2022-07-13 Meeting notes

lockless Reads status update

@Thomas, Jyothish (STFC,RAL,SC)

Open

metadata detail

Open

sampled OSD operations from WNs

Last Friday latest version rolled out to WNs. No more locks; remaining sets of metadata ops taking a greater proportion of original metadata time. Fewer unlocks overall, but seem to be slower?

To follow up on the unlocks; source of the slow unlocks. How to reduce the unlock operations.

For unlocks: still looking into the completion objects.

5.4.3 releases in Centos 7 / EL8;

• Problems observed: (pgRead / pgWrites)

All

https://stfc.atlassian.net/browse/XRD-14 , https://stfc.atlassian.net/browse/XRD-10

5.4.0 enabled by default pgRead and pgWrite on clients. Significant speed reduction. (due to 64kib r/w size).
Affects XRoot protocol transfers (e.g. via xrdcp).

Disabling pgRW requires modifying the XRD_PGProtocolversion (a hard-coded #define), so that the client falls back to a standard Read/Write.

Test against the bufferedIO version also needed.

Tom indicates

Deletions Status

@Ian Johnson , all

Update on deletions test

To look at 5,10,100GB deletes

Other thoughts on unified xrootd instances and possible changes to ceph.conf ops

Deletions Strategy

all

Postponed