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 >>> >
