• Implementing token bucket algorithm using redis


    In the current limiting algorithm, there is a token bucket algorithm, which can deal with short burst traffic, which is particularly useful for the situation of uneven traffic in the real environment. It will not trigger current limiting frequently and is friendly to the caller. For example, the current limit is 10qps, which will not […]

  • Daily recommendation 07.04


    Share the popular excellent foreign designs and open your eyes every day; Number four groups, accumulate a little every day to improve design aesthetics# Applet #ui 01. The most popular UI design of weather application https://www.uplabs.com/posts/most-trending-ui-design-for-weather-app 02. NFT mobile application UI design https://www.uplabs.com/posts/nft-mobile-app-ui-design 03. Stock application exploration – Adobe XD https://www.uplabs.com/posts/stocks-app-exploration-adobe-xd-330f6f25-4e6b-46cc-b844-4df7e387c047 04. Clothing – App […]

  • Performance comparison between Apache pulsar and Kafka: latency (test results)


    It takes 7 minutes to read this article This series of articles will focus on the delay of pulsar and Kafka. The previous two articles have introduced the test method (green part in the figure below) and test details (blue content in the figure below). You can click the following title to view it directly: […]

  • Record the problem of continuous increase of online server memory, sort out and summarize


    1、 Problem phenomenon 2、 Project background The online web service is nginx + php7 + mysql Online server configuration: 8-core 16g PHP FPM configuration: pm = static pm.max_children = 500 ; pm. max_ Requests = 5000 // this configuration is not enabled 3、 Cause analysis of continuous increase of memory After checking the configuration of […]

  • HPA resources of container scheduling system k8s


    Earlier, we learned about using Prometheus to monitor nodes and pod resources on k8s. For review, please refer to:https://www.cnblogs.com/qiuhom-1874/p/14287942.html; Today, let’s learn about the use of HPA resources on the next k8s page; The full name of HPA is horizontal pod autoscaler, which literally means horizontal pod autoscaler; In short, the main function of HPA […]

  • Three methods to modify the limit of open files in Linux


    When a file is opened for access, the operating system temporarily assigns a number called file handle. A special area of main memory is reserved for file handles. The size of this area determines how many files can be opened at a time. Processes on Linux are subject to many restrictions, which also prevent them […]

  • Ape master sets the playback source method when playing RTSP applet with VLC in chrome


    If single playback is not satisfied and multiple simultaneous playback is realized, the following settings can be made in the HTML code: <iframe name=”VLCApplet” id=”VLCApplet” frameborder=”0″ align=”left” width=”550″ height=”540″ scrolling=”no> <param ID=”2″ Play=”http://www.yuanmaster.com/DAHUARTSP.mp4″ /> <param ID=”3″ Play=”rtsp://wzh:[email protected]:554/h264/ch1/main/av_stream” Caching=”500″ /> </iframe> Or use it directly <div id=”VLCApplet” class=”VLCApplet” <param ID=”2″ Play=”http://www.yuanmaster.com/DAHUARTSP.mp4″ /> <param ID=”3″ Play=”rtsp://wzh:[email protected]:554/h264/ch1/main/av_stream” Caching=”500″ […]

  • Question 29: how to understand bucket sorting?


    What is bucket sorting? Bucket sorting is an upgraded version of counting sorting. In some sorting scenarios, counting sorting cannot be used (the value is out of range or not an integer). Divide the data into a limited number of buckets and sort each bucket separately (it is possible to use other sorting algorithms or […]

  • Leetcode 401 combinatorial problem


    func readBinaryWatch(turnedOn int) []string { if turnedOn >= 9 { //Panic (“incorrect representation”) return []string{} } maxHnum := 3 maxMnum := 5 returnData := make([]string, 0, 255) for hourNum, minuteNum := 0, 0; hourNum <= maxHnum; hourNum++ { minuteNum = turnedOn – hourNum if (minuteNum < 0) { break; } if minuteNum >maxMnum { continue […]

  • Introduction to Python office 3: xlrd operation worksheet


    Worksheet 1 import xlrd 2 3 # accept worksheet 4 data=xlrd.open_workbook(“data.xlsx”) 5 # query the opening status of the first worksheet 6 print(data.sheet_loaded(0)) 7 # open all worksheets and output them as a list 8 print(data.sheets()) 9 print(data.sheets()[0]) 10 # get worksheet with index 0 11 print(data.sheet_by_index(0)) 12 # get a worksheet with a specific […]

  • Querying the number of CPU cores in Linux


    Take a Linux server as an example. This Linux includes twoIntel(R) Xeon(R) CPU E5-2630 v4 @ 2.20GHz  CPU. A single CPU includes 10 CPU cores and 20 logical CPU cores. Specific official introduction:  E5-2630 V4。 Let’s find the corresponding parameters through linux commands to see whether they comply with the official introduction, mainly to check/proc/cpuinfoInformation […]

  • Partial least squares (PLS) regression model, outlier detection and variable selection in MATLAB


    In this paper, partial least squares (PLS) regression (PLSR) model and prediction performance evaluation are established. In order to establish a reliable model, we also implement some common outlier detection and variable selection methods, which can remove potential outliers and “clean” only using a subset of the selected variables  ” Your data. step PLS regression […]