Thank you for quick response Matt

So you are saying that i will have facilities in Riak 1.3 to handle these
errors in application layer? automatically by riak?

Alex


On Mon, Nov 26, 2012 at 2:09 PM, Matthew Von-Maszewski
<[email protected]>wrote:

> Alex,
>
> The eleveldb backend creates a CRC for every item placed on the disk.  You
> can activate the test of the CRC on every read by adding:
>
>    {verify_checksums, true},
>
> to the "{eleveldb " portion of app.config.  With riak 1.2, you must
> manually monitor each vnode directory for the lost/BLOCKS.bad file changing
> size.  It only increases upon read operations detecting a CRC and/or
> compression corruption error.
>
> Manually monitoring the BLOCKS.bad file is tacky (my apologies).  The
> upcoming 1.3 release will populate riak admin with a counter of errors
> seen.  But that code is still weeks from release.
>
> Matthew
>
> On Nov 26, 2012, at 1:25 PM, Alex Babkin <[email protected]> wrote:
>
> > Hi all
> >
> > first post here, so please be kind :)
> >
> > I have plans to build an experimental riak cluster out of cheap ARM
> computing parts and consumer grade SSDs to measure performance and
> experiment to assess production viability
> > I plan to use levelDB as the backend
> >
> > One thing to be concerned of, in light of various SSD failure stories,
> is of course a scenario of SSD failure and also the way it fails (some
> parts of SSD space just aren't writable anymore, but still readable, i.e
> stuck at some constant value). This may potentially result in a scenario
> where a replicated record on two clusters, one with working SSD and one
> with faulty, will have different data. Will riak try to account for this
> scenario?
> >
> > I'm trying to think of ways to mitigate this risk of nodes failing due
> to these SSD failures or at least get an early indication of a failure
> (however insignificant it may be).
> > Guess my first question should be "Does riak provide any form of
> checksums or what not on the data it reads/writes, or it blindly trusts
> that the backend/filesystem reads/writes data correctly?"
> >
> > If not, are there any other tricks people use to trigger some alarm
> bells that an SSD is 'going' ?
> >
> > Thanks
> > Alex
> >
> >
> >
> >
> >
> > _______________________________________________
> > riak-users mailing list
> > [email protected]
> > http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com
>
>
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