[IMPALA-11022] Impala uses wrong file descriptors for Iceberg tables in local catalog mode

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: Impala 4.1.0
• Component/s: Frontend
• Labels: impala-iceberg
• Epic Color: ghx-label-4
• Assignee: Zoltán Borók-Nagy
• Reporter: Zoltán Borók-Nagy
• Created: 17/Nov/21 10:09
• Updated: 29/Nov/21 17:53
• Resolved: 29/Nov/21 17:53

Description

When local catalog mode is used, Impala retrieves the Iceberg snapshot from CatalogD. The response contains a map of the file descriptors.
https://github.com/apache/impala/blob/b692a92fa2a2277a185fb5823592609b4603c0d8/fe/src/main/java/org/apache/impala/catalog/local/CatalogdMetaProvider.java#L1006

The file descriptors contain block location information, but the hosts are only referred by indexes.
https://github.com/apache/impala/blob/b692a92fa2a2277a185fb5823592609b4603c0d8/common/fbs/CatalogObjects.fbs#L50

In the Coordinator's local catalog the host indexes might refer to different hosts than in CatalogD. We should translate the host indexes to the coordinators host list. Similarly to the LocalFsTable:
https://github.com/apache/impala/blob/b692a92fa2a2277a185fb5823592609b4603c0d8/fe/src/main/java/org/apache/impala/catalog/local/CatalogdMetaProvider.java#L983
https://github.com/apache/impala/blob/b692a92fa2a2277a185fb5823592609b4603c0d8/fe/src/main/java/org/apache/impala/catalog/local/CatalogdMetaProvider.java#L1020-L1024