Multicast-based Distributed LVS (MD-LVS) for improving. scalability and availability

Size: px
Start display at page:

Download "Multicast-based Distributed LVS (MD-LVS) for improving. scalability and availability"

Transcription

1 Multicast-based Distributed LVS (MD-LVS) for improving scalability and availability Haesun Shin, Sook-Heon Lee, and Myong-Soon Park Internet Computing Lab. Department of Computer Science and Engineering, Korea University, Korea {shinsun, tonaido, Abstract However, the availability and scalability of cluster system is low, since this kind of solution creates a single-point-of-failure and the total throughput of cluster is limited by the performance of Load Balancer. In distributed IP cluster, every host in a web server cluster acts both as a Load Balancer and as a real server. However, this approach may increase the CPU workload of all the hosts to process the packetfiltering and load balancing. In this paper, we propose the Multicast-based Distributed LVS (MD-LVS), which combines centralized IP

2 cluster and distributed IP cluster. There are multiple Load Balancers and each Load Balancer has an individual and independent cluster group, which consists of several real servers. This mechanism efficiently can improve scalability and availability of cluster system, since it is easy to expand the cluster system and may avoid the entire system failure. 1. Introduction With the explosive growth of the World Wide Web, some popular web sites are getting thousands of hits per second. As a result, clients (browsers) experience slow response times and sometimes may not be able to access some web sites at all. Clustering with a single-system image view is the most commonly used approach to increase throughput of a Web site. With a server cluster, multiple servers behave as a single host, from client s perspective[1,2,3,4,5,6,7]. There are two types of clustering architecture: centralized IP cluster and distributed IP cluster. Centralized IP cluster consists of one Load Balancer and several real servers. Load Balancer distributes incoming requests of clients to an appropriate real server based on load characteristics. The centralized IP cluster includes LVS (Linux Virtual Server) as S/W load balancing method[1,2,3,11], and MagicRouter, LocalDirector and TCP Router as H/W load balancing method[9,10]. Real server makes the HTTP services and FTP services. However since this kind of solution creates a single-point-of-failure in the system, the availability is low. In

3 addition, the scalability is low, since the total throughput of cluster is limited by the performance of Load Balancer. The Load Balancer bottleneck becomes more critical compared to the network bottleneck and it limits the scalability of such servers in processing large number of simultaneous client requests. In distributed IP cluster, a collection of hosts works together to serve Web requests. Every host in a web server cluster acts both as a Load Balancer and as a real server. This approach includes DPR (Distributed Packet Rewriting) and ONE-IP. Distributed designs have the potential for scalability and cost-effectiveness. However, this approach may increase the CPU workload of all the hosts to process packet-filtering and load balancing. Since all the hosts individually have to process the load balancing, the service capability of each node may be decreased also. In addition, when one of hosts fails, the others have to reconfigure the system state information and load distribution information[4,5,6]. In this paper, we propose the Multicast-based Distributed LVS (MD-LVS). In structural aspect, we combined centralized IP cluster system and distributed IP cluster system. There are multiple Load Balancers and each Load Balancer has an individual and independent cluster group, which consists of several real servers. This mechanism can improve scalability and availability of cluster system, since it is easy to expand the cluster system and may avoid the entire system failure. So this can open a new cluster paradigm. The rest of the paper is organized as follows: Section 2 gives a related work of IP clustering. Section 3 presents our main idea, Multicast-based Distributed LVS and section 4 describes prototype implementation. Finally, section 5 concludes this paper.

4 2. Related Work 2.1 Centralized IP Cluster approach Centralized solution requires one Load Balancer, which distributes incoming packets to one of real servers, and several Real Servers, which supports HTTP and FTP service and so on. This approach is the most general way in cluster system and easy to implement of load balancing algorithm. However, it may create a single - point-of-failure and single -point-of-overload in the system, and requires the special purpose hardware as Load Balancer[1,2,3,9,10,11]. (1) S/W load balancing LVS[1,2,3,11] is built on a cluster of loosely coupled independent servers. This is developed by open project. LVS is now implemented in two ways. One is virtual server via NAT (Network Address Translation); the other is virtual server via LVS-DR (Direct Routing) and LVS-Tunneling. The virtual server code is now developed based on Linux IP Masquerading code in the Linux kernel 2.0 and 2.2, and some of Steven Clarke s port forwarding code is reused. It supports both TCP and UDP services, such as HTTP, Proxy, DNS and so on. In LVS-NAT, all the packets from and to clients pass through the Load Balancer. So the CPU load of Load Balancer may be concentrated seriously. In other hand, in LVS-DR and LVS-Tunneling, only incoming packets from clients pass through the Load Balancer. As a result, the scalability may be increased

