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
_______________________________________________
riak-users mailing list
[email protected]
http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com
