image archive use case: limiting functionalities

CARTAvis / carta-backend

Source code repository for the backend component of CARTA, a new visualization tool designed for the ALMA, the VLA and the SKA pathfinders.

https://cartavis.github.io/

GNU General Public License v3.0

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image archive use case: limiting functionalities #711

Open kswang1029 opened 3 years ago

kswang1029 commented 3 years ago

NOTE: please move this issue to a proper repo if this repo is not the right place

For an image archive such the ALMA science archive, the main use case is to view images quickly instead of performing analysis directly using CARTA as a platform. Thus in this case, the archive would like to limit the CPU usage of some intensive calculations while keeping the performance of image "viewing" functionalities. Non-essential save functions should be disabled too. In these cases, operations include:

cube histogram (multi-threaded)
moment map generation (this is currently single-threaded. no need to limit it. need to revisit this once parallelized)
PV map generation (this will be potentially single-threaded. no need to limit it. need to revisit this if parallelized)
animation playback (multi-threaded)
~~save region~~
~~save image (after moment map generation)~~
~~save subimage (not yet supported as v1.4)~~

veggiesaurus commented 3 years ago

Animation playback is single-threaded.

It wasn't entirely clear to me whether you just wanted to limit the number of threads (this is already possible if you use the OMP_NUM_THREADS environmental variable) or actually disable this functionality entirely (that would be more of a frontend and backend issue)

kswang1029 commented 3 years ago

When animation playback is on, I see my CPU cores are fully occupied. Due to tile generation?

kswang1029 commented 3 years ago

Animation playback is single-threaded.

It wasn't entirely clear to me whether you just wanted to limit the number of threads (this is already possible if you use the OMP_NUM_THREADS environmental variable) or actually disable this functionality entirely (that would be more of a frontend and backend issue)

The idea here is to limit only those not-that-essential tools for the ALMA archive. If we use OMP_NUM_THREADS to globally limit the CPU usage, viewing images will be slowing down too.

veggiesaurus commented 3 years ago

When animation playback is on, I see my CPU cores are fully occupied. Due to tile generation?

yes. So this is true for image viewing in general as well. I guess we could limit the FPS or something?

kswang1029 commented 3 years ago

@kswang1029 to refine the requirements

kswang1029 commented 3 years ago

for the v2.0 release I suggest we handle the write permission only so that the deployment to ALMA archive can use the feature. For advanced computing resource management we need more thoughts.