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 >>
