[IMPALA-7615] Partition metadata mismatch should be handled gracefully in local catalog mode.

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: Impala 3.1.0
• Component/s: Frontend
• Labels: catalog-v2
• Epic Color: ghx-label-7
• Assignee: Bharath Vissapragada
• Reporter: Bharath Vissapragada
• Created: 24/Sep/18 23:38
• Updated: 14/May/20 07:54

Description

This is a Catalog v2 only improvement

An RPC to fetch partition metadata for a partition ID that does not exist on the Catalog server currently throws IAE.

@Override
  public TGetPartialCatalogObjectResponse getPartialInfo(
      TGetPartialCatalogObjectRequest req) throws TableLoadingException {
      for (long partId : partIds) {
        HdfsPartition part = partitionMap_.get(partId);
        Preconditions.checkArgument(part != null, "Partition id %s does not exist",  <------
            partId);
        TPartialPartitionInfo partInfo = new TPartialPartitionInfo(partId);

        if (req.table_info_selector.want_partition_names) {
          partInfo.setName(part.getPartitionName());
        }

        if (req.table_info_selector.want_partition_metadata) {
          partInfo.hms_partition = part.toHmsPartition();

This is undesirable since such exceptions are not transparently retried in the frontend. Instead we should fix this code path to throw InconsistentMetadataException, similar to what we do for other code paths that handle such inconsistent metadata like version changes.

An example stack trace that hits this issue looks like follows,

org.apache.impala.catalog.local.LocalCatalogException: Could not load partitions for table partition_level_tests.store_sales
at org.apache.impala.catalog.local.LocalFsTable.loadPartitions(LocalFsTable.java:399)
at org.apache.impala.catalog.FeCatalogUtils.loadAllPartitions(FeCatalogUtils.java:207)
at org.apache.impala.catalog.local.LocalFsTable.getMajorityFormat(LocalFsTable.java:244)
at org.apache.impala.planner.HdfsTableSink.computeResourceProfile(HdfsTableSink.java:75)
at org.apache.impala.planner.PlanFragment.computeResourceProfile(PlanFragment.java:233)
at org.apache.impala.planner.Planner.computeResourceReqs(Planner.java:365)
at org.apache.impala.service.Frontend.createExecRequest(Frontend.java:1020)
at org.apache.impala.service.Frontend.doCreateExecRequest(Frontend.java:1162)
at org.apache.impala.service.Frontend.createExecRequest(Frontend.java:1077)
at org.apache.impala.service.JniFrontend.createExecRequest(JniFrontend.java:156)
Caused by: org.apache.thrift.TException: TGetPartialCatalogObjectResponse(status:TStatus(status_code:GENERAL, error_msgs:[IllegalArgumentException: Partition id 10084 does not exist]), lookup_status:OK)
at org.apache.impala.catalog.local.CatalogdMetaProvider.sendRequest(CatalogdMetaProvider.java:322)
at org.apache.impala.catalog.local.CatalogdMetaProvider.loadPartitionsFromCatalogd(CatalogdMetaProvider.java:644)
at org.apache.impala.catalog.local.CatalogdMetaProvider.loadPartitionsByRefs(CatalogdMetaProvider.java:610)
at org.apache.impala.catalog.local.LocalFsTable.loadPartitions(LocalFsTable.java:395)
... 9 more

Issue Links

• relates to: IMPALA-7127 Fetch-on-demand metadata for the impalad-side catalog