This document discusses load balancing techniques used by high-traffic websites like Yahoo to distribute server loads and improve performance. It explains that load balancing involves distributing network traffic, processing, and other loads across multiple servers to prevent any single server from being overwhelmed. Common load balancing methods mentioned are round robin DNS, hardware load balancing using network gateways, and software load balancing using integrated components in web and application servers.
slides are about load balancing as a concept and implementation of load balancing on computer technical level
slides show the server load balancing
different architectures , algorithms and examples
Web Server Technologies I: HTTP & Getting StartedPort80 Software
Introduction to HTTP: TCP/IP and application layer protocols, URLs, resources and MIME Types, HTTP request/response cycle and proxies. Setup and deployment: Planning Web server & site deployments, Site structure and basic server configuration, Managing users and hosts.
slides are about load balancing as a concept and implementation of load balancing on computer technical level
slides show the server load balancing
different architectures , algorithms and examples
Web Server Technologies I: HTTP & Getting StartedPort80 Software
Introduction to HTTP: TCP/IP and application layer protocols, URLs, resources and MIME Types, HTTP request/response cycle and proxies. Setup and deployment: Planning Web server & site deployments, Site structure and basic server configuration, Managing users and hosts.
Loadbalancing von Barracuda's Web Gateway - das Handbuch
Dieser Guide beschreibt die Konfiguration eines Loadbalancers für Barracuda's Web Gateway bzw Webfilter. Enthalten sind empfohlene Deployment Szenarios und Konfigurationsdetails.
Die Vorteile:
- keine Unterbrechung wenn ein Web Filter ausfällt
- für Wartungsarbeiten können Web Filter einfach ausgetauscht werden
- für zusätzliche Leistung können einfach weitere Content Filter zum Cluster hinzugefügt werden
An Efficient Distributed Control Law for Load Balancing in Content Delivery N...IJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
International Journal of Modern Engineering Research (IJMER) covers all the fields of engineering and science: Electrical Engineering, Mechanical Engineering, Civil Engineering, Chemical Engineering, Computer Engineering, Agricultural Engineering, Aerospace Engineering, Thermodynamics, Structural Engineering, Control Engineering, Robotics, Mechatronics, Fluid Mechanics, Nanotechnology, Simulators, Web-based Learning, Remote Laboratories, Engineering Design Methods, Education Research, Students' Satisfaction and Motivation, Global Projects, and Assessment…. And many more.
Web Server Technologies II: Web Applications & Server MaintenancePort80 Software
Supporting Web applications: server-side programming and Web application frameworks. Web server maintenance: Web Analytics (Logs and Log Analysis), Dealing with bots and spiders, Server and site monitoring, Tuning and acceleration, Programmatic administration.
ASIT Bangalore is the best institute for "REST API" and invites lot of people with technical back ground and experienced HR from corporate world as a part of pre-placement training, this actually helps us to perform better in our interviews. For more details please visit our website.
Web-Server Load Balancing, a process that distributes the load of various incoming requests to several servers (e.g. using a gateway that functions as a dispatcher), in an effort to balance the load among these servers in an optimal way. This thesis inspects the various methods and strategies of server load balancing, clearly identifying the advantages and disadvantages of each strategy. We present a working, high performance implementation of the content-aware traffic redirection strategy, using the most well known scheduling algorithms. We also present the results of testing the effectiveness of the implementation and the scheduling algorithms in several scenarios. Finally, based on our work, we concluded that what seem to be the best scheduling algorithms in the case of identical requests are the least CPU usage and the weighted random scheduling algorithms which have the best response time and the best throughput. While in the case of non-identical requests the weighted round robin and the least CPU usage have the least response time and the greatest throughput.
By: Abdul-Lateef Haji-Ali, Yael Jari,
Bashar Shehadeh, Mhd. Mamdouh Tarabishi
Wael Tayara
Supervised by: Dr. Ghassan Saba
Healthy breakfast recipes that taste good and work well with muscle building. Check here for Pre& Pro-Workout Healthy Breakfast Recipes!
http://urbanwired.com/health/healthy-breakfast-recipes-that-help-you-build-muscle/
Loadbalancing von Barracuda's Web Gateway - das Handbuch
Dieser Guide beschreibt die Konfiguration eines Loadbalancers für Barracuda's Web Gateway bzw Webfilter. Enthalten sind empfohlene Deployment Szenarios und Konfigurationsdetails.
