accumulo-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From joshelser <...@git.apache.org>
Subject [GitHub] accumulo issue #176: Wrote blog post about durability and performance
Date Mon, 31 Oct 2016 13:34:07 GMT
Github user joshelser commented on the issue:

    https://github.com/apache/accumulo/pull/176
  
    > It might be how we create/use the WAL. It's possible that a tserver can create a
WAL and open an output stream to the first block, but never actually write any data to it
(see ACCUMULO-4004). I'm not quite sure of the state of the first block and file from an HDFS
perspective if the node dies while in this state (WAL created, open input stream to the first
block). But, I can say that this does cause a problem (in Accumulo 1.6.4 at least).
    
    Ok, thanks for the details, Dave. If we have a scenario that can reliably reproduce this,
I can likely find an HDFS expert to give us some context on what is happened at the HDFS layer.
I'm not sure how to inspect the state of that block nor would I know what would be "expected"
or "correct" :)
    
    I think expanding on your original suggestion with some context from ACCUMULO-4004 would
be good.


---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at infrastructure@apache.org or file a JIRA ticket
with INFRA.
---

Mime
View raw message