Alright, thanks for the replies - I'll do some testing. /David
On Sun, Jan 27, 2013 at 11:55 PM, Jean-Marc Spaggiari < [email protected]> wrote: > Hi J-D, > > In your presentation, where are you getting the > hdfsBlocksLocalityIndex value? I'm not able to find it in my UI... > > Thanks, > > JM > > 2013/1/27, Jean-Daniel Cryans <[email protected]>: > > On Sun, Jan 27, 2013 at 2:38 PM, Jean-Marc Spaggiari > > <[email protected]> wrote: > >> Does this have a significant increase on HBase performances? > > > > Ted beats me to linking to my own presentation :P > > > >> And what > >> are the "risks" associated with short-circuit activation (if any)? No > >> risks of corrupting data? > > > > No, nothing, apart. > > > >> > >> Can this be activated after tables are already populated? > > > > Not related at all, this is a region server configuration. > > > >> > >> JM > >> > >> 2013/1/27, Ted <[email protected]>: > >>> For hbase internal checksum, it is not in hbase 0.92.x release. > >>> > >>> Please use 0.94.2 or newer release. > >>> > >>> Thanks > >>> > >>> On Jan 27, 2013, at 2:29 PM, David Koch <[email protected]> wrote: > >>> > >>>> Hello, > >>>> > >>>> I read about "short circuit reads" in the HBase documentation's > >>>> performance > >>>> section[1] and was wondering what people's experiences were using this > >>>> in > >>>> a > >>>> production setting. > >>>> > >>>> Also, > >>>> > >>>> 1. Since only one dedicated user can take advantage of the feature do > >>>> you > >>>> launch all jobs as this user? > >>>> 2. Can dfs.client.read.shortcircuit be set to false for jobs wich are > >>>> not > >>>> launched by the short-circuit user in order to avoid exceptions? In > >>>> other > >>>> words - can this setting be overriden by the client configuration's > >>>> hbase-site.xml? > >>>> 3. In the same context, it is suggested to enable HBase internal > >>>> checksums[2]. Is this a feature which can be enabled in HBase 0.92.1 > >>>> which > >>>> is part of the Cloudera 4.1.x release? > >>>> > >>>> Thank you, > >>>> > >>>> /David > >>>> > >>>> [1] http://hbase.apache.org/book/perf.hdfs.html#ftn.d2145e7370 > >>>> [2] https://issues.apache.org/jira/browse/HBASE-5074 > >>> > > >
