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The following kernel parameters need to be configured when installing the database: fs.aio-max-nr = 1048576 fs.file-max = 6815744 kernel.shmall = 2097152 kernel.shmmax = 4294967295 kernel.shmmni = 4096 kernel.sem = 250 32000 100 128 net.ipv4.ip_local_port_range = 9000 65500 net.core.rmem_default = 262144 net.core.rmem_max = 4194304 net.core.wm ...

Author | Bai Song Objective: In scientific research, it is necessary to analyze the number of vertices involved in each iteration to further optimize the system. For example, in the last line of SSP's compute() method, the current vertex voteToHalt is changed to an InActive state. So after each iteration, all vertices are in the InActive state. ...

[TOC] Tree tree control is indispensable in front-end development, and now most websites display data in tree form. Because it's unfriendly for users to display all the big data. Today we handwritten a Tree plugin ourselves. iview provides controls IView is already mature, if I write the control and iView provides the control who is better, it ...

os module In the os module, there are many methods, some are related to directories, some are related to system files and so on. It encapsulates the API written by C language on linux operating system, such as creating files, creating directory API ...

Posgres-xl is a good thing? Why? Posgres-xl is based on postgresql database. Posgres can hoist many databases. It can do oltp, against mysql, mysql has no analysis function function It can make oltp, counterbalance oracle, oracle ecology is weak, can not be real-time It supports json well and competes with mongodb, which is used by fewer and ...

1.1 Decomposition of data into separate variables list_a = [1,2,3,4,5,6,7,8,9] a,b,c,d,e,f,g,h,i = list_a print(a,b,c,d,e,f,g,h,i) #Receive with an equal number of parameters _,b,c,d,e,f,g,h,_ = list_a print(b,c,d,e,f,g,h) #Do not use a useless variable to receive data   1.2 Decomposition of Elements from Iterative Objects of ...

First, download Spark The first step in using Spark is to download and decompress. Let's start by downloading the precompiled version of Spark. Visits http://spark.apache.org/downloads.html To download the spark installation package. The version used in this article is: spark-2.4.3-bin-hadoop2.7.tgz Second, install Spark cd ~ tar -xf spark ...

Hadoop cluster build-03 compile and install Hadoop Hadoop Cluster Build-02 Installation Configuration Zookeeper Preparations for Hadoop Cluster Building-01 HDFS is a distributed file system used with Hadoop, which is divided into two parts. namenode: nn1.hadoop nn2.hadoop datanode: s1.hadoop s2.hadoop s3.hadoop (If you can't understand th ...

1. Installation instructions1. Environmental description System Version Database Version Framework IP Address patch rhel6.9 11.2.0.4 RAC 192.168.3.2 29698727 rhel6.9 11.2.0.4 RAC 192.168.3.3 29698727 2. The software storage location is planned as follows: Software Storage location Grid /u01/11.2.0/grid Oracle /u01/app/oracle/p ...

Java 8 new features with Example https://www.youtube.com/playlist?list=PLsyeobzWxl7qbvNnJKjYbkTLn2w3eRy1QFirst, you can write method body in the interface When a new method is added to the interface, a method body can be brought along. Benefits: When the new interface is released, the classes that previously implemented the interface need n ...