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From Hugh Xedni <>
Subject Re: What happens when tablet is 'lost'?
Date Thu, 09 Aug 2012 13:01:50 GMT

>From your response...
"A tablets persistent data is composed of a set of files in HDFS and a set
of write ahead logs."
"As long as the other tablet server can read the write ahead logs and HDFS
files, no data is lost."

I understand when a write arrives at a TabletServer it is written to a
Write-Ahead Log and then stored in the MemTable until flusing to HDFS via
minor compaction.
1) Are write ahead logs even used when data is bulk inserted into hdfs then
handed to Accumulo?
2) If not, how is data replication achieved when using bulk insert methods?

Thank you,

Hugh Xedni

On Thu, Jul 26, 2012 at 12:31 PM, David Medinets

> Thanks, Keith. That explanation is just what I wanted.

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