[HIVE-16966] Remove String Checks For Error Handling

• Type: Improvement
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: 3.0.0
• Component/s: Metastore
• Assignee: Unassigned
• Reporter: David Mollitor
• Created: 27/Jun/17 00:06
• Updated: 27/Jun/17 00:06

Description

org.apache.hadoop.hive.metastore.RetryingMetaStoreClient

      } catch (UndeclaredThrowableException e) {
        throw e.getCause();
      } catch (InvocationTargetException e) {
        Throwable t = e.getCause();
        if (t instanceof TApplicationException) {
          TApplicationException tae = (TApplicationException)t;
          switch (tae.getType()) {
          case TApplicationException.UNSUPPORTED_CLIENT_TYPE:
          case TApplicationException.UNKNOWN_METHOD:
          case TApplicationException.WRONG_METHOD_NAME:
          case TApplicationException.INVALID_PROTOCOL:
            throw t;
          default:
            // TODO: most other options are probably unrecoverable... throw?
            caughtException = tae;
          }
        } else if ((t instanceof TProtocolException) || (t instanceof TTransportException)) {
          // TODO: most protocol exceptions are probably unrecoverable... throw?
          caughtException = (TException)t;
        } else if ((t instanceof MetaException) && t.getMessage().matches(
            "(?s).*(JDO[a-zA-Z]*|TProtocol|TTransport)Exception.*") &&
            !t.getMessage().contains("java.sql.SQLIntegrityConstraintViolationException")) {
          caughtException = (MetaException)t;
        } else {
          throw t;
        }
      } catch (MetaException e) {
        if (e.getMessage().matches("(?s).*(IO|TTransport)Exception.*") &&
            !e.getMessage().contains("java.sql.SQLIntegrityConstraintViolationException")) {
          caughtException = e;
        } else {
          throw e;
        }

Using these magic string checks is very fragile. The Metastore should be throwing tailored exceptions instead of relying on string checking in the client code that bubble up from third-party libraries. Metastore should control the underlying libraries and their specific exceptions.

Issue Links

• is related to: HIVE-10384 RetryingMetaStoreClient does not retry wrapped TTransportExceptions