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  1. MariaDB ColumnStore
  2. MCOL-5058

CMAPI and local smcat runs can access Storage Manager too early causing assertion in SM runtime

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    Details

    • Type: Bug
    • Status: Open (View Workflow)
    • Priority: Major
    • Resolution: Unresolved
    • Affects Version/s: 5.6.5, 6.2.3
    • Fix Version/s: None
    • Component/s: cmapi, Storage Manager
    • Labels:
      None

      Description

      Consider a part of a startup procedure for S3-based installation [1]. CMAPI that gets cluster/start REST call initiates node/start calls at all nodes. node/start in its turn starts with mcs-workernode@1 | mcs-workernode@2. The last two units initiate mcs-loadbrm systemd unit startup that in its turn initiates its local SM running systemctl start mcs-storagemanager. There is a period when SM doesn't fill up its internal structure prefix cache[2] yet when SM bootstraps itself. SM throws an assert exception [3] if SM request[4] comes when prefix cache isn't yet filled up. This failure causes mcs-workernode@

      {1,2}

      units to fail [5]. The most severe issue is that non-primary nodes might look like they are OK but they have a reduced and corrupted extent maps in /dev/shm so that any extent map write operation distributed by the controllernode will set the cluster into read-only.

      Together with Alan we introduced an explicit delays b/w SM and actual extent map image load at the customer's site. However this workaround can't be used as an appropriate long-term solution. IMHO there are two long-term solution options:

      • SM shouldn't assert at this point but return an error so that the above layers, e.g. smcat, CMAPI that calls smcat are notified and retries.
      • CMAPI must wait until primary node workernode is available.

      The second approach doesn't solve the issues with ahead-of-time local smcat runs though so the first one looks more appropriate.

      1. Here I consider systemd startup however the logic is the same for non-systemd container startup.
      2. Prefix cache is the set of dir paths, e.g. data1/systemFiles/dbrm/ that SM owns/processes request for.
      3. Apr 13 16:58:42 nvmesh-target-c env[3222951]: StorageManager: /home/jenkins/workspace/Build-Package/padding_for_CPACK_RPM_BUILD_SOURCE_DIRS_PREFIX_ON_ES_BACKUP_DEBUGSOURCE/storage/columnstore/columnstore/storage-manager/src/Cache.cpp:300: storagemanager::PrefixCache& storagemanager::Cache::getPCache(const boost::filesystem::path&): Assertion `it != prefixCaches.end()' failed.
      Apr 13 16:58:42 nvmesh-target-c systemd[1]: mcs-storagemanager.service: Main process exited, code=killed, status=6/ABRT
      Apr 13 16:58:46 nvmesh-target-c systemd[1]: mcs-storagemanager.service: Failed with result 'signal'.
      4. Local nodes smcat runs or remote-nodes that ask for meta/

      {em, vbbm, vss, journal}

      CMAPI REST endpoints.
      5. Apr 13 16:17:16 nvmesh-target-c workernode[3195838]: SocketPool::getSocket() failed to connect; got 'Connection refused'
      Apr 13 16:17:16 nvmesh-target-c workernode[3195838]: configcpp[3195851]: 16.594847 |0|0|0| E 12 SocketPool::getSocket() failed to connect; got 'Connection refused'
      Apr 13 16:17:16 nvmesh-target-c configcpp[3195851]: 16.594847 |0|0|0| E 12 SocketPool::getSocket() failed to connect; got 'Connection refused'

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            Assignee:
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            Reporter:
            drrtuy Roman
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              Updated:

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