e2fsck -Nov-) fsck.ext4: Superblock invalid, trying backup blocks... fsck.ext4: Bad magic number in super-block while trying to open /dev/sdb1 使用e2fsck进行修复即可. http://unix.stackexchange.com/questions/33284/recovering-ext4-superblocks…

服务器做mysql时候,添加的新磁盘做lvm时候,创建物理卷报错 saltstack_s:/proc/scsi # cat /proc/partitions major minor #blocks name 8 0 8388608 sda 8 1 204800 sda1 8 2 7658496 sda2 8 3 524288 sda3 8 16 8388608 sdb 8 17 6297448 sdb1 253 0 6297448 dm-0 saltstack_s:/proc/scsi # pv…

android phone when you install the application there will inevitably be "a problem parsing the package" is displayed and you can not successfully install the software. Description of the problem and solutions:1.android system or installed softwa…

Copied From:http://csfieldguide.org.nz/en/curriculum-guides/ncea/level-3/complexity-tractability-TSP.html This is a guide for students attempting Complexity and Tractability in digital technologies achievement standard 3.44. This guide is not officia…

http://c-nergy.be/blog/?p=1777 Step 1 – Boot your Proxmox VE machine. In the boot menu screen, you select your boot option and instead of pressing enter to proceed, you simply press “e” on your keyboard. Click on the picture for better resolution Thi…

本文转自:http://www.pomdp.org/ 一.Background on POMDPs We assume that the reader is familiar with the value iteration algorithm for regular discrete Markov decision processes (MDPs). However, we will need to differentiate these from POMDPs which we could…

网站开发中技术问题的笔记 以下经验基于 MVC 5.2.3 Javascript BUG思考 200 OK真的表示没有问题吗? 有时候Status 200作为WebAPI的返回值,并不表示真的OK,例如取得一个文件,没有取到,但是返回值也会是200. 200只是表示一个WebAPI执行完毕,没有异常而已,并不表示肯定成功. IIS7.0 上传文件失败,返回404. 乍一看是资源无法找到,其实是设定问题,上传文件的最大长度限制,还需要下面这样的配置. maxRequestLength很多文章都提到…

几种范数的解释 l0-Norm, l1-Norm, l2-Norm, - , l-infinity Norm from Rorasa's blog l0-Norm, l1-Norm, l2-Norm, - , l-infinity Norm 13/05/2012rorasa I'm working on things related to norm a lot lately and it is time to talk about it. In this post we are going to…

Common Pitfalls In Machine Learning Projects In a recent presentation, Ben Hamner described the common pitfalls in machine learning projects he and his colleagues have observed during competitions on Kaggle. The talk was titled "Machine Learning Grem…

Beginning OpenMP OpenMP provides a straight-forward interface to write software that can use multiple cores of a computer. Using OpenMP you can write code that uses all of the cores in a multicore computer, and that will run faster as more cores beco…

When a golf player is first learning to play golf, they usually spend most of their time developing a basic swing. Only gradually do they develop other shots, learning to chip, draw and fade the ball, building on and modifying their basic swing. In a…

http://queue.acm.org/detail.cfm?id=1854041 The July/August issue of acmqueue is out now acmqueue is free for ACM professional members. Non-members can purchase an annual subscription for $19.99 or a single issue for $6.99. Download the app from iTune…

My first try was, using partial sort to figure out numbers layer by layer in the heap.. it only failed with TLE with the last test case. The problem is, partial sort cannot guaratee O(n) every time. class Solution { void kth(vector<int> &A, int…

Master作为集群的Manager,对于集群的健壮运行发挥着十分重要的作用.下面,我们一起了解一下Master是听从Client(Leader)的号召,如何管理好Worker的吧. 1.家当(静态属性) 1.设置一个守护单线程的消息发送器, private val forwardMessageThread = ThreadUtils.newDaemonSingleThreadScheduledExecutor("master-forward-message-thread") 2.根据…

新开发的一个app打包报错,度娘谷歌了好久,废了不少时间,发现错误提示已经很明显了,只是自己没读懂而已,先说下问题和解决方法,给同意遇到这个问题的你: Failed to locate or generate matching signing assets: Xcode attempted to locate or generate matching signing assets and failed to do so because of the following issues: No ma…

如果Spark的部署方式选择Standalone,一个采用Master/Slaves的典型架构,那么Master是有SPOF(单点故障,Single Point of Failure).Spark可以选用ZooKeeper来实现HA. ZooKeeper提供了一个Leader Election机制,利用这个机制可以保证虽然集群存在多个Master但是只有一个是Active的,其他的都是Standby,当Active的Master出现故障时,另外的一个Standby Master会被选举出来.由于…

