Tag: blog http OS file 2014 Art
Preface:
Spark has been very popular recently. This article does not talk about spark principles, but studies how to compile spark cluster construction and service scripts. We hope to understand spark clusters from the perspective of running scripts.
mode:stringtruestringtruestringtruedatestringtruestringtrue)3. Dataframe Method Combat(1) Explicit first two rows of datascala> df.show(2)+----------------+--------------------+--------------------+--------------------+--------------------+| author| author_email| commit| date| message|+----------------+--------------------+--------------------+--------------------+--------------------+| Jos
Step 2: Use the spark cache mechanism to observe the Efficiency Improvement
Based on the above content, we are executing the following statement:
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,2000 reducers,20+ job , taking 16 hours. Porting directly to spark requires 6 engineers for 3 quarters of work. Yahoo's approach is to build a transition layer that automatically translates Hadoop streaming jobs into spark jobs in just 2 quarters. The next step is to analyze performance and optimize it.
The start of the spar
Step 2: Use the spark cache mechanism to observe the Efficiency Improvement
Based on the above content, we are executing the following statement:
It is found that the same calculation result is 15.
In this case, go to the Web console:
The console clearly shows that we performed the "count" Operation twice.
Now we will execute the "Sparks" variable for the "cache" Operation:
Run the Count operation to view the Web console:
At this tim
Step 2: Use the spark cache mechanism to observe the Efficiency Improvement
Based on the above content, we are executing the following statement:
It is found that the same calculation result is 15.
In this case, go to the Web console:
The console clearly shows that we performed the "count" Operation twice.
Now we will execute the "Sparks" variable for the "cache" Operation:
Run the Count operation to view the Web console:
At this time, we found
, and here I am C:\Hadoop\hadoop-2.7.1\bin.In the open cmd, enterC:\Hadoop\hadoop-2.7.1\bin\winutils.exe chmod 777/tmp/hive //Modify permissions, 777 is get all permissionsBut we found that we reported some other mistakes (this error will also occur in Linux)1 The reason for this is that there is no permission to write metastore_db this file in Spark.How to handle: We grant 777 permissionLinux Environment , we operate under root:1 sudo chmod 777/home/hadoop/spark2
Create a tableSchemaWrite DataMetaStoreThe other thing is to create a subdirectory under the warehouse directory named after the table name.
CREATE TABLE u_data ( userid INT, movieid INT, rating INT, unixtime STRING)ROW FORMAT DELIMITEDFIELDS TERMINATED BY ‘\t‘STORED AS TEXTFILE;Step 4: import data
The imported data is stored in the table directory created in step 3.
LOAD DATA LOCAL INPATH ‘/u.data‘OVERWRITE INTO TABLE u_data;Step 5: Query
SELECT
the driver randomly to a machine, which is suitable for the stable operation after the Operation debugging.-ExecutorDiscard –total-executor-cores in standalone mode instead of –num-executors 3, task execution directory
spark2.0.1 client in hadoop001/opt/spark2, in order to smooth migration, the original spark1.5.2 of the client path is unchanged, we suggest that the new requirements on the yarn above.
4, the Job History record inquiry
The
algorithm, run on Hadoop, can be expressed in Scala, run on Spark, and have a multiple increase in speed. In contrast, switching between MPI and Hadoop algorithms is much more difficult.
(2) Functional programmingSpark is written by Scala, and the supported language is Scala. One reason is that Scala supports functional programming. This has created the Spark code concise, and secondly makes the process ba
Liaoliang Teacher's course: The 2016 big Data spark "mushroom cloud" action spark streaming consumption flume collected Kafka data DIRECTF way job.First, the basic backgroundSpark-streaming get Kafka data in two ways receiver and direct way, this article describes the way of direct. The specific process is this:1, direct mode is directly connected to the Kafka node to obtain data.2. Direct-based approach: P
Because Spark is implemented in Scala, spark natively supports the Scala API. In addition, Java and Python APIs are supported.For example, the Python API for the Spark 1.3 version. Its module-level relationships, for example, are as seen in:As you know, Pyspark is the top-level package for the Python API, which includes several important subpackages. Of1) Pyspark
Contents of this issue: 1. Spark Streaming job architecture and operating mechanism2. Spark Streaming fault tolerant architecture and operating mechanism In fact, time does not exist, it is by the sense of the human senses the existence of time, is a kind of illusory existence, at any time things in the universe has been happening.Spark streaming is like time, always following its running mechanism and ar
= Sc.textfile (". /readme.md ", 2)2) Enter val words = lines.flatmap (line = Line.split (""))3) input val ones = words.map (W = (W, 1))4) Enter val counts = Ones.reducebykey (_ + _)5) Input Counts.foreach (println)3. Anatomy Spark-shellCheck out what Spark-shell did by using Word count to perform the process in
locally. Recently, Spark has just released version 1.2.0. We will use this version to complete the code presentation for the sample app.How to Run SparkWhen you install spark on your local machine or use a cloud-based spark, there are several different ways to connect to the spark engine.The following table shows the
of DAG graphOnly the action action triggers the execution of the job, documenting the execution flow of each job, forming lineage and dividing the stage, etc.(3) Use Akka as event-driven to dispatch tasks with little overhead(4) Full stack supportDefects:(1) Higher machine configuration requirements than map-reduce(2) Sacrificing hardware to improve performance3. What can spark bring?(1) Full stack multi-c
.jar --class org.apache.spark.examples.SparkPi --args yarn-standalone --num-workers 3 --master-memory 4g --worker-memory 2g --worker-cores 1
The output log shows that when the client submits the request, am specifiesOrg. Apache. Spark. Deploy. yarn. applicationmaster
13/12/29 23:33:25 INFO Client: Command for starting the Spark
Label: style blog http OS Using Ar Java file sp Download the downloaded"Hadoop-2.2.0.tar.gz "Copy to"/Usr/local/hadoop/"directory and decompress it: Modify the system configuration file ~ /Configure "hadoop_home" in the bashrc file and add the bin folder under "hadoop_home" to the path. After modification, run the source command to make the configuration take effect. Next, create a folder in the hadoop directory using the following command: Next, modify the hadoop configuration file. F
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