x=y x_+_y=0 The bit in any position is the modulo-2 sum of all the bits in the corresponding positions of all other disks.…

centos -- how to add a new disk into a mdadm raid5 /dev/md0 which lost a /dev/sdc1 disk and  revoery at another machine? fdisk -l mdadm --stop /dev/md0 # to force active the raid by remaind 3 disks. mdadm -A --force /dev/md0 /dev/sdb1 /dev/sde1 /dev/…

环境:RHEL5.8 RAC 11.2.0.3.0 1:查看ORC和voting disk信息: In 11g Release 2 your voting disk data is automatically backed up in the OCR whenever there is a configuration change. 所以恢复时恢复备份OCR即可,这里和10g是不同的,不需要备份voting disk,备份OCR即可 2:使用cluvfy 工具检查OCR完整性 [grid@rac…

四种会发生Radio Link Failure的场景 -  DL Physical Layer Failure (PDCCH BLER > 10%) -  Random Access Problems (in Connected State) -  Failure after RLC retransmissions(specific PDU) -  Handover Failure - T304 expiry (Acquisition or random access) DL Physical…

PlateSpin克隆复制出的Oracle数据库服务器,往往启动数据库实例都会遇到一些杂七杂八的问题.今天测试DR环境时又遇到了一个特殊场景,在此之前,我已经遇到了下面两起案例: ORA-00600: internal error code, arguments: [kcratr1_lastbwr], [], [], [], [], [], [], [] ORA-00600: internal error code, arguments: [4194] 如下所示,在启动数据库实例时,遇到"ORA…

今天在PlateSpin Forge(关于PlateSpin相关介绍,请见最下面部分简单介绍) 复制出来的一台数据库服务器上,测试数据库能否正常启动时,遇到了"ORA-00600: internal error code, arguments: [kcratr1_lastbwr], [], [], [], [], [], [], []"错误: 在官方文档介绍中,这个错误主要出现在磁盘出现故障导致数据库崩溃后,实例启动失败,并报ORA-00600: arguments: [kcratr1…

ZooKeeper ZooKeeper: A Distributed Coordination Service for Distributed Applications (针对分布式应用的分布式调度服务) Design Goals(设计目标) Data model and the hierarchical namespace(数据模型和命名空间层级) Nodes and ephemeral nodes(节点和临时节点) Conditional updates and watches(条件更新和观…

HDFS Architecture HDFS Architecture(HDFS 架构) Introduction(简介) Assumptions and Goals(假设和目标) Hardware Failure(硬件失效是常态) Streaming Data Access(支持流式访问) Large Data Sets(大数据集) Simple Coherency Model(简单一致性模型) "Moving Computation is Cheaper than Moving Data&q…

本系列文章着重学习和研究OpenStack Swift,包括环境搭建.原理.架构.监控和性能等. (1)OpenStack + 三节点Swift 集群+ HAProxy + UCARP 安装和配置 (2)原理.架构和性能 (3)监控 1. 架构 1.1 总体架构 Swift 的总体架构非常的清晰和独立: # 分层(Tier) 组件(Service) 功能(Function) 特性 部署考量 1 访问层(Access Tier) Load Balancer 硬件(比如F5)或者软件(比如HAPro…

Abstract 想要让应用能够躲过硬件故障是一项非常昂贵的任务,因为这通常意味着对软件进行重构,使它包含复杂的恢复逻辑的同时需要部署专用的硬件,而这些对于提升大型的或者遗留的应用的可靠性是巨大的障碍.我们接下来将描述一个通用的高可用服务,它能够为那些已经存在并且未经修改的软件,在其运行的物理机故障的时候,提供保护.Remus提供了非常强的容错能力,它可以在发生故障的时候,让一个正在运行的系统无缝迁移到另一台物理机上,只需要短暂的停机时间,并且完全保留所有的主机状态,例如网络连接等等.我们采用的…

RAC: Frequently Asked Questions [ID 220970.1]   修改时间 13-JAN-2011     类型 FAQ     状态 PUBLISHED   Applies to: Oracle Server - Enterprise Edition - Version: 9.2.0.1 to 11.2.0.1 - Release: 9.2 to 11.2 Purpose Frequently Asked Questions for Real Applicatio…

>FOR FREEDOM!< {A} Introduction Here's a short description of what is supported in the Linux RAID drivers. RAID is not a guarantee for data integrity, it just allows you to keep your data if a disk dies. The current RAID drivers in Linux support the…

http://www.onjava.com/pub/a/onjava/2001/05/30/optimization.htmlComparing the performance of LinkedLists and ArrayLists (and Vectors) (Page last updated May 2001, Added 2001-06-18, Author Jack Shirazi, Publisher OnJava). Tips: ArrayList is faster than…

In this post, I will distill my own ideas and my own views into a structure for a storage system course. Here, I assume here a 15-weeks course with a single 1 1/2 hour lecture per week (as we have in Germany): Introduction, Overview, Disk Drive Archi…

