emc rack

mongrel--pre Install mongrel instead of Webrick and encounter the following issues (Ruby version 1.9.2 rails version 3.1.3) Error:error Installing Mongrel:Error:failed to build gem native extension. The reason is that mongrel 1.1.5 is incompatible with Ruby 1.9.x. You can install a different version by installing Gem Install mongrel--pre Or Gem install mongrel-v 1.2.0.pre2--pre--sourcehttp://ruby.taobao.org Successfully installed After the installation is complete, run:

Since the specification and number of information points of large, medium, and small computers are determined by host devices, wiring designers generally only collect the types and quantities of their information points, rather than wiring them. Therefore, the number of information points discussed in cabling planning mainly comes from server cabinets. Before counting the number of information points, it should be noted that the number of information points on each server terminal NIC/network bl

equipment ). The next location where frequent power measurements are performed is the uninterruptible power supply (UPS ). If IT only supplies power to IT devices, this data can be used as the denominator for PUE computing. However, UPS may also provide power for rack-mounted refrigeration devices. The third position of power measurement is the rack itself, which features the Distribution Unit (PDU) of the

at a time (except for append and truncation), and there is a writer at any time. Namenode makes all decisions about block replication. It regularly receives heartbeat and blockreport from each datanode in the cluster. When heartbeat is received, datanode is running properly. Blockreport contains a list of all blocks on datanode. Copy placement: Step 1 The placement of copies is critical to the reliability and performance of HDFS. Optimized copy placement separates HDFS from most other distribut

problems, especially the EMC and EMI Problems in High-Speed PCB wiring. There are many conflicts and they are a headache. How can we solve these conflicts? Answer: 1. Basically, it is right to divide and isolate the modulus/number. It should be noted that the signal line should not be crossed through a separate place (moat), or the returning current path of the power supply and signal should be too large.2. the crystal oscillator is a simulated posit

pair wires, and optical fiber cables when selecting voice communication, data communication, and image communication transmission media. Voice communication: 3 categories or higher 100 Ω unshielded twisted pair wires; General Data Communication: 5 categories of 100 Ω unshielded twisted pair wires, 150 Ω shielded twisted pair wires; high-speed data communication: 2-core 62.5/125 μm optical fiber; Visual Communication: 5 categories of 100 Ω unshielded twisted pair wires, 2-core 62.5/125 μm optica

Answers to four questions about the shielded Cabling System In integrated wiring, two types of wiring are classified from the largest category: unshielded wiring and unshielded wiring. the unshielded wiring was first originated in Europe, it mainly adds a metal shielding layer to the external of a common unshielded wiring system. The principle is to use the emission, absorption, and skin effect of the metal shielding layer to prevent electromagnetic interference and electromagnetic radiation, t

Composition application -- VMM Memory Allocation Manager application -- VMM Hardware Abstraction Layer application -- VMM Data Stream Scoreboard application -- VMM Macro Library This is an exciting news! With the importance of verification in icdesign being paid more and more attention, EDA giants are launching new strategies to attract potential customers. From AVM open source to OVM open source to vmm open source, we can see a series of positive initiatives that are constantly pushing for

details, to the needle printer's use and maintenance of a look back, hoping to "new" people to bring a certain harvest!Start by changing the ribbon to make the needle efficient "service"As with toner and ink cartridges, ribbons in fact belong to a printing consumables, but it only belongs to the needle-type printer proprietary; Usually, every once in a while, we need to change the ribbon. Although changing the print ribbon is not a very difficult thing, but the type of printing is different, th

