Details

    • Technical task
    • Resolution: Fixed
    • Minor
    • None
    • Lustre 2.11.0
    • 9223372036854775807

    Description

      The SHORTIO functionality was landed in Lustre 2.11, at the same time as DoM, so these features do not currently work together.

      It may just be a matter of enabling the OBD_CONNECT_SHORTIO feature flag on the MDS connection, but it may be that more work is needed.

      One related possibility is to include DoM file’s dirty data in the close RPC (or conversely a close in the write RPC, whichever makes more sense). That would further reduce the RPC count for small files. Also, since the DoM close will also be updating attributes like atime or mtime/ctime, we may as well write the data at the same time to avoid more disk IO if they are done in separate RPCs.

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            [LU-10289] DoM: add SHORTIO support for MDS RPCs

            Thanks Patrick.

            jgmitter Joseph Gmitter (Inactive) added a comment - Thanks Patrick.

            Resolved in LU-1757.

            paf Patrick Farrell (Inactive) added a comment - Resolved in LU-1757 .

            Agreed, sorry I didn't get it earlier.

            paf Patrick Farrell (Inactive) added a comment - Agreed, sorry I didn't get it earlier.

            https://review.whamcloud.com/#/c/30435/ (LU-1757) landed to master. Is there anything else left for this particular issue? It appears we can close this out as resolved by LU-1757?

            jgmitter Joseph Gmitter (Inactive) added a comment - https://review.whamcloud.com/#/c/30435/ ( LU-1757 ) landed to master. Is there anything else left for this particular issue? It appears we can close this out as resolved by LU-1757 ?

            I actually did this in:
            https://review.whamcloud.com/#/c/30435/

            Which I marked against LU-1757, because we forgot to enable the feature in the OST flags too.

            paf Patrick Farrell (Inactive) added a comment - I actually did this in: https://review.whamcloud.com/#/c/30435/ Which I marked against LU-1757 , because we forgot to enable the feature in the OST flags too.

            Must be, yeah. Uck!

            I also added it to OST_CONNECT_SUPPORTED real quick and still didn't get short i/o yesterday. Not sure why and not sure when I can dig in. I'll try to find time soon.

            paf Patrick Farrell (Inactive) added a comment - Must be, yeah. Uck! I also added it to OST_CONNECT_SUPPORTED real quick and still didn't get short i/o yesterday. Not sure why and not sure when I can dig in. I'll try to find time soon.

            I see OBD_CONNECT_SHORTIO is included in ocd_connect_flags for the OST, but not for the MDT ocd_connect_flags. However, I do NOT see OBD_CONNECT_SHORTIO in OST_CONNECT_SUPPORTED or MDT_CONNECT_SUPPORTED. Maybe you missed to add it to the patch, but it was on the server that you tested against?

            adilger Andreas Dilger added a comment - I see OBD_CONNECT_SHORTIO is included in ocd_connect_flags for the OST, but not for the MDT ocd_connect_flags . However, I do NOT see OBD_CONNECT_SHORTIO in OST_CONNECT_SUPPORTED or MDT_CONNECT_SUPPORTED . Maybe you missed to add it to the patch, but it was on the server that you tested against?

            Mike, does this mean you're going to figure out if short i/o is working on the OST side too? I haven't dug in yet.

            paf Patrick Farrell (Inactive) added a comment - Mike, does this mean you're going to figure out if short i/o is working on the OST side too? I haven't dug in yet.

            Uck. Short i/o doesn't seem to be working at all, even with the flags added. Not sure what changed from when I tested it carefully a while back, but something did on the way to landing, it seems.

            I'll try to find time later to investigate.

            paf Patrick Farrell (Inactive) added a comment - Uck. Short i/o doesn't seem to be working at all, even with the flags added. Not sure what changed from when I tested it carefully a while back, but something did on the way to landing, it seems. I'll try to find time later to investigate.

            Hm. I... I think we didn't add SHORT_IO to the OST connection flags (server, not client side)? I'm confused. I clearly remember manually verifying it was working, by noting the lack of an RDMA.

            Am I wrong? Did we not really enable it? I'll try to test a bit later.

            paf Patrick Farrell (Inactive) added a comment - Hm. I... I think we didn't add SHORT_IO to the OST connection flags (server, not client side)? I'm confused. I clearly remember manually verifying it was working, by noting the lack of an RDMA. Am I wrong? Did we not really enable it? I'll try to test a bit later.

            People

              tappro Mikhail Pershin
              adilger Andreas Dilger
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                Updated:
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