5 somewhat. (2) H/W load balancing The responsibility of distributing requests to individual hosts in a cluster, several research groups hence suggested the use of a local router to perform this function. For example, there are MagicRouter of Berkely, TCP Router of IBM, and LocalDirector of Cisco, which are a packet-filter-based approach to distributing network packets in a cluster, and act as a switchboard that distributes request for Web service to the individual real servers in the cluster[9,10]. MagicRouter and LocalDirector use the Network Address Translation approach and is similar to LVS- NAT[9,10]. However, the MagicRouter doesn t survive to be a useful system for other users, the LocalDirector is too expensive, and they only support part of TCP protocol. TCP Router uses the modified Network Address Translation approach to build scalable web server and is similar to LVS-DR. TCP Router

6 changes the destination address of the request packets and forwards the chosen server, that server is modified to put the TCP router address instead of its own address as the source in the reply packets. The advantage of the modified approach is that the TCP router avoids rewriting of the reply packets. The disadvantage is that it requires modification of the kernel code of every server in the cluster. These approaches require using special-purpose hardware as Load Balancer. So cost is very expensive and the scalability is very low since the port number is fixed. 2.2 Distributed IP cluster approach Adding a second server to the site requires no special hardware, introduces no single-point-of-failure, and utilized the added capacity to scale both the connection routing and connection service capacities equally. In structural figure, DPR combines RR-DNS and LVS-DR (or LVS-Tunneling). That is, entry point of cluster is distributed by RR-DNS method and load balancing of cluster itself is achieved as LVS-DR or LVS -tunneling method by individual node[4,5,6,7,8]. (1) DPR In DPR[5,6], every host in a Web server cluster acts both as a real server and as a connection router. Thus, unlike existing solutions that rely on a single, centralized connection router, DPR enables both the service and

7 the routing responsibilities to be shared by all hosts in the cluster. Distributing the connection routing functionality allows for true scalability, since adding a new host to the cluster automatically adds enough capacity to boost both Web service and connection routing capacities. To enable a stateful routing of requests using DPR, each machine keeps an updated list of all other machines within the cluster, with information such as their IP addresses and current load. Hosts intermittently broadcast their load to the other machines (using multicast UDP packets). This information is used by a server to determine whether an incoming request should be re -routed or whether it should be served locally. Also, each machine keeps routing tables with information about redirected connections. Rewriting packets from servers to client is needed and the table of connections currently being rewritten should be maintained by each host. This may increase the service delay and the process overhead. Although DPR approach may perform dynamic and accurate load balancing, it increases network traffic of server hosts and CPU load to process lo ad information. In addition, naturally the disadvantage of RR-DNS is inherited. (2) ONE-IP ONE-IP[4] is another IP-level scheduling approach and is based on packet broadcasting and local filtering. A broadcast mechanism is used to send client packets to every server. Each machine implements a local filter so that every packets are processed by exactly one server. The architecture for this scheme is shown in Fig. 4.

8 When a request packet from a client arrives at the router, the router puts the packet on the server network as an Ethernet broadcast packet, and so packet is picked up by all the server machines[4,8]. A small filtering routine is added to each server s device driver to ensure that one machine accepts the packet. Each machine is assigned a unique ID number, and the filtering routine computes a hash value of the client IP address and compares it with the ID. If they do not match, the packet is discarded; otherwise, the server accepts the packet, and processes it as if it has received the packet through a normal IP routing mechanism. Since all the processing is based on the ghost IP, the reply packets are directly sent back to the client. Given n server machines, s0, s1,, s(n -1), and a packet from client IP address CA, a simple dispatching function is to compute k=ca mod n and select server k to process the packet. Since the scheme does not maintain any mapping table, the dispatcher is basically stateless. In order to make the determination of whether to forward a packet, stateless approach requires any information what can be found in the headers of each packet and does not rely on feedback from other machines regarding current load. The disadvantage is it can be applied to all operating systems because some operating systems will shutdown the network interface when detecting IP address collision, the local filtering also requires the modification of the kernel code of every server. In the broadcast-based dispatching scheme, broadcasting each incoming packet in the server LAN does not increase network traffic. However, a hash value needs to be computed for every ghost IP packet, which

