[HIVE-21508] ClassCastException when initializing HiveMetaStoreClient on JDK10 or newer

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.3.4, 3.2.0
• Fix Version/s: 2.3.7, 2.4.0, 3.1.3, 3.2.0, 4.0.0-alpha-1
• Component/s: Clients
• Assignee: Ana Jalba
• Reporter: Adar Dembo
• Created: 26/Mar/19 08:49
• Updated: 21/Oct/22 06:56
• Resolved: 23/Sep/19 12:49

Description

There's this block of code in HiveMetaStoreClient:resolveUris (called from the constructor) on master:

  private URI metastoreUris[];
  ...
      if (MetastoreConf.getVar(conf, ConfVars.THRIFT_URI_SELECTION).equalsIgnoreCase("RANDOM")) {
        List uriList = Arrays.asList(metastoreUris);
        Collections.shuffle(uriList);
        metastoreUris = (URI[]) uriList.toArray();
      }

The cast to URI[] throws a ClassCastException beginning with JDK 10, possibly with JDK 9 as well. Note that THRIFT_URI_SELECTION defaults to RANDOM so this should affect anyone who creates a HiveMetaStoreClient. On master this can be overridden with SEQUENTIAL to avoid the broken case; I'm working against 2.3.4 where there's no such workaround.

Here's a StackOverflow post that explains the issue in more detail. Interestingly, the author described the issue in the context of the HMS; not sure why there was no follow up with a Hive bug report.

Issue Links

• Blocked: KUDU-2641 TestHiveMetastoreIntegration fails with JDK9+
• causes: FLINK-28729 flink hive catalog don't support jdk11
• causes: KUDU-2751 Java tests that start an HMS client fail when run on JDK10+
• is duplicated by: HIVE-22190 Class HiveMetaStoreClient fails to instantiate when running on Java 11
• is related to: SPARK-29245 CCE during creating HiveMetaStoreClient