[jira] [Created] (HBASE-8157) Allow better control over lease timeouts on a per-scan basis

["Bryan Beaudreault (JIRA)" <ji...@apache.org>]

Bryan Beaudreault created HBASE-8157:
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             Summary: Allow better control over lease timeouts on a per-scan basis
                 Key: HBASE-8157
                 URL: https://issues.apache.org/jira/browse/HBASE-8157
             Project: HBase
          Issue Type: New Feature
            Reporter: Bryan Beaudreault
            Priority: Minor


Changing the global scanner lease timeout is a heavy-handed solution for long scans on a cluster that may be used by a variety of applications.  Two additions would make this easier to manage in this circumstance:

1) Allow overriding hbase.regionserver.lease.period on a per-scan basis.

2) Allow manual reporting of progress, similar to Hadoop's context.progress().  Example usage:

{noformat}
Scan scan = new Scan(startRow, endRow);
scan.setCaching(someVal); // based on what we expect most rows to take for processing time

ResultScanner scanner = table.getScanner(scan);

for (Result r : scanner) {
  
  // usual processing, the time for which we accounted for in our caching and global lease timeout settings
  
  if (someCondition) {
    // More time-intensive processing necessary on this record, which is hard to account for in the caching

    scanner.progress();

  }
}
{noformat}


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