9 increases the CPU load of each server. Compared to the communication delay, this computation overhead is negligible. Although this type of static load balancing allows low-cost implementations with fast dispatching, it may not perform dynamic and accurate load balancing. 3. Multicast-based Distributed LVS We propose the multicast-based distributed LVS, which can improve scalability and availability. This mechanism combines the centralized IP cluster and the distributed IP cluster. There are multiple Load Balancers, and incoming packets from router are multicast to Load Balancers. Service Load Balancer is selected by Packet Accept Load Balancing Algorithm. This figure follows the distributed IP cluster

10 mechanism, ONE-IP. After Service Load Balancer is selected, the rest of process follows the LVS mechanism. So, This figure follows the centralized IP cluster mechanism, LVS. (1) Single En try Point Image by the multicast-based multiple Load Balancers If router receives packets from client and transfers to the Load Balancers by multicast method, the Load Balancers should determine whether it accept the packet or not. There are several Packet Accept Load Balancing Algorithm. Once a Service Load Balancer is selected, future incoming packets for the same request must be directed to the same Load Balancer. The cluster system acts as follows: ( ) Client sends request to Apache Web server set by Virtual IP.

11 ( ) Router checks ARP table to found the Ethernet address of Load Balancer and multicasts to Ethernet Multicast corresponding Virtual IP address. ( ) Load Balancers accepts the multicast packets and decides to accept packet or not using Packet Accept load Balancing Algorithms. ( ) If Load Balancer decides to do packet service, Load Balancer forwards packets to the Real Server. If not so, packet is discarded. In our system, the whole nodes include Load Balancers and Real Servers share the Virtual IP, only one published IP. However, only the Load Balancers except the Real Servers share the Ethernet Multicast Address. That is, the NI C (Network Interface Card) address of the Load Balancers is set Virtual IP and Ethernet Multicast Address. So, if the router multicast the incoming packets, only Load Balancers are able to accept the IP packet from client. This configuration can be set by ifconfig command.

12 In addition, the ARP table of router should be fixed in Virtual IP and Ethernet multicast address statically by arp command. So, when the packet from client reaches the router, router may multicast the Virtual IP packet using the Ethernet Multicast Address. In this case, the above scheme requires a permanent ARP entry at the router. However, it would cause the router to overwrite the entry in its ARP cache, since there are the different ARP response messages from multiple Load Balancers. To overcome this problem, we deactivate the ARP response function with /proc command. In ONE-IP, another ghostip1 is used to solve this problem, but it is more difficult than ours. The main advantage of this mechanism is the availability and scalability improvement. Since there are multiple Load Balancers, though one of Load Balancers fails, the others can continuously service. So, the availability of cluster system may be increased very much. In addition, since the whole capacity of service is increased, the scalability may be increased. Now, we don t consider the modification of LVS. So the sub-cluster, which is controlled by each Load Balancer, is independent each other. This causes that some specific part depending on Packet Accept Load Balancing Algorithm doesn t serviced at all. However, it is more efficient than whole service stop. (2) Load balancing Algorithm among Load Balancers In our system, multiple Load Balancers behave as a single Load Balancer. If the job is not distributed to multiple Load Balancers fairly, some of Load Balancer may have overload and response time may be delayed.

