After starting spark shell, query the table information in hive and report an error
spark.sql("select * from student.student ").show()
Caused by: java.lang.RuntimeException: Unable to instantiate org.apache.hadoop.hive.ql.metadata.SessionHiveMetaStoreClient
at org.apache.hadoop.hive.metastore.MetaStor ...
Posted on Wed, 06 Nov 2019 08:12:21 -0800 by Jagarm
1. What is flume
1) Flume provides a distributed and reliable service for efficient collection, aggregation and movement of logs with large amount of data. Flume can only run in Linux environment.2) Flume is based on flow architecture, with strong fault tolerance, flexibility and simplicity.3) Flume and Kafka are used for real-time ...
Posted on Tue, 05 Nov 2019 10:15:32 -0800 by menriquez
OS version: RT thread 4.0.0
RT thread's serial driver framework is familiar with Linux, which is divided into I/O device framework + device bottom driver;
1. Initialization and use of serial device
Register the enabled UART obj  with the device
rtthread_startup --> rt_hw_usart_init() --> rt_hw_serial_register --> ...
Posted on Tue, 05 Nov 2019 07:20:53 -0800 by rcatal02
When we do marketing activities or promotion, it's easy to encounter links blocked by wechat, leading to a prompt "stop visiting this page" in wechat, so we can't download apps and other situations. At this time, we need to download the app function directly from wechat. Many users don't know about this implementation. Let's explain ...
Posted on Sun, 03 Nov 2019 15:09:17 -0800 by smilley654
I. hdfs namenode HA
In Hadoop 1.0, there is a single point of failure of the namenode in the hdfs cluster. When the namenode is unavailable, the whole hdfs cluster service will be unavailable. In addition, if you need to temporarily design or operate the namenode, after you stop the namenode, the hdfs cluster cannot be used.Through ...
Posted on Sat, 02 Nov 2019 16:24:43 -0700 by newbie8899
Code download address: https://github.com/tazhigang/big-data-github.git
I. demand: output statistical results to different files (zones) according to different provinces where mobile phones belong
II. Data preparation
Data preparation: phoneData.txt in case 2
According to the first three digits of the phone number
III. create maven project
Posted on Fri, 01 Nov 2019 16:50:43 -0700 by biz0r
1 program main entrance
The main function returns the JLI? Launch() function, located at
2 java.c # JLI_Launch()
JavaMain() is a native call to a Java main program.
In this method, the initialization of the virtual machine will be performed, the main class and ...
Posted on Wed, 30 Oct 2019 13:12:49 -0700 by jonnypixel
I. Basic overview of serialization
1. What is serialization
Serialization is the conversion of objects in memory into byte sequences (or according to other data transfer protocols), so as to facilitate persistent storage to disk and network transmission.
2. Why serialization is needed
Generally, objects are only stored in local memory, and onl ...
Posted on Mon, 28 Oct 2019 22:13:00 -0700 by magic-eyes
3. Business core code
4. Program life
Recently, in the development of big data, there are questions about the competition between threads and the order of execution in JAVA. Therefore, learn the advanced writing method of concurrent programm ...
Posted on Sun, 27 Oct 2019 21:31:48 -0700 by Jakehh
Using LinqDB to query Sqlite database data, whether it is big data or a small amount of data, feels particularly time-consuming, especially the first query
A data table with 27000 pieces of data
Query 27000 pieces of data, taking 1s
It also takes 750ms to query 8 pieces of data
It takes 475ms to query 2700 ...
Posted on Fri, 25 Oct 2019 05:46:05 -0700 by Digitry Designs