/LIB/RAILS/INITIALIZABLE.RB: Wu:inch' Each'from/home/diudiugirl/.rvm/gems/ruby-2.3.0/gems/railties-3.2.22.1/LIB/RAILS/INITIALIZABLE.RB: Wu:inch' Run_initializers'from/home/diudiugirl/.rvm/gems/ruby-2.3.0/gems/railties-3.2.22.1/LIB/RAILS/APPLICATION.RB:136:inch' initialize!'from/home/diudiugirl/.rvm/gems/ruby-2.3.0/gems/railties-3.2.22.1/LIB/RAILS/RAILTIE/CONFIGURABLE.RB: -:inch' Method_missing'FROM/VAR/WWW/ASHELF/CONFIG/ENVIRONMENT.RB:5:inch' 'from/home/diudiugirl/.rvm/gems/ruby-2.3.0/gems/activ

admin and admin. If you need to find out which sqlite library is used by your apache/php installation, browse to itdb/phpinfo. php The main functions are as follows: ? Items: specs, warranties, s/n, IP info, what other H/W relates/connects to this H/W, item status, event log, assignees? Software: specs, license info ,...? Relations: where each software is installed, license QTY, component relations, contract relations to software/hardware/invoices? Invoices: purchase proofs depicting date, v

shown in Figure. In the actual environment, Facebook does not have only three racks, but has hundreds of racks. In addition, the figure shows the rack-mounted (TOR) switches in each rack. The Rack-mounted switch acts as an intermediary between the server and the upstream aggregation switch. Figure A: rack-mounted (TO

increase, background threads merge them into a larger, ordered file to save time for subsequent merges. In fact, regardless of the map or the reduce side, MapReduce is repeated to perform the sort, merge operation, now finally understand why some people say: sort is the soul of Hadoop.3. The merging process produces many intermediate files (written to disk), but MapReduce makes the data written to disk as small as possible, and the result of the last merge is not written to disk, but is entered

define the distance between them with the bandwidth before two nodes. in practice, so many nodes, in every two nodes between the measurement of bandwidth is unrealistic, Hadoop took a compromise way, it takes the network structure as a tree, the distance between two nodes is two points up to the father, grandfather, ancestor ... Until two nodes have a common ancestor, they both walk the sum of the steps. No one rules how many levels a tree must have, but the usual practice is to be divided into

/B580 attached to the Panel, assets, and other flat surfaces. B580 is required for outdoor environments. According to the standard, the printing is mainly required to comply with the UL969 standard, and is a hot transfer printing method. At the same time, there are two main printing solutions for Beidi, one is mass printing, the printer model is IP300, And the handheld printer is mainly applicable to the network architecture of qiandian and below. The printer models are TLS2200 and BMP 21, as sh

designed to use a non-intelligent general cabling system, as the project infrastructure gradually completed and the customer's intention to negotiate a higher service requirements, operators realize the traditional manual management maintenance mode inefficient, in order to improve service level and brand effect, improve management efficiency, save operating costs, The operator decides to change the design of the data center cabling system, uses the intelligent cabling system, uses the electron

number of blocks in each rack cannot be changed. 2. the system administrator can run a command to start the data redistribution program or stop the data redistribution program. 3. Block cannot temporarily use too many resources, such as network bandwidth, during the process of moving. 4. the normal operation of Name node cannot be affected during execution of the Data redistribution program. Based on these basic points, the current logic flow

Problems related to shielding systems in Integrated Wiring In the Integrated Wiring System, unshielded and unshielded systems are widely used. The shielding system comprehensively utilizes the balanced principle of twisted pair wires and the shielding effect of the shielding layer. It has good electromagnetic compatibility and can prevent electromagnetic interference and electromagnetic radiation. The advantages of shielded cabling can help the rapid development of the Internet. Many large dat

., which are often collectively referred to as "Shuffle" or "mixed wash". The purpose of the shuffle is to comb, sort, and distribute the data to each reducer in a scientific way so that it can be efficiently calculated and processed (no wonder people say that this is where miracles happen, so there are so many flowers in it.) )If you are a Hadoop Daniel, look at this picture may soon be jumping out, no! There is a spill process ...Wait, about spill, I think just a realization of the details, in

of data warehouse, the so-called Data Warehouse is an analytic database for a large number of data which has been formed by OLTP, which is used to deal with the important decision information such as business intelligence, decision support and so on. Data Warehouse is the processing and analysis of historical data after the database is applied to some degree is a tool that handles two different uses. 2. Exadata Technology Architecture 2.1 Oracle Exadata Components let's start wit