13 So effective load balancing is an important issue of cluster system. There are two approaches depending on static or dynamic mechanism: Stateless and stateful load balancing policy. In stateless load balancing policy, load balancing is performed using a stateless routing function, e.g., a function that computes a hash value based on the source and destination IP address of the original packet. This mechanism is simple and fast, since it has not to maintain any additional information for the load balancing. However the disadvantage of this mechanism is that the load is not distributed fairly. On the other hand, the stateful load balancing policy may require more information than what is contained in the packets, for example, knowledge of load on other hosts. In this case, each rewriting host must maintain a routing table with an entry for each connection that is currently being handled by that host. As a result, this method can supports equivalent load distribution, but have a processing overhead and difficult to implement. To reduce CPU overhead of Load Balancer, we selected the stateless load balancing policy at first. Now, we propose three Packet Accept Load Balancing Algorithms. First method is to compute service Load Balancer = (the last number (1~255) of Client IP address) Mod (the total number of Load Balancers). Second method is efficiently to allocate the classes of IP addresses or a specific scope of IP address to the each Load Balancer. However, in advance recommending, the result shows this method is not suitable. Final method is the Round Robin service of the incoming packet. However, though incoming is fair, the CPU load of each Load Balancers may be different each other since the service time is not same.

14 To evaluate the efficiency of our proposal, at first we have analyzed a day of HTTP logs form a busy WWW server, EPA -HTTP and the caching log file of proxy server from A Distributed Testbed for National Information Provisioning project [12,13]. In EPA-HTTP log file, the logs were collected on August 30, 1995, a total of 24 hours. There were 47,748 total requests. However, the type of client address is two, IP address and Domain Name Address. To computation, we have extracted only the IP address type from log file. As a result, the total number of unique client IP was 567. We didn t consider the counter. In the caching log file of proxy server, site statistics files are from the five U.S. Super computer centers, and one at FIX-West. We have collected Top 20 client IP address from each site and the total number of unique client IP address was 30. Figure [5] shows the distribution of the client IP address. The load balancing method by the number of Load Balancers is reasonably fair by 56% and 44%, and 56.7% and 43.3%. However, the result shows that

15 when the number of client IP is low, the fairness is decreased. In addition, the allocation by the classes of IP addresses is not suitable obviously. 4. Prototype Implementations (1) System Architecture We have implemented our system on a cluster of Pentium 550 with Linux kernel connected via Fast Ethernet. ( ) Router To multicast incoming packet, ARP table of router should be set with Virtual IP and Ethernet Multicast Address. We can support it by arp command. To fix the arp table entry statically, we manually created an ARP mapping entry with arp s Virtual IP Ethernet Multicast Address. ( ) Virtual IP and Ethernet Multicast Address setting in whole hosts Ifconfig is used to configure the kernel-resident network interfaces. It is used to assign two IP addresses to the interface too. However, to deactivate ARP response function, we used the #echo 1 > /proc/sys/net/ipv4/conf/all/hidden command. To accept the multicasting packet, device driver should be able to perceive corresponding Ethernet

16 multicast address. Multicast join program can allow Ethernet Network card to accept the Multicast packet. ( ) Apache Web Sever If a host has several IP addresses, application should choose one of several IPs. In apache web server, this value is reported in configuration file. (2) Load Balancing in kernel layer Our Packet Accept Load Balancing Algorithm has to be implemented in kernel layer. However, several firewall commands support these mechanisms. Anyway, this should be proved by installing both LVS and firewall together, and seeing no confliction. 5. Conclusion and Future Work We evaluated existing technologies and proposed distributed LVS for providing multiple Load Balancers. A prototype on Linux kernel has been implemented. It shows the advantages of high scalability and availability by multiple Load Balancers. When we consider that the most important issue of cluster web server is scalability and availability, our proposal has very good advantages.. However, Packet Accept Load Balancing Algorithm is fast, but not fair. So this is our future work. In

