hbase-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Ning Li" <ning.li...@gmail.com>
Subject Sequence Number for Cache Flush
Date Tue, 03 Jun 2008 16:25:43 GMT

I want to confirm this before opening an JIRA issue.

An HRegion asks each HStore to flush its cache with a sequence number
X. The assumption is that all the updates before X will be flushed. So
during the startup reconstruction, the updates before X are skipped.

However, the implementation does not guarantee that all the updates
before X will be flushed when HStore flushes with X. This is because
HRegion uses write-ahead logging and X is the latest sequence number.
Some updates may not have been written to the cache which will be

I'll open an JIRA issue once confirmed.


View raw message