Example of integrated development of Spring Boot with Spark and Cassandra systems, sparkcassandra
This article demonstrates how to use Spark as the analysis engine and Cassandra as the data storage, and use Spring Boot to develop the driver.
1. Prerequisites
Install Spark (Spark
[Spark] [Python] Example of a dataframe in which a limited record is taken:SqlContext = Hivecontext (SC)PEOPLEDF = SqlContext.read.json ("People.json")Peopledf.limit (3). Show ()===[Email protected] ~]$ HDFs dfs-cat People.json{"Name": "Alice", "Pcode": "94304"}{"Name": "Brayden", "age": +, "Pcode": "94304"}{"Name": "Carla", "age": +, "Pcoe": "10036"}{"Name": "Diana", "Age": 46}{"Name": "Etienne", "Pcode":
There have also been recent studies using spark streaming for streaming. This article is a simple example of how to do spark streaming programming with the flow-based count of word counts.1. Dependent jar PackagesRefer to the article "Using Eclipse and idea to build the Scala+spark development environment," which speci
probability of B.
Bayesian FormulaBayesian formula provides a method to calculate the posterior probability P (B | A) from the prior probability P (A), P (B), and P (A | B ).
Bayesian theorem is based on the following Bayesian formula:
P (A | B) increases with the growth of P (A) and P (B | A), and decreases with the growth of P (B, that is, if B is more likely to be observed when it is independent of A, then B's support for a is smaller.
Naive Bayes
The naive Bayes algorithm uses Bayesian fo
allowlocal * flag Specifies whether the scheduler can run the computation on the driver rather than * shipping it Out to the cluster, for short actions like first (). */def Runjob[t, U:classtag] (Rdd:rdd[t], func: (Taskcontext, iterator[t]) = = U, Partitions:seq[int] , Allowlocal:boolean, Resulthandler: (Int, U) = = Unit) {if (Stopped.get ()) {throw new illegalstate Exception ("Sparkcontext have been Shutdown")} val callSite = getcallsite val cleanedfunc = Clean (func) loginfo ("Starting job
[Example of a limited record taken in Spark][python]dataframethe continuationIn [4]: Peopledf.select ("Age")OUT[4]: Dataframe[age:bigint]In [5]: Mydf=people.select ("Age")---------------------------------------------------------------------------Nameerror Traceback (most recent)----> 1 Mydf=people.select ("Age")Nameerror:name ' People ' is not definedIn [6]: Mydf=peopledf.select ("Age")In [7]: Mydf.take (3)
To see the next simplest example.
1. Increase in Pom.xml
2. Create a new class
Import static Spark. spark.*;
public class HelloWorld {public static void Main (string[] args) {Get ("/hello", (req, res)-> "Hello World");}}Run HelloWorld directly, visit Http://localhost:4567/hello, and the page will show Hello World
Even Java can write so concise ...
Two.
1. Operator Classification
From the general direction, the Spark operator can be broadly divided into the following two types of transformation: The operation is deferred calculation, that is, the conversion from one RDD to another rdd is not executed immediately, it is necessary to wait until there is an action action to actually trigger the operation. Action: Triggers the Spark submission job (job) and o
Operating EnvironmentCluster Environment: CDH5.3.0The specific jar versions are as follows:Spark version: 1.2.0-cdh5.3.0Hive Version: 0.13.1-cdh5.3.0Hadoop version: 2.5.0-cdh5.3.0Simple Java version of Spark SQL sample
Spark SQL directly queries JSON-formatted data
Custom functions for Spark SQL
Spark
Start by creating a new Maven project in Eclipse Java EE with the following specific optionsClick Finish to create a success, then change the default jdk1.5 to jdk1.8Then edit Pom.xml Join Spark-core DependencyThen copy the source code sample program in the book, because the spark version in the book is 1.2 My environment spark is 2.2.1 so need to modify the code
Operating system: Windows 10Idea:idea 14.1.41: Use idea to import the Spark 1.5 source, note that MAVEN is configured to import automatically2: Check the options for Hadoop, Hive, Hive-thriftserver,yarn in the profiles under the Maven window.3: Check the genertate sourec command under the Maven window4: Change all dependency of the module example to compileReplace Pom.xml First, then the missing one which m
type, which is slightly different from Updatestatebykey. Here is an example /** Mapwithstate.function is the state pair (K,V) of each key to map * Each of the input (Stockmame,stockprice) key value pairs, using the state of each key to map, Returns the new results * Here the state is the last price of each stockname * with the input (Stockname,stockprice) StockPrice the last price in the state ( state.update function) * Mapping res
An official example of this articlehttp://blog.csdn.net/dahunbi/article/details/72821915Official examples have a disadvantage, used for training data directly on the load came in, do not do any processing, some opportunistic.
Load and parse the data file.
Val data = Mlutils.loadlibsvmfile (SC, "Data/mllib/sample_libsvm_data.txt")
In practice, our spark are all architectures on Hadoop systems, and t
The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion;
products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the
content of the page makes you feel confusing, please write us an email, we will handle the problem
within 5 days after receiving your email.
If you find any instances of plagiarism from the community, please send an email to:
info-contact@alibabacloud.com
and provide relevant evidence. A staff member will contact you within 5 working days.