17 addition, if one of Load Balancer is fail, clients can t access the sub-cluster of that Load Balancer anymore. Any efficient using method is needed also. References 1. Wensong Zhang, Shiyao jin and Qanyuan Wu, "Creating Linux Virtual Servers" LinuxExpo 1999 Conference 2. Wensong Zhang, Shiyao jin and Qanyuan Wu, "Linux Virtual Server for Scalable Network Services" Ottawa Linux Symposium 2000, July 19th~20nd, Wensong Zhang, Shiyao jin and Qanyuan Wu, "Linux Virtual Servers : Server Clustering for Scalable Network Services" The 2th Linux Revolution Om P. Damani and P. Emerald Chung and Yennun Huang and Chandra Kintala and Yi-Min Wang, ONE-IP: Techniques for hosting a service on a cluster of machines", Computer networks and ISDN Systems, volume 29, Sep, Azer Bestavros and Mark Crovella and Jun Liu and David Martin, "Distributed Packet Rewriting and its Application to Scalable Server Architectures", in proceeding of ICNP 98: The 6th IEEE International Conference on Network Protocols, (Austin, TX), October 1998

18 6. Luis Aversa and Azer Bestavros, Load Balancing a Cluster of Web Servers using Distributed Packet Rewriting, Technical Report, CS Department, Boston University, Number , January Daniel Anderson, Tao Yang, and Oscar H. Ibarra, Towards a Scalable Distributed WWW Server on workstation clusters, Proc. Of 10th IEEE Intl. Symp. Of Parallel Processing (IPPS 96), pp , April J. Mogul, R. Rashid, and M. Accetta, The Packet Filter: An Efficient Mechanism for user-level Network Code. In Proceedings of SOSP 87: The 11th ACM Symposium on operating Systems Principles, Eric Anderson, Dave Patterson, and Eric Brewer, The Magicroter: an Application of Fast packet Interposing (May 1996) Cisco System, Cisco Local Director (1998), 11. Wensong Zhang, Linux Virtual Server Project, 12. A Distributed Testbed for Natinoal Information Provisioning, web site, 13. EPA -HTTP, web site, -HTTP.html

Load Balancing a Cluster of Web Servers

Load Balancing a Cluster of Web Servers Load Balancing a Cluster of Web Servers Using Distributed Packet Rewriting Luis Aversa Laversa@cs.bu.edu Azer Bestavros Bestavros@cs.bu.edu Computer Science Department Boston University Abstract We present

More information

Load Balancing a Cluster of Web Servers

Load Balancing a Cluster of Web Servers Load Balancing a Cluster of Web Servers Using Distributed Packet Rewriting Luis Aversa Laversa@cs.bu.edu Azer Bestavros Bestavros@cs.bu.edu Computer Science Department Boston University Abstract In this

More information

Introduction. Linux Virtual Server for Scalable Network Services. Linux Virtual Server. 3-tier architecture of LVS. Virtual Server via NAT

Introduction. Linux Virtual Server for Scalable Network Services. Linux Virtual Server. 3-tier architecture of LVS. Virtual Server via NAT Linux Virtual Server for Scalable Network Services Wensong Zhang wensong@gnuchina.org Ottawa Linux Symposium 2000 July 22th, 2000 1 Introduction Explosive growth of the Internet The requirements for servers

More information

Performance Assessment of High Availability Clustered Computing using LVS-NAT

Performance Assessment of High Availability Clustered Computing using LVS-NAT Performance Assessment of High Availability Clustered Computing using LVS-NAT *Muhammad Kashif Shaikh, **Muzammil Ahmad Khan and ***Mumtaz-ul-Imam Abstract High availability cluster computing environment

More information

Distributed Packet Rewriting and its Application to Scalable Server Architectures

Distributed Packet Rewriting and its Application to Scalable Server Architectures Distributed Packet Rewriting and its Application to Scalable Server Architectures Azer Bestavros Mark Crovella Jun Liu David Martin Computer Science Department Dept of Math and CS Boston University University

More information

The Three-level Approaches for Differentiated Service in Clustering Web Server

The Three-level Approaches for Differentiated Service in Clustering Web Server The Three-level Approaches for Differentiated Service in Clustering Web Server Myung-Sub Lee and Chang-Hyeon Park School of Computer Science and Electrical Engineering, Yeungnam University Kyungsan, Kyungbuk

More information

UNIVERSITY OF OSLO Department of Informatics. Performance Measurement of Web Services Linux Virtual Server. Muhammad Ashfaq Oslo University College

UNIVERSITY OF OSLO Department of Informatics. Performance Measurement of Web Services Linux Virtual Server. Muhammad Ashfaq Oslo University College UNIVERSITY OF OSLO Department of Informatics Performance Measurement of Web Services Linux Virtual Server Muhammad Ashfaq Oslo University College May 19, 2009 Performance Measurement of Web Services Linux

