H5Fdisable_mdc_flushes not implemented


#1

Hi,

Looks like H5Fdisable_mdc_flushes is described in the “Fine-Grained Control of Metadata Cache Flushes” RFC but looks like it didn’t end up being implemented.
I see there is a way to H5Odisable_mdc_flushes to do it on each object individually, though that one isn’t available int the Java API, is there plans to add this to the Java API?
Is there an alternative to disable mdc flushes if one is using the Java API?

I noticed there is a H5Pset_mdc_config and there is an evictions_enabled parameter there.

Would setting H5Pset_mdc_config with evictions_enabled = false be equivalent to either H5Fdisable_mdc_flushes or H5Odisable_mdc_flushes?

Thanks,
Mike


#2

Hi @mburkat,

Indeed, it appears that H5Fdisable_mdc_flushes didn’t end up getting implemented, but I looked into H5Odisable/enable_mdc_flushes on the Java side and entered JIRA issue HDFFV-10887 (you will need to register an account on The HDF Group website in order to view the issue) for implementing them. They should be fairly simple to implement so I would expect them to get done soon.


#3

Thanks, I saw the commit in the HDF5 repo and cherry-picked it on top of 1.10.5, and built our lib, seems to be fine. Started to add H5Odisable_mdc_flushes, just wanting to confirm that I don’t need to individually flush each object, I can just do a full H5Fflush to flush the whole mdc cache in one go right?


#4

That should be correct; an H5Fflush on the particular file ID should accomplish what you’re looking for.