Details

    • New Feature
    • Resolution: Fixed
    • Minor
    • Lustre 2.13.0
    • None
    • 9223372036854775807

    Description

      PCC is a new framework which provides a group of local cache on Lustre client side. No global namespace will be provided by PCC. Each client uses its own SSD as a local cache for it self. Local file system is used on the SSD to manage the data on local caches. Cached I/O is directed to local file system while normal I/O is directed to OSTs.

      PCC uses HSM for data synchronization. It uses HSM copytool to restore file from local caches to Lustre OSTs. Each PCC has a copytool instance running with unique archive number. Any remote access from another Lustre client would trigger the data synchronization. If a client with PCC goes offline, the cached data becomes inaccessible for other client temporally. And after the PCC client reboots and the copytool restarts, the data will be accessible again.

      Following is what will happen in different conditions:

      â–ºWhen file is being created on PCC

      • A normal file is created on MDT;
      • An empty mirror file is created on local cache;
      • The HSM status of the Lustre file will be set to archived and released;
      • The archive number will be set to the proper value.

      â–ºWhen file is being **prefetched* to PCC*

      • An mirror file is copied to local cache;
      • The HSM status of the Lustre file will be set to archived and released;
      • The archive number will be set to the proper value.

      â–ºWhen file is being accessed from PCC

      • Data will be read directly from local cache;
      • Metadata will be read from MDT, except file size;
      • File size will be got from local cache.

      PCC should be able to accelerate some applications with certain I/O patterns.

      For more information, please check the presentation during LUG'18 (http://wiki.lustre.org/images/0/04/LUG2018-Lustre_Persistent_Client_Cache-Xi.pdf).

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            [LU-10092] PCC: Lustre Persistent Client Cache

            All patches targeted for V1 have been landed. Patches being worked on for V2 are moved to LU-12714

            jgmitter Joseph Gmitter (Inactive) added a comment - All patches targeted for V1 have been landed. Patches being worked on for V2 are moved to LU-12714

            Is it ready for testing yet?

            simmonsja James A Simmons added a comment - Is it ready for testing yet?

            Oleg Drokin (green@whamcloud.com) merged in patch https://review.whamcloud.com/35214/
            Subject: LU-10092 First phase of persistent client cache project merging
            Project: fs/lustre-release
            Branch: master
            Current Patch Set:
            Commit: 478f97b212714bc3af9a9a104efab314ca942758

            gerrit Gerrit Updater added a comment - Oleg Drokin (green@whamcloud.com) merged in patch https://review.whamcloud.com/35214/ Subject: LU-10092 First phase of persistent client cache project merging Project: fs/lustre-release Branch: master Current Patch Set: Commit: 478f97b212714bc3af9a9a104efab314ca942758

            Oleg Drokin (green@whamcloud.com) uploaded a new patch: https://review.whamcloud.com/35214
            Subject: LU-10092 First phase of persistent client cache project merging
            Project: fs/lustre-release
            Branch: master
            Current Patch Set: 1
            Commit: 478f97b212714bc3af9a9a104efab314ca942758

            gerrit Gerrit Updater added a comment - Oleg Drokin (green@whamcloud.com) uploaded a new patch: https://review.whamcloud.com/35214 Subject: LU-10092 First phase of persistent client cache project merging Project: fs/lustre-release Branch: master Current Patch Set: 1 Commit: 478f97b212714bc3af9a9a104efab314ca942758

            Oleg Drokin (green@whamcloud.com) merged in patch https://review.whamcloud.com/33844/
            Subject: LU-10092 pcc: change detach behavior and add keep option
            Project: fs/lustre-release
            Branch: pcc
            Current Patch Set:
            Commit: 2dadefb4148f753dd93ee1dbebb3aac49bda2f8d

            gerrit Gerrit Updater added a comment - Oleg Drokin (green@whamcloud.com) merged in patch https://review.whamcloud.com/33844/ Subject: LU-10092 pcc: change detach behavior and add keep option Project: fs/lustre-release Branch: pcc Current Patch Set: Commit: 2dadefb4148f753dd93ee1dbebb3aac49bda2f8d

            Oleg Drokin (green@whamcloud.com) merged in patch https://review.whamcloud.com/33787/
            Subject: LU-10092 pcc: auto attach during open for valid cache
            Project: fs/lustre-release
            Branch: pcc
            Current Patch Set:
            Commit: e29ecb659e51dd67758c5b0adb542210e7aeddb1

            gerrit Gerrit Updater added a comment - Oleg Drokin (green@whamcloud.com) merged in patch https://review.whamcloud.com/33787/ Subject: LU-10092 pcc: auto attach during open for valid cache Project: fs/lustre-release Branch: pcc Current Patch Set: Commit: e29ecb659e51dd67758c5b0adb542210e7aeddb1

            Oleg Drokin (green@whamcloud.com) merged in patch https://review.whamcloud.com/34637/
            Subject: LU-10092 pcc: security and permission for non-root user access
            Project: fs/lustre-release
            Branch: pcc
            Current Patch Set:
            Commit: 2102c86e0d0ae735aed9ee8c1c6a77b63eda6037

            gerrit Gerrit Updater added a comment - Oleg Drokin (green@whamcloud.com) merged in patch https://review.whamcloud.com/34637/ Subject: LU-10092 pcc: security and permission for non-root user access Project: fs/lustre-release Branch: pcc Current Patch Set: Commit: 2102c86e0d0ae735aed9ee8c1c6a77b63eda6037

            Oleg Drokin (green@whamcloud.com) merged in patch https://review.whamcloud.com/32966/
            Subject: LU-10092 pcc: Non-blocking PCC caching
            Project: fs/lustre-release
            Branch: pcc
            Current Patch Set:
            Commit: 58d744e3eaab358ef346e51ff4aa17e9f08efbb3

            gerrit Gerrit Updater added a comment - Oleg Drokin (green@whamcloud.com) merged in patch https://review.whamcloud.com/32966/ Subject: LU-10092 pcc: Non-blocking PCC caching Project: fs/lustre-release Branch: pcc Current Patch Set: Commit: 58d744e3eaab358ef346e51ff4aa17e9f08efbb3

            Oleg Drokin (green@whamcloud.com) merged in patch https://review.whamcloud.com/32963/
            Subject: LU-10092 llite: Add persistent cache on client
            Project: fs/lustre-release
            Branch: pcc
            Current Patch Set:
            Commit: f172b116885753d0f316549a2fb9d451e9b4bd2e

            gerrit Gerrit Updater added a comment - Oleg Drokin (green@whamcloud.com) merged in patch https://review.whamcloud.com/32963/ Subject: LU-10092 llite: Add persistent cache on client Project: fs/lustre-release Branch: pcc Current Patch Set: Commit: f172b116885753d0f316549a2fb9d451e9b4bd2e

            Oleg Drokin (green@whamcloud.com) merged in patch https://review.whamcloud.com/34356/
            Subject: LU-10092 pcc: Reserve a new connection flag for PCC
            Project: fs/lustre-release
            Branch: master
            Current Patch Set:
            Commit: 93aa684046699a1d8802524003115ebaf07758ca

            gerrit Gerrit Updater added a comment - Oleg Drokin (green@whamcloud.com) merged in patch https://review.whamcloud.com/34356/ Subject: LU-10092 pcc: Reserve a new connection flag for PCC Project: fs/lustre-release Branch: master Current Patch Set: Commit: 93aa684046699a1d8802524003115ebaf07758ca

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              lixi_wc Li Xi
              lixi Li Xi (Inactive)
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                Updated:
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