More information

High Performance Cluster Support for NLB on Window

High Performance Cluster Support for NLB on Window High Performance Cluster Support for NLB on Window [1]Arvind Rathi, [2] Kirti, [3] Neelam [1]M.Tech Student, Department of CSE, GITM, Gurgaon Haryana (India) arvindrathi88@gmail.com [2]Asst. Professor,

More information

Scalable Linux Clusters with LVS

Scalable Linux Clusters with LVS Scalable Linux Clusters with LVS Considerations and Implementation, Part I Eric Searcy Tag1 Consulting, Inc. emsearcy@tag1consulting.com April 2008 Abstract Whether you are perusing mailing lists or reading

More information

PEGASUS: Competitive load balancing using inetd

PEGASUS: Competitive load balancing using inetd PEGASUS: Competitive load balancing using inetd George Oikonomou 1 Vassilios Karakoidas 2 Theodoros Apostolopoulos 1 1 Department of Informatics Athens University of Economics and Business {g.oikonomou,tca}@aueb.gr

More information

Content-Aware Load Balancing using Direct Routing for VOD Streaming Service

Content-Aware Load Balancing using Direct Routing for VOD Streaming Service Content-Aware Load Balancing using Direct Routing for VOD Streaming Service Young-Hwan Woo, Jin-Wook Chung, Seok-soo Kim Dept. of Computer & Information System, Geo-chang Provincial College, Korea School

More information

LinuxDirector: A Connection Director for Scalable Internet Services

LinuxDirector: A Connection Director for Scalable Internet Services LinuxDirector: A Connection Director for Scalable Internet Services Wensong Zhang, Shiyao Jin, Quanyuan Wu National Laboratory for Parallel & Distributed Processing Changsha, Hunan 410073, China wensong@linuxvirtualserver.org

More information

Building a Highly Available and Scalable Web Farm

Building a Highly Available and Scalable Web Farm Page 1 of 10 MSDN Home > MSDN Library > Deployment Rate this page: 10 users 4.9 out of 5 Building a Highly Available and Scalable Web Farm Duwamish Online Paul Johns and Aaron Ching Microsoft Developer

More information

A Novel Adaptive Distributed Load Balancing Strategy for Cluster *

A Novel Adaptive Distributed Load Balancing Strategy for Cluster * A Novel Adaptive Distributed Balancing Strategy for Cluster * Hai Jin, Bin Cheng, Shengli Li Cluster and Grid Computing Lab Huazhong University of Science & Technology, Wuhan, China {hjin,showersky}@hust.edu.cn

More information

A Low Cost Two-tier Architecture Model Implementation for High Availability Clusters For Application Load Balancing

A Low Cost Two-tier Architecture Model Implementation for High Availability Clusters For Application Load Balancing A Low Cost Two-tier Architecture Model Implementation for High Availability Clusters For Application Load Balancing A B M Moniruzzaman 1, Syed Akther Hossain IEEE Department of Computer Science and Engineering

More information

Linux Virtual Server for Scalable Network Services

Linux Virtual Server for Scalable Network Services Linux Virtual Server for Scalable Network Services Wensong Zhang National Laboratory for Parallel & Distributed Processing Changsha, Hunan 410073, China wensong@linuxvirtualserver.org, http://www.linuxvirtualserver.org/

More information

A Low Cost Two-Tier Architecture Model For High Availability Clusters Application Load Balancing

A Low Cost Two-Tier Architecture Model For High Availability Clusters Application Load Balancing A Low Cost Two-Tier Architecture Model For High Availability Clusters Application Load Balancing A B M Moniruzzaman, StudentMember, IEEE Department of Computer Science and Engineering Daffodil International

More information

Implementation, Simulation of Linux Virtual Server in ns-2

Implementation, Simulation of Linux Virtual Server in ns-2 Implementation, Simulation of Linux Virtual Server in ns-2 CMPT 885 Special Topics: High Performance Networks Project Final Report Yuzhuang Hu yhu1@cs.sfu.ca ABSTRACT LVS(Linux Virtual Server) provides

