Cloud Technology

First, eigenvalue decomposition 1, matrix multiplication before introducing the geometrical meaning of eigenvalue and eigenvector, the geometric meaning of matrix multiplication is introduced. Matrix multiplication corresponds to a transformation, a new vector that transforms any vector into another direction or length. In this process, the original vector mainly occurs in rotation and expansion of the change. If the matrix only has a scaling transformation for some vectors and does not produce a rotational effect, then these vectors are called the eigenvector of the matrix, and the scale of the scaling is the characteristic value. For example:, its corresponding linear transformation is the following form: Because the matrix M is symmetrical ...

Overview The key information maintained by the control plane is the network state. The control plane must aggregate this information and make it available to the application. In addition, in order to maintain scalability and component reuse, applications should be exempt from protocol details, even though network state information is obtained through a specific protocol. The Onos topology of the protocol is implemented by two complementary mechanisms: Network Discovery and configuration. The former uses the network protocol to let Onos identify the location and/or performance of the network elements, and take the initiative to carry out the relevant collection work when the function is enabled. The latter allows applications and operations ...

HDFS block lost too much access to Safe Mode solution background and description of the phenomenon (Background and symptom) due to insufficient disk space, low memory, system power loss and other reasons caused Datanode DataBlock lost, Similar logs appear as follows: The number of live Datanodes 3 super-delegates reached the minimum number 0. Safe mod ...

Last article we said memcached to achieve high availability and prevent a single point of failure can be implemented through magent, next we configure a highly available cluster magent proxy server: 192.168.200.101 memcached node: ( Can be on the same server to open three memcached node to see the previous introduction, can also be one server one memcached:192.168.200.100 11000 port memcached:192.168.2 ...

Hive on Mapreduce Hive on Mapreduce execution Process Execution process detailed parsing step 1:ui (user interface) invokes ExecuteQuery interface, sending HQL query to Driver step 2:driver Create a session handle for the query statement and send the query statement to Compiler for statement resolution and build execution Plan step 3 and 4:compil ...

1. Node Preparation 192.168.137.129 spslave2 192.168.137.130 spmaster 192.168.137.131 spslave1 2. Modify host name 3. Configure password-free login first to the user's home directory (CD ~), ls view the file, one of which is ". SSH", which is the file price that holds the key. The key we generate will be placed in this folder later. Now execute command generation key: Ssh-keygen-t ...

1, Cluster strategy analysis: I have only 3 computers, two ASUS notebook i7, i3 processor, a desktop PENTIUM4 processor. To better test zookeeper capabilities, we need 6 Ubuntu (Ubuntu 14.04.3 LTS) hosts in total. The following is my host distribution policy: i7: Open 4 Ubuntu virtual machines are virtual machine name memory hard disk network connection Master 1G 20G bridge master2 1G 20G ...

Jenkins installation is very simple: 1. Download Jenkins.war either Liunx or Windows can, because it is Java developed. As long as you have a Web server and JDK, you can install and run. 2. Download Address: Http://mirrors.jenkins.io/war/latest/jenkins.war 3. Place the downloaded Jenkins.war in the WebApps directory of the Tomcat server; 4. Install basic finish, restart t ...

Memcached+magent+keepalived high Availability cluster two. We have already configured the memcached+magent below if the magent is down, it is not possible to continue to provide services, so we used keepalived to add a standby magent proxy server. When a magent is down, it is replaced by another. Configuration steps: Two magent proxy Server, a set of one to do from, when the main downtime from the successor to continue to work. Two Magen ...

When the architect started assigning me such a task, I thought it was nested inside Docker to create Docker, but it was not, after all, the final form of the architecture that was to be created and launched Docker at one level managed. Here we can see the Docker boot, there will be a dockerd daemon, a containerd management process. Note that the dockerd process binding is listening on the/var/run/docker.sock file, it is obvious that Docker communication is used between uni ...

1. Material no jar version Windows platform Hadoop-2.6.1.zip Eclipse Decompression 2. Configure environment Variables 3. Local mode operation local file Conf.set ("Mapreduce.framework.name", "locals"); Conf.set ("Fs.defaultfs", "file:///&quo ...")

Phenomenon will host network cable unplugged, regionserver over a period of time will be shutdown out, regionserver abnormal timeout detection mechanism is controlled by which parameter? Regionsever exception shutdown log: 2017-08-03 21:17:42,762 WARN [Main-sendthread (ocscloud07:9501)]zookeeper. Clientcnxn:session 0x25ce ...

Algorithms in Machine Learning (1) - Random Forest and GBDT Based on Decision Tree Model Combination. Decision Tree This algorithm has many good features, such as training time complexity is low, the prediction process is relatively fast, the model is easy to display (easy to get the decision tree made of pictures) and so on. But at the same time, the single decision tree has some bad points, such as easy over-fitting, although there are some ways, such as pruning can reduce this situation, but not enough. Model combinations (say Boosting, Bagging, etc.) are related to decision trees ...

Zookeeper cluster mode can not deploy the cloud server [java.net.BindException: Unable to specify the requested address (Bind failed)] solution. The main text In the cloud server (Aliyun, Tencent cloud) on the deployment of Zookeeper cluster mode, there are many reasons for the failure, the Internet mainly refers to the port is occupied (not open) and firewall open two kinds of problems, a lot of similar blog, this article is not To repeat. If you've already made changes for both of the above two cases and still have not been successful, then maybe ...

According to the docker-compose installation tutorial provided by docker's official website, installing the latest docker-compose on ubuntu machines resulted in the following exception: Failed to connect to github-production-release-asset-2e65be.s3.amazonaws.com port 443: Connection Time-out installation process is as follows: $ sudo-i root @ far: ~ # cur ...

VoIP runs on a common data network rather than a telephone line. Voice data is shared with other types of data on a single network. To improve the voice quality, I transform and optimize the network to improve call quality and ensure a high-quality customer service experience. Delay, jitter, packet loss and burst are four QoS characteristics addresses. LAN priority voice communications, by setting the quality of service (QoS) in the router to distinguish between VoIP and voice traffic to achieve, if the system has bottlenecks, voice communications need to be in the network priority over other applications and Internet activities. Ensure a clear ...

PalindromeLinkedList wrote: # Definition for singly-linked list. # Class ListNode (object): # def __init __ (self, x): # self.val = x # self.next = None class Solution (object): def isPalindrome self, h ...

The concept of cloud acceleration is actually not a new concept. Previously, Google and Sogou have tried to use the browser for its definition, in their definition, the cloud acceleration is a real server through speed acceleration, to achieve online browsing speed of technology, compared to the traditional browser acceleration technology, this cloud acceleration technology really achieve the real speed of the promotion. In fact, this is just a browser-based definition, which is narrow and not broad enough, but it is the embryonic form of cloud acceleration. The application of cloud acceleration can also be used in many aspects, looking at the domestic, in addition to Sogou browser has proposed cloud plus ...

Tor Browser 4.0.6 Released, this release is mainly updated with the following information: Upgrade Firefox to 31.6.0 Meek upgrade to 0.16 OpenSSL upgrade to 1.0.1m details please pay attention to the release notes. Windows version download please click here to download the MAC version please click here GNU version download please click here Tor Browser Bundle is a based on Firefox ESR (Fi ...

Due to the impact of various factors, is to abandon the maintenance of jfinal plug-ins, fully maintain the new RESTful framework resty (http://git.oschina.net/dreampie/resty Or https://github.com/ Dreampie/resty), the search for maintenance of the user to take over the maintenance work, most plug-ins are also very simple, just need to feedback to the bug when the correction. Https://github.com ...