Die Vorteile:
- keine Unterbrechung wenn ein Web Filter ausfällt
- für Wartungsarbeiten können Web Filter einfach ausgetauscht werden
- für zusätzliche Leistung können einfach weitere Content Filter zum Cluster hinzugefügt werden
An Efficient Distributed Control Law for Load Balancing in Content Delivery N...IJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
International Journal of Modern Engineering Research (IJMER) covers all the fields of engineering and science: Electrical Engineering, Mechanical Engineering, Civil Engineering, Chemical Engineering, Computer Engineering, Agricultural Engineering, Aerospace Engineering, Thermodynamics, Structural Engineering, Control Engineering, Robotics, Mechatronics, Fluid Mechanics, Nanotechnology, Simulators, Web-based Learning, Remote Laboratories, Engineering Design Methods, Education Research, Students' Satisfaction and Motivation, Global Projects, and Assessment…. And many more.
Web Server Technologies II: Web Applications & Server MaintenancePort80 Software
Supporting Web applications: server-side programming and Web application frameworks. Web server maintenance: Web Analytics (Logs and Log Analysis), Dealing with bots and spiders, Server and site monitoring, Tuning and acceleration, Programmatic administration.
ASIT Bangalore is the best institute for "REST API" and invites lot of people with technical back ground and experienced HR from corporate world as a part of pre-placement training, this actually helps us to perform better in our interviews. For more details please visit our website.
Web-Server Load Balancing, a process that distributes the load of various incoming requests to several servers (e.g. using a gateway that functions as a dispatcher), in an effort to balance the load among these servers in an optimal way. This thesis inspects the various methods and strategies of server load balancing, clearly identifying the advantages and disadvantages of each strategy. We present a working, high performance implementation of the content-aware traffic redirection strategy, using the most well known scheduling algorithms. We also present the results of testing the effectiveness of the implementation and the scheduling algorithms in several scenarios. Finally, based on our work, we concluded that what seem to be the best scheduling algorithms in the case of identical requests are the least CPU usage and the weighted random scheduling algorithms which have the best response time and the best throughput. While in the case of non-identical requests the weighted round robin and the least CPU usage have the least response time and the greatest throughput.
By: Abdul-Lateef Haji-Ali, Yael Jari,
Bashar Shehadeh, Mhd. Mamdouh Tarabishi
Wael Tayara
Supervised by: Dr. Ghassan Saba
Healthy breakfast recipes that taste good and work well with muscle building. Check here for Pre& Pro-Workout Healthy Breakfast Recipes!
http://urbanwired.com/health/healthy-breakfast-recipes-that-help-you-build-muscle/
NKM Machine has been dedicated to design and manufacture of our range of Double Arm Mixer, of which the most commons and popular models are our SGK series Sigma Kneader and DPK series Dispersion Mixer. For more details visit: http://www.powder-mixing.com/kneading-mixing.html
A Modified Genetic Algorithm based Load Distribution Approach towards Web Hot...idescitation
Web hotspot is a serious problem often experienced in case popular websites. It
provides dramatic load spike in a website, which occurs when a huge number of users
accessing the same website. A prominent solution to this problem is server load balancing.
Dynamic load balancing involves allocation of requests to the server or processor
dynamically when they arrive. For effective load balancing, a near-optimal schedule of
incoming requests or processes must be determined “on-the-fly”, so that execution of
requests can be completed in shortest possible time. So we have proposed a Genetic
Algorithm based load balancing scheme which relies on a process scheduling policy. Genetic
Algorithm provides to search for the optimal solution out a search of candidate solutions. It
follows the survival-of-the-fittest principle, to achieve the optimal solution, through a
number of generations. The proposed algorithm is evaluated for various population size and
number of generations, to maximize the processor utilization of nodes/ processors in the
system.