More information

Protecting and controlling Virtual LANs by Linux router-firewall

Protecting and controlling Virtual LANs by Linux router-firewall Protecting and controlling Virtual LANs by Linux router-firewall Tihomir Katić Mile Šikić Krešimir Šikić Faculty of Electrical Engineering and Computing University of Zagreb Unska 3, HR 10000 Zagreb, Croatia

More information

A Content Aware Scheduling System for Network Services in Linux Clusters 1

A Content Aware Scheduling System for Network Services in Linux Clusters 1 A Content Aware Scheduling System for Network Services in Linux Clusters 1 Yijun Lu, Hai Jin, Hong Jiang* and Zongfen Han Huazhong University of Science and Technology, Wuhan, Hubei, 430074, China yijlu@cse.unl.edu

More information

Dynamic Load Balancing for Web Clusters

Dynamic Load Balancing for Web Clusters Dynamic Load Balancing for Web Clusters M. Adamou 1, D. Anthomelidis 1, K. Antonis 2, J. Garofalakis 2, P. Spirakis 2 1. Systems Design Research Lab (SDRL), Dept. of Computer & Information Science, Univ.

More information

Purpose-Built Load Balancing The Advantages of Coyote Point Equalizer over Software-based Solutions

Purpose-Built Load Balancing The Advantages of Coyote Point Equalizer over Software-based Solutions Purpose-Built Load Balancing The Advantages of Coyote Point Equalizer over Software-based Solutions Abstract Coyote Point Equalizer appliances deliver traffic management solutions that provide high availability,

More information

Configuring Network Address Translation (NAT)

Configuring Network Address Translation (NAT) 8 Configuring Network Address Translation (NAT) Contents Overview...................................................... 8-3 Translating Between an Inside and an Outside Network........... 8-3 Local and

More information

A High Performance System Prototype for Large-scale SMTP Services

A High Performance System Prototype for Large-scale SMTP Services A High Performance System Prototype for Large-scale SMTP Services Sethalat Rodhetbhai g4165238@ku.ac.th Yuen Poovarawan yuen@ku.ac.th Department of Computer Engineering Kasetsart University Bangkok, Thailand

More information

HyLARD: A Hybrid Locality-Aware Request Distribution Policy in Cluster-based Web Servers

HyLARD: A Hybrid Locality-Aware Request Distribution Policy in Cluster-based Web Servers TANET2007 臺 灣 網 際 網 路 研 討 會 論 文 集 二 HyLARD: A Hybrid Locality-Aware Request Distribution Policy in Cluster-based Web Servers Shang-Yi Zhuang, Mei-Ling Chiang Department of Information Management National

More information

Avaya P333R-LB. Load Balancing Stackable Switch. Load Balancing Application Guide

Avaya P333R-LB. Load Balancing Stackable Switch. Load Balancing Application Guide Load Balancing Stackable Switch Load Balancing Application Guide May 2001 Table of Contents: Section 1: Introduction Section 2: Application 1 Server Load Balancing Section 3: Application 2 Firewall Load

More information

Internet Security Firewalls

Internet Security Firewalls Overview Internet Security Firewalls Ozalp Babaoglu! Exo-structures " Firewalls " Virtual Private Networks! Cryptography-based technologies " IPSec " Secure Socket Layer ALMA MATER STUDIORUM UNIVERSITA

More information

Creating Web Farms with Linux (Linux High Availability and Scalability)

Creating Web Farms with Linux (Linux High Availability and Scalability) Creating Web Farms with Linux (Linux High Availability and Scalability) Horms (Simon Horman) horms@verge.net.au December 2001 For Presentation in Tokyo, Japan http://verge.net.au/linux/has/ http://ultramonkey.org/

More information

Chapter 7. Address Translation

Chapter 7. Address Translation Chapter 7. Address Translation This chapter describes NetDefendOS address translation capabilities. Dynamic Network Address Translation, page 204 NAT Pools, page 207 Static Address Translation, page 210

More information

Remaining Capacity Based Load Balancing Architecture for Heterogeneous Web Server System

Remaining Capacity Based Load Balancing