Tutorial by Topics

Hadoop v1 commands: hadoop fs -<command> Hadoop v2 commands: hdfs dfs -<command>

The best complete wiki is available here in github.

To run the example, the command syntax is: bin/hadoop jar hadoop-*-examples.jar wordcount [-m <#maps>] [-r <#reducers>] <in-dir> <out-dir> To copy data into HDFS(from local): bin/hadoop dfs -mkdir <hdfs-dir> //not required in hadoop 0.17.2 and later bin/h...

Parallel collections facilitate parallel programming by hiding low-level parallelization details. This makes taking advantage of multi-core architectures easy. Examples of parallel collections include ParArray, ParVector, mutable.ParHashMap, immutable.ParHashMap, and ParRange. A full list can be f...

Dropwizard pulls together stable, mature libraries from the Java ecosystem into a simple, light-weight package that lets you focus on getting things done. Dropwizard has out-of-the-box support for sophisticated configuration, application metrics, logging, operational tools, and much more, allowin...

Categoricals are a pandas data type, which correspond to categorical variables in statistics: a variable, which can take on only a limited, and usually fixed, number of possible values (categories; levels in R). Examples are gender, social class, blood types, country affiliations, observation time...

func (t T) exampleOne(i int) (n int) { return i } // this function will receive copy of struct func (t *T) exampleTwo(i int) (n int) { return i } // this method will receive pointer to struct and will be able to modify it

template identifier (TemplateParameterList) { ... } struct identifier (TemplateParameterList) { ... } class identifier (TemplateParameterList) { ... } ReturnType identifier (TemplateParameterList)(ParameterList) { ... } identifier!(TemplateInvocationList)

Operators are listed top to bottom, in descending precedence. Operators with the same number have equal precedence and the same associativity. :: The postfix operators: [] () T(...) . -> ++ -- dynamic_cast static_cast reinterpret_cast const_cast typeid The unary prefix operators: ++ -- * ...