The Grouping of Files in Allocation of Job Using Server Scheduling In Load Ba...iosrjce
IOSR Journal of Computer Engineering (IOSR-JCE) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of computer engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in computer technology. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Enhanced Dynamic Web Caching: For Scalability & Metadata ManagementDeepak Bagga
Abstract: These days web caching suffers from many problems like scalability, robustness, metadata management etc. These problems degrade the performance of the network and can also create frustrating situations for the clients. This paper discusses several web caching schemes such as Distributed Web Caching (DWC), Distributed Web Caching with Clustering (DWCC), Robust Distributed Web Caching (RDWC), Distributed Web Caching for Robustness, Low latency & Disconnection Handling (DWCRLD). Clustering improves the retrieval latency and also helps to provide load balancing in distributed environment. But this cannot ensure the scalability issues, easy handling of frequent disconnections of proxy servers and metadata management issues in the network. This paper presents a strategy that enhances the clustering scheme to provide scalability even if size of the cluster grows, easy handling of frequent disconnections of proxy servers and a structure for proper management of cluster’s metadata. Then a comparative table is given that shows its comparison with these schemes.
AWSQ: an approximated web server queuing algorithm for heterogeneous web serv...IJECEIAES
With the rising popularity of web-based applications, the primary and consistent resource in the infrastructure of World Wide Web are cluster-based web servers. Overtly in dynamic contents and database driven applications, especially at heavy load circumstances, the performance handling of clusters is a solemn task. Without using efficient mechanisms, an overloaded web server cannot provide great performance. In clusters, this overloaded condition can be avoided using load balancing mechanisms by sharing the load among available web servers. The existing load balancing mechanisms which were intended to handle static contents will grieve from substantial performance deprivation under database-driven and dynamic contents. The most serviceable load balancing approaches are Web Server Queuing (WSQ), Server Content based Queue (QSC) and Remaining Capacity (RC) under specific conditions to provide better results. By Considering this, we have proposed an approximated web server Queuing mechanism for web server clusters and also proposed an analytical model for calculating the load of a web server. The requests are classified based on the service time and keep tracking the number of outstanding requests at each webserver to achieve better performance. The approximated load of each web server is used for load balancing. The investigational results illustrate the effectiveness of the proposed mechanism by improving the mean response time, throughput and drop rate of the server cluster.
WebOfThings: Paper for my presentation on DesignWest Silicon Valley in San Jose, where I presented an Embedded Web Server for HTML5, using SSE - Server Sent Events, in a very efficient and fast implementation on ARM Cortex-M.
In order to optimize server performance for whatsoever reason, you need to start by monitoring the server. In most cases, before server monitoring commences, it is common practice to establish baseline performance metrics for the specific server. Baseline performance metrics are established by measuring the performance of a particular server under various conditions, at different times of the day, week, and month, and when the hardware and software configuration changes. Based on the baseline metrics which you define for the server, you would need to optimize the server when performance of the server by far exceeds your baseline metrics.
Cloud comparison hosting and choice of service providerPatrick Ogbuitepu
This write-up aims at presenting the reader with the benefits and drawbacks of using a cloud hosting service to ensure an availability of over 99% with minimum possible operating costs. The write-up would briefly explore existing hosting plans and compare the key features of 4 different cloud hosting service providers.
2. A high-volume site like Yahoo! knows that the actual
quality of service any web server provides to end users
basically depends on network-transfer speed and server
response time. Network-transfer speed refers to the
Internet-link bandwidth while server-response time
depends upon resources including fast CPU, lots of RAM
and good I/O performance. Once these resources are
exhausted and the web-server is encountering heavy
traffic, a problem would surely arise.
4. A problematic situation pertaining to difficulty in
handling high volumes of incoming traffic can be solved
either through installing more RAM on existing machines
or replacing the CPU with a faster one. The use of faster
or dedicated SCSI controllers and disks with shorter
access time can also be done. Software can be tuned so
that the operating system parameters and web server
software can be adjusted to achieve better performance.
