Keith Turner created ACCUMULO-550:
-------------------------------------
Summary: Colocate rfile index entries within file
Key: ACCUMULO-550
URL: https://issues.apache.org/jira/browse/ACCUMULO-550
Project: Accumulo
Issue Type: Improvement
Components: tserver
Reporter: Keith Turner
Assignee: Keith Turner
Fix For: 1.5.0
Before multi-level indexes were introduced, when an an rfile was written its
entire index was held in memory and written out then the file was closed. With
the introduction of multilevel index each index block is written when it fills
up as the file is being written. This was done to handle the case where the
index may not fit into memory. This leads to index blocks being sprinkled
through the file. So any operation that iterates over the entire index can be
slow because it turns into a lot of random accesses.
One possible solution is to buffer lots of index blocks up to some some
threshold and write out alot of index blocks at once. This would make a scan
of the index much faster as it would turn into a set of sequential reads of
large chunks of data.
Could buffer all block at a particular level and write them out when the parent
index block fills up.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators:
https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira
