Using user group information for hadoop job submitting. UserGroupInformation ugi = UserGroupInformation.createRemoteUser("hdfs"); try { ugi.doAs(new PrivilegedExceptionAction() { public Void run()... Read More | Share it now!
Month: January 2017
DistributedCache Hadoop
Create a util for adding jar to distributed cache. path: local jar path conf: hadoop conf private static void addJarToDistributedCache( String path, Configuration conf) throws IOException { File jarFile = new... Read More | Share it now!
Hashing issue between guava versions
I was using guava 14 to do String hashing like so: Hashing.sha256().newHasher().putString("String").hash().toString(); => 4d1ca6dce72e20ce214b706168340683bb6b571a7c977c1a9fe029a1cc1c4d06 just upgraded to guava16, calling this... Read More | Share it now!
HashMap遍历的两种方式
第一种: Map map = new HashMap(); Iterator iter = map.entrySet().iterator(); while (iter.hasNext()) { Map.Entry entry = (Map.Entry) iter.next(); Object key = entry.getKey(); Object val = entry.getValue(); }... Read More | Share it now!
uname-Print Linux info
NAME uname — Print operating system name SYNOPSIS uname DESCRIPTION The uname utility writes symbols representing one or more system charac- teristics to the standard output. The following options are... Read More | Share it now!