5. An alternative approach is to improve performance by
increasing the number of web servers. This approach
would attempt to distribute traffic unto a cluster of
back-end web servers that need not be large-scale
machines. Web server scalability is achieved when more
servers are added to distribute the load among the
group of servers or server cluster.
6. This is what load balancing is all about. It involves the
fine tuning of a computer system, network or disk
subsystem in order to more evenly distribute the data
and/or processing across available resources. Load
balancing is distributing, processing and
communications activity evenly across a computer
network so that no single device is overwhelmed. Busy
websites usually use two or more web servers in a load
balancing scheme so that when one server gets
overwhelmed with requests, traffic is forwarded to
another server with more capacity.
7. There are two probable reasons why a company could
want to load balance traffic across firewalls. One is for
purely technical reasons and the other is centered on
winning business. The technical aspect should be quickly
addressed as soon as funds and environment allow.
8. When there is only one web server responding to all
incoming HTTP requests for a website, it may not be
able to perform accordingly especially if the website has
gained popularity. Loading of web pages will be very
slow and some users would have to wait for their
requests to be processed. It can come to a point where
upgrading the server hardware is no longer cost
effective due to the increased traffic and connections to
a website.
9. Yahoo! was granted a patent from a filing done in 1999
regarding coordinating information between multiple
servers that share information as well as servers that
may cache some of the information. Load balancing
devices are becoming very common in supporting high-traffic
websites. These devices evolve as websites grow
in terms of size, complexity and traffic flow.
10. The presence of multiple web servers in a server group
requires that HTTP traffic be evenly distributed among
the servers. These servers should appear as a single web
server to the web client. The load balancer simply
intercepts each request and redirects it to an available
server in the server cluster.
12. Load balancing can be achieved in a number of ways.
Choice would depend on the individual requirement,
available features, complexity of implementation and
the cost. The user company would have to determine its
circumstances to determine which option would work
best.
13. The Round Robin DNS Load Balancing is one of the early
adapted load balancing techniques. The built-in round
robin feature of BIND of a DNS server facilitates cycling
through the IP addresses corresponding to a group of
servers in a cluster. It is a fairly simple and inexpensive
method which is very easy to implement. However, its
downside is that the DNS server does not have any
knowledge of server availability thus may continually
point to an unavailable server. It has the ability to
differentiate by IP address but not by server port. There
is also the possibility that the IP address is cached by
other name servers which would result to request not
being sent to the load balancing DNS
15. In Hardware Load Balancing, hardware load balances
route TCP/IP packets to various servers in a cluster. This
method is said to provide a powerful topology with high
availability. It uses circuit level network gateway to
route traffic. Its one downside is the higher cost incurred
as compared to other methods.
16. The most commonly used method is Software Load
Balancing. Load balancers often come as an integrated
component of expensive web server and application
server software packages. This method is more
configurable based on requirements and can incorporate
intelligent routing base on multiple input parameters.
An additional hardware needs to be provided to isolate
the load balancers.
18. When HTTP requests are assigned to any server picked
randomly among the group of servers, this is called
random allocation. It is possible that one server may be
assigned more requests than the others, but generally
each server gets its share of the load. It can be very easy
to implement but the risk of overloading one while
under-utilizing another is big.
19. The IP sprayer assigns the requests to a list of the
servers on a rotating basis when the round-robin
allocation is used. The first request goes to a randomly
picked server in a group so that the entire first request
need not go to the same server especially if more than
one IP sprayer is involved. The circular order is followed
in redirecting the traffic for subsequent requests. The
server which has been assigned a request moves to the
end of the list to ensure that all servers are equally
assigned. The allocation is much orderly than random
but it may not be enough based on processing overhead
required and when there are differences in server
specification in a server group.
20. The shortcoming of the round-robin allocation has been
eliminated by the weighted round-robin version. In this
case, a server that is capable of handling twice as much
load as the other can get a weight of two. This means
that the IP sprayer will assign two requests to the
powerful server as against one request assigned to the
weaker one. This takes care of the capacity of the
servers in the group. However, it does not consider the
advanced load balancing requirements like processing
time for individual request. An efficient load balancer
should be capable of intelligent monitoring that would
help it direct requests to the server that is more capable
of handling them.