[IMPALA-11883] erasure-coded-bytes-read metric doesn't work for Ozone

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: Impala 4.3.0
• Fix Version/s: Impala 4.3.0
• Component/s: Backend
• Epic Color: ghx-label-9
• Assignee: Michael Smith
• Reporter: Michael Smith
• Created: 30/Jan/23 21:32
• Updated: 08/Feb/23 17:25
• Resolved: 08/Feb/23 16:19

Description

The erasure-coded-bytes-read metric only works for HDFS because it relies on the HDFS-specific function hdfsFileGetReadStatistics. We have other ways to track bytes read: by looking at the actual read operations. hdfsFileGetReadStatistics is only needed for tracking things we don't have visibility into such as locality and short-circuit reads.

Update erasure-coded-bytes-read to gather metrics from actual reads similar to what we do for bytes-read. Note that the semantics are different: bytes-read includes reads from memory, local buffer, and cached files; we should omit those as they're not erasure-coded reads.

Issue Links

• relates to: IMPALA-9488 Add EC metrics to impala-server
• relates to: IMPALA-11698 Ozone local reads do not update local-bytes-read