1 mysql的innodb和cluster的NDB引擎都支持事务,在有共同的特性外,也有不同之处:以mysql cluster NDB 7.3和MySQL 5.6之InnoDB为例:ndb7.3基于mysql5.6,包括支持innodb1.1,因此可以在cluster里使用innodb表,但这些表不是集群的.MySQL Cluster NDB存储引擎用分布式, shared-nothing的架构实现,这使其和innodb有不少不同之处.比如事务.外键.表限制等,具体见下表: Theseare…

常规安装模式: STEP 1 进入bios 将高级设置中,引导模式设置为传统(旧模式)模式,一般存在legacy (旧模式),uefi with csm ,uefi without csm 三个模式,选择legacy 或旧模式. STEP 2 在高级设置里,将设备设置里的设备模式设置成RAID ,并且 将CTRL+I 选项打开. 保存重启系统 STEP 3 开机时同时按ctrl +I 进入 raid 设置界面. STEP 4 进入raid 设置界面之后,可以看到SSD 出于cache 状态.选择…

All transformations in Flink may look like functions (in the functional processing terminology), but are in fact stateful operators. You can make every transformation (map, filter, etc) stateful by using Flink's state interface or checkpointing insta…

121. You want to create a new optimized database for your transactional production environment to be used by a financial application. While creating the database, you want the Oracle software to take care of all basic settings to optimize the databas…

61. View the Exhibit.Which statement regarding the dept and emp tables is true?A) When you delete a row from the emp table, you would receive a constraint violation error.B) When you delete a row from the dept table, you would receive a constraint vi…

HDFS Architecture Introduction The Hadoop Distributed File System (HDFS) is a distributed file system designed to run on commodity hardware. It has many similarities with existing distributed file systems. However, the differences from other distribu…

The Hadoop Distributed File System has been great in providing a cloud-type file system. It is robust (when administered correctly :-)) and highly scalable. However, one of the main drawbacks of HDFS is that each piece of data is replicated in three…

转自于:http://blog.csdn.net/changtao381/article/details/8698935 一.概述: 其结构如下:在src 里, 网络通信:  msg  里面 包括了网络传输的代码, message 目录里定义了 传输的消息格式. 元数据服务器:                   mds  目录 包括了metadata server 的代码 数据服务器:                  os     目录里包含了 object store 的代码      …

Lab 7 Advanced Filesystem Mangement Goal: Develop skills and knowlege related to Software RAID, LVM, quota and backup. Estimated Duration: 120 minutes Sequence 1: Implementing Quotas Deliverable: A user diskhog that cannot use more than 1024k of spac…

马云说:大家还没搞清PC时代的时候,移动互联网来了,还没搞清移动互联网的时候,大数据时代来了. 然而,我看到的是:在PC时代搞PC的,移动互联网时代搞移动互联网的,大数据时代搞大数据的,都是同一伙儿人. 我就是一个做业务方向的,而回忆起真正做技术的时光,也就是大数据时代刚来临的时候做搜索了. 搜索用的是solr框架,solr就是包装了lucene实现了近实时索引.所以源头还是lucene.而且lucene是java写的全文检索库,源码是一定要研究一下的. 刚才提到全文检索,要说它的概念先来谈谈数…

LVM Logical Volume Manager Volume management creates a layer of abstraction over physical storage, allowing you to create logical storage volumes. Logical volumes provide the following advantages over using physical storage directly: Flexible capacit…

易安信笔试题分享:1 protected成员函数能被肿么调用2 “has-a” relationship是指的啥,答案有instance, reference, pointer等...3 int, char, short, long的字节数4 在C++中,变量用时声明是为啥5 命名空间的作用6 int a[10][10];int *b[10];以下哪个正确a[3][4] = 91;b[3][4] = 91;a[1] =NULL;b[1] = a[2];7 12&&10, 12||10, 1…

This is intended to be an easy to understand FAQ on the topic of Kafka. One part is for beginners, one for advanced users and use cases. We hope you find it fruitful. If you are missing a question, please send it to your favorite Cloudera representat…

LVM Logical Volume Manager Volume management creates a layer of abstraction over physical storage, allowing you to create logical storage volumes. Logical volumes provide the following advantages over using physical storage directly: Flexible capacit…

HDFS Architecture HDFS Architecture(HDFS 架构) Introduction(简介) Assumptions and Goals(假设和目标) Hardware Failure(硬件失效是常态) Streaming Data Access(支持流式访问) Large Data Sets(大数据集) Simple Coherency Model(简单一致性模型) “Moving Computation is Cheaper than Moving Data”(…

v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} 范舟琦 范舟琦 2 757 2018-03-12T08:16:00Z 2018-03-12T08:16:00Z 1 1515 8638 71 20 10133 16.00 Clean Clean false fals…