data storage.
- Detached and persistent processes after logout are not allowed (excepted when using Screen).
- Please note that
screenis neither meant as a substitute to the batch system, or as a way to run services nor as a way to hog scarse resources (like GPU interactive computing nodes).
- Processes inactive for more than 24 hours are killed.
- One transfer process is allowed per server (example:
dq2-get) and 3 processes across all interactive servers.
- To preserve user data confidentiality,
rmate(or other similar editor) requires using a random TCP port instead of a fixed port.