how to reduce bufferbloat

Recently read the "Redis combat", summed up some of the optimization methods mentioned in How to reduce the Redis memory usage: Use the correct data structure key length smaller occupy memory smaller (add up) value can be processed part of the data structure in the length of the smaller, A small number of cases will be using space-saving algorithm storage, can be combined with sharding to reduce total memor

MongoDB: Map-Reduce, mongodbmap-reduce Map-reduce is a data processing program (paradigm) that considers large data to obtain useful aggregation results. For map-reduce operations, MongoDB provides mapreduce commands. Consider the following map-reduce operation: In this map

Python ---- reduce is used in this way. Python ---- reduce Official explanation: ApplyFunctionOf two arguments cumulatively to the itemsIterable, From left to right, so as to reduce the iterable to a single value. For example,Reduce (lambda x, y: x + y, [1, 2, 3, 4, 5])Calculates(1 + 2) + 3) + 4) + 5). The left argumen

Python functools. reduce usage, functools. reduce After python 3.0, reduce is no longer in the built-in function. to use it, you need to import reduce from functools. Reduce usage Reduce (function, sequence [, initial])-> valueApp

people may think that each request spends most of the time on downloading resources, let's see Blogjava resources Download Waterfall Graph (each color represents the stage corresponding to the above 5 stages):You may be surprised to see that the time spent in the waiting phase is much more than the actual download time, tell us:1. The majority of the time spent on each request is at other stages, not in the download resources phase2. Small resources will still take a lot of time at other stages

5 things that will reduce the speed of the Wi-Fi network, will reduce the wi-fi5 By using the old protocol, overlapping channels, and low data rates, Wi-Fi networks may become slower. The following describes how to solve these and other performance problems. Wi-Fi (Wireless LAN) is quite easy to change. Competition between Wi-Fi devices and dynamic communication media of radio waves makes them a sensitive

Implement only one map or reduce method for each map or reduce task By default, the map and reduce methods are executed once for each In fact, you only need to reload the run method in the map class and reduce class of the user program to traverse each input Run: Package the code into a jar and run it in the cluster

Use plug-in technology to call ShareSDK to reduce application volume and sharesdk to reduce I. Introduction: ShareSDK is componentized using the ApkPlug plug-in framework to dynamically load and reduce application volume as needed. ShareSDK is a great mobile social sharing and commenting tool. I believe we can't do without it during application development. Howe

resources, let's take a look at the Blogjava resource download waterfall (each color represents a phase corresponding to the above 5 stages): Looking at the above picture you may be surprised that the time spent in the waiting phase is much more than the actual download time, the above figure tells us: 1. Most of the time spent on each request is at another stage, not at the download resource stage 2. Small resources will still spend a lot of time in other stages, but the download phase will

How to effectively reduce repeated code and effectively reduce repeated code Repeated code has always been the enemy of maintainability. One of the important tasks of refactoring is to remove repeated code, effectively reducing repeated code, which can greatly improve the scalability of the software. In Android development, duplicate code is easily generated. Because Android is a component and template-ba

CPU is the central processor. This is a super-large-scale integrated circuit. It is the computing core and control core of a computer and the main part of the computer. How can we solve this problem if the cpu usage of win7 is too high?Method 1: reduce the computer startup service items. Click "start" in the lower left corner of the desktop and enter "msconfig" in the "run" dialog box, as shown in the following figure:Aft

Hello everyone, in the previous two articles I have analyzed two aspects of the problem, one is to say that the site was down after some of the phenomenon, mainly in order to meet a similar phenomenon when you can soberly aware of the end of their own website has not been down the right, another is said the site was down the right of several major reasons, Mainly to help you find some of their own site to reduce the right of improper operation, timely

1. Use as few static variables as possible, as it will always consume memory,2. Use as few string strings as possible for stitching and adding. Because a string is a fixed length, each addition creates a new temporary object, generates a garbage object, and uses StringBuffer as much as possible because the StringBuffer is variable length.3. When the object is exhausted, the null value is used so that the JVM garbage collection will not be judged and recycled directly.4. Try not to display the ca

supports "tickless" technology, which has been applied to fedora 7. Van der Van says the 2.6.21 Linux kernel can save a lot of energy. In the most energy-efficient state, the Intel mobile chip consumes 1.2 watts, and "Tickless" enables the processor to run in the most energy-efficient state. The tickless kernel still records time, but it takes a different approach. No longer frequently checking whether there is work to be done, and when it is known that there is work to be done, the kernel sc

supports "tickless" technology, which has been applied to fedora 7. Van der Van says the 2.6.21 Linux kernel can save a lot of energy. In the most energy-efficient state, the Intel mobile chip consumes 1.2 watts, and "Tickless" enables the processor to run in the most energy-efficient state. The tickless kernel still records time, but it takes a different approach. No longer frequently checking whether there is work to be done, and when it is known that there is work to be done, the kernel sc

1. In standard mode, slide the screen to the left.2. Click "Set".3. Click "Show".4. Click "Single Hand Operation".5. Click on the "Shrink screen size" right slider, green Representative open.6. Through fast and continuous press home key three times to reduce the display size (to enable one-handed operation, please disconnect the USB cable), has successfully reduced the screen size, click the "Arrow" icon, you can adjust the single hand input screen to

a map task to complete, and a map task start and initialization time is much larger than the logical processing time, it will cause a lot of waste of resources. Also, the number of maps that can be executed at the same time is limited. 4. It's easy to be sure that each map handles close to 128m of file blocks.The answer is not necessarily. For example, there is a 127m file, the normal will use a map to complete, but this file only one or two small small paragraph, but there are tens of million

Document directory IV. For details about map tasks, see V. Reduce task details Vi. Distributed support VII. Summary 2. Distributed Computing (MAP/reduce) Distributed Computing is also a broad concept. In this case, it refers The distributed framework designed by the MAP/reduce framework. In hadoop, distributed file systems serve a wide range of distributed

Official explanation: Apply function of two arguments cumulatively to the ' items of iterable, from left to right, so as to reduce the iterable to A single value. For example, reduce (lambda x, Y:x+y, [1, 2, 3, 4, 5]) calculates ((((1+2) +3) +4). The left argument, X, are the accumulated value and the right argument, y, are the update value from the iterable. If the optional initializer is present,

Map-reduce is a data processing program (paradigm) that considers large data to get useful aggregation results. For map-reduce operations, MongoDB provides the MapReduce command.Consider the following map-reduce operation:In this map-reduce operation, MongoDB applies a map operation to each input document (for example,