[HBASE-14355] Scan different TimeRange for each column family

• Type: New Feature
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.2.0, 2.0.0
• Component/s: Client, regionserver, Scanners
• Hadoop Flags: Reviewed
• Release Note: Adds being able to Scan each column family with a different time range. Adds new methods setColumnFamilyTimeRange and getColumnFamilyTimeRange to Scan.
• Assignee: churro morales
• Reporter: Dave Latham
• Created: 02/Sep/15 19:48
• Updated: 01/Jul/22 21:09
• Resolved: 17/Feb/16 08:09

Description

At present the Scan API supports only table level time range. We have specific use cases that will benefit from per column family time range. (See background discussion at https://mail-archives.apache.org/mod_mbox/hbase-user/201508.mbox/[e-mail]%3E)

There are a couple of choices that would be good to validate. First - how to update the Scan API to support family and table level updates. One proposal would be to add Scan.setTimeRange(byte family, long minTime, long maxTime), then store it in a Map<byte[], TimeRange>. When executing the scan, if a family has a specified TimeRange, then use it, otherwise fall back to using the table level TimeRange. Clients using the new API against old region servers would not get the families correctly filterd. Old clients sending scans to new region servers would work correctly.

The other question is how to get StoreFileScanner.shouldUseScanner to match up the proper family and time range. It has the Scan available but doesn't currently have available which family it is a part of. One option would be to try to pass down the column family in each constructor path. Another would be to instead alter shouldUseScanner to pass down the specific TimeRange to use (similar to how it currently passes down the columns to use which also appears to be a workaround for not having the family available).

Issue Links

• breaks: HBASE-15283 Revert to IOException in TimeRange constructor to maintain API compat in 1.x line
• is depended upon by: YARN-4455 Support fetching metrics by time range
• is related to: HBASE-14872 Scan different timeRange per column family doesn't percolate down to the memstore
• is related to: HBASE-15067 Rest API should support scan timeRange per column family
• is related to: HBASE-17737 Thrift2 proxy should support scan timeRange per column family