I'm trying to register hostnames in Ambari but getting the error below. We tried to run yum update openssl but its got the latest version. We tried to run yum - update it didn’t help. I also tried removing the other openssl packages openssl-devel-1.0…

LVM:Logical Volume Manager 将多块设备组合成一个来使用 dm:device mapper 设备映射 设备文件 /dev/卷组名/逻辑卷名          /dev/mapper/卷组名-逻辑卷名 物理卷命令命令:pv    pvcreate pvremove psdisplay pvscan pvs pvmove(移动数据)      pvcreate 物理卷 卷组的管理命令:vg    vgcreate  vgscan vgs vgextend(扩充).vgremo…

1 本人刚刚接到一个bug,就是初始化时若设置了datagrid到指定页数,点击下一页显示不对,4 --> ‘4’+1=41的字符串形式,再点击超出页码范围直接到最后一页: 原因:因为 pageNumber接收的是整数型的数据,而你遇到这种bug说明你传入的非整型的数据,需要利用parseInt进行转化一下,就不会再出现这样的错误了: function queryTable(params) { $('#tt').datagrid({ width: $(, height:($(window).he…

出处:http://qosys.info/485/bitbucket-git-prompt-for-password In some cases after adding public ssh keys for your Bitbucket account, Bitbucket could still fail with authentication and as a result it would prompt for your bitbucket password every time yo…

come from https://stackoverflow.com/questions/32245498/sparkexception-master-removed-our-application answer: As mentioned in the attempts, the root cause is a timeout between the master node, and one or more workers. Another thing to try: Verify that…

前言:说明一下,这篇文章对别人应该是没什么用的,单作为自己的记录吧,方便以后查询 电脑重装后没有再使用之前的studio2.3,而是直接下载了最新版的v3.1.2,同时升级了所有SDK(28),NDK(v17),及gradle(4.4)的版本,可以说是洋盘惨了. 随后有一些新版本使用的坑都一一跳过了,什么compile啊,dataBinding啊等等,过了几天发现之前使用jni编译的音视频录制的Muxer的so包用不了,提示的主要是ndk的问题,前篇说到过的问题,ndk的版本其实在v16的版本时…

override def preStart() { logInfo("Starting Spark master at " + masterUrl) webUi.bind() //绑定WEBUI masterWebUiUrl = "http://" + masterPublicAddress + ":" + webUi.boundPort context.system.scheduler.schedule(0 millis, WORKER_TIM…

. Indoor Air pollution 室内空气污染 ① Priscilla Ouchida's "energy-efficient"house turned out to be a horrible dream.When she and her engineer husband married,they built a $100,000,three bedroom home in California.Tightly sealed to prevent air leaks,th…

Today I ran across a situation where I needed to programmatically remove specific elements from a KML file. I was already using Python's ElementTree library for my KML processing, so I attempted to use ElementTree's remove() method. The remove() meth…

Q:When a java class is load by classloader, where the constant poll be put? A:the "Non-Heap Memory". Non-Heap (http://www.yourkit.com/docs/kb/sizes.jsp) Also, the JVM has memory other than the heap, referred to as non-heap memory. It is created…

https://oj.leetcode.com/problems/best-time-to-buy-and-sell-stock-ii/ 代码如下时能AC class Solution { public: int maxProfit(vector<int> &prices) { ; ; i < prices.size() ; ++i) { ]; ) { p += delta; } } return p; } }; 但是,代码如下时却Runtime Error,提示Last exe…

一般情况下,我们启动spark集群都是start-all.sh或者是先启动master(start-master.sh),然后在启动slave节点(start-slaves.sh),其实翻看start-all.sh文件里面的代码,可以发现它里面其实调用的执行的也是start-master.sh和start-slaves.sh文件的内容: 在start-master.sh中定义了CLASS="org.apache.spark.deploy.master.Master" ,最终调用其mai…

This is set in the dfs.datanode.data.dir property, which defaults to file://${hadoop.tmp.dir}/dfs/data (see details here). However, in your case, the problem is that you are not using the full path within HDFS. Instead, do: hadoop fs -ls /usr/local/m…

We decided to ask the Go expert and CTO at QArea’s, Maksim Kuharenko, to share his personal list of must-have Golang sites with news, analytics, cases, and tutorials - so you can receive the information from different experts, form own opinion about…