标签：rem ica footer 1.3 user ntb reads org ref
当client请求数据时，datanode会读取数据然后通过TCP协议发送给client.short-circuit绕过了datanode直接读取数据。short-circuit的前提是client和数据在同一个结点上。Here is an example configuration.
<configuration>
<property>
<name>dfs.client.read.shortcircuit</name>
<value>true</value>
</property>
<property>
<name>dfs.domain.socket.path</name>
<value>/var/lib/hadoop-hdfs/dn_socket</value>
</property>
</configuration><configuration>
<property>
<name>dfs.client.read.shortcircuit</name>
<value>true</value>
</property>
<property>
<name>dfs.client.use.legacy.blockreader.local</name>
<value>true</value>
</property>
<property>
<name>dfs.datanode.data.dir.perm</name>
<value>750</value>
</property>
<property>
<name>dfs.block.local-path-access.user</name>
<value>foo,bar</value>
</property>
</configuration>十：HDFS Short-Circuit Local Reads 短路本地读取
标签：rem ica footer 1.3 user ntb reads org ref
原文地址：http://www.cnblogs.com/skyrim/p/7455604.html
