lmr tuning

even untimely, it should be understood. has been in the Java community for nearly 3 years, for some performance tuning topic I have been stuck in the mouth, just for last night saw a performance tuning article, I can't help it .Tomcat Performance Tuning:Locate the Conf directory under the Tomcat root directory and modify the contents of the Server.xml file . For this part of the

. Orderid,o1. Freightfrom Orders o1where O1. Freight>( SELECT AVG. O2. Freight) from Orders O2)The goal of SQL execution is to query orders that have more than the average shipping charge in the order.The clause that extracts the average freight here is a completely independent subquery that executes independently of the main query. At the same time here we take advantage of a scalar computation (AVG) so that it returns exactly one row.Look at the query plan for the statement:This query plan

From the editor to the optimization, I have been in accordance with the previous Director of the program to perform our website optimization work, but there is no ideal ranking results, the keyword ranking instability, the conversion rate is not high. After the accumulation of experience, I have some of my own attempts, that is to fine-tune the site, the unexpected is to improve the conversion rate, so today I recommend this article to those who have the same situation with me. One, what is fin

excerpt from: http://uule.iteye.com/blog/2114697Summary of JVM garbage collection and performance tuningSeveral strategies for tuning the JVMFirst, JVM memory model and garbage collection algorithm1. According to the Java Virtual Machine specification, theJVM divides the memory into: New (Young Generation) Tenured (old generation) Permanent generation (Perm) Where new and tenured belong to heap memory, heap memory is allocated fr

Fine-tuning, as the name suggests, is a small very subtle adjustment. Office fine-tuning technology is only a small function, but it can be applied to a lot of details of the operation, small tricks of great use. Do not believe that you look at the following skills, while looking at the operation, see is not. 1: Use fine tuning to quickly change text size

Objective Over the past decade, Oracle has become one of the most professional databases in the world. For IT professionals, it is important to ensure that Oracle's powerful features are used to improve the productivity of their companies. One of the most effective ways to do this is through Oracle tuning. It has a large number of tuning parameters and techniques to improve the performance of your Oracle d

Label:I believe a lot of friends, whether it is to do development, architecture, or DBA, are often heard of the word "tuning". Talk about "tuning", may make a lot of technical staff heart passion, also may make a lot of people feel distressed, do not know how to start. Of course, there are many people who are dismissive of this, because not everyone does the project is very high performance requirements. In

the memory pool, the allocation and usage of overall memory, and the number and time of garbage collection by different GC. You can manually perform GC view memory changes.It is useful to analyze Java memory issues for tuning, you learn the JVM memory model, and then you find that each value here has meaning.GC Algorithms and parameters have a significant impact on performance, note the number of garbage collections, the time, and the partial GC and

; by observing, in this case, there is no hardware bottleneck in the problem.2, network bottlenecks, can be determined by viewing the network utilization, a lot of ways, here is not introduced; but if it is in the LAN, and this is just a Web service type Web site, and the video class site is different, so in this case there is no network problem3, Linux operating system bottlenecks, Linux on the performance of the design to the kernel parameters too many, here can be the parameters of "Linux Ser

The following environments are representative of the general configuration and work environment of small and medium-sized enterprises. I hope this article will help you understand the MySQL database performance tuning method in Linux. 51CTO recommends the MySQL database getting started and proficient tutorial to you. Hardware preparation environment: Hard Drive: 16 SAS15KRAID5 with 512 MCacheCPU: Two AMD4 Cores The following environments are represent

AnglarJS, as an excellent Web framework, can greatly simplify the burden of front-end development. This article introduces seven suggestions for performance tuning of AngularJS, involving angularjs Performance Tuning knowledge. If you are interested in this article, learn about AnglarJS as an excellent Web framework, this greatly simplifies front-end development. Recently, Sebastian föstl said in an article

The last 2 months have been doing mobile phone and TV development, the development process encountered a variety of pits. Get fast New Year's day, finally put on the line. 2 months to dry down full of hard work, not so busy with their own preparation of the front-end performance tuning summary below, in order to facilitate the use of their own once again to be handy. Referring to the high-performance website Construction Guide-the essence of front-end

and the steady-state performance. Experienced debugging personnel can generally get more satisfactory debugging results. The most important problem in debugging is that when the performance of the system is unsatisfactory, you know which parameter should be adjusted and whether the parameter should be increased or decreased. to reduce the need for tuning parameters, the PI controller can be used first. In order to ensure the security of the system, a

, the smaller the number of buffer connections, and the larger the buffer becomes.13.5Tuning Core buffer size (UDP)AdjustmentUDP BuffersizeA. Adjust the bdp/#connections buffer A in the/etc/sysctl.conf file.The Input/reader in Bytes receives the data net.core.rmem_default the default value Net.core.rmem_max the maximum value B.Output/write in Bytes sends data Net.core.wmem_default Net.core.wmem_max B. Reload/etc/sysctl.conf sysctl–p13.6 Tuning TCP buf

Apache is a highly configurable software. It has a lot of features, but each one is expensive. To some extent, tuning Apache is the proper way to allocate resources, and it involves simplifying the configuration to include only the necessary content. Configuring MPM Apache is modular because features can be easily added and removed. At the core of Apache, the multi-processing module (multi-processing MODULE,MPM) provides this modular functionality-man

Comprehensive in-depth analysis of spark2--knowledge points, source code, Tuning, JVM, graph calculation, projectCourse View Address: http://www.xuetuwuyou.com/course/220The course out of self-study, worry-free network: http://www.xuetuwuyou.comA total of 14 chapters, 316 sections, the course from spark-related technical aspects of all-round analysis, and finally the actual project: User interactive behavior Analysis System, DMP User Portrait system,

When it comes to MySQL tuning, there are a lot of points that we can do, so combing, some tuning strategy, today just summarizes the tuning of server parametersActually speaking, the parameter tuning, my understanding is nothing more than two points: If it is InnoDB database, innodb_buffer_pool_size to open as

The author of this book is a leader in Java performance and Java HotSpot virtual machines, helping you to use modern soft practices to improve your practical life by summarizing energy, avoiding common mistakes, and tips and tricks.Using G1 to overcome the limitations of parallel, serial, and CMS garbage collectors learn about the various stages of G1 GC collection, including the young generation and the old era fine tuning your application under G1 '

value is set to a larger value, the young generation object will replicate multiple times in the Survivor area, which can increase the lifetime of the object in the younger generation and increase the introduction of the recovery in the younger generation. -xx:permsize: Set a persistent band -xx:maxpermsize: Set the maximum value for persistent generation (2) Tuning JVM tuning is primarily for memory manag

data (mean file, etc), # and a subset of \ Images for the style recognition T Ask. ! data/ilsvrc12/get_ilsvrc_aux.sh !scripts/download_model_binary.py models/bvlc_reference_caffenet ! Python examples/finetune_flickr_style/assemble_data.py \ --workers=-1--images=2000--seed=1701--label=5 3. Compare the differences between the two models !diff Models/bvlc_reference_caffenet/train_val.prototxt Models/finetune_flickr_style/train_val.prototxt Output here omitted 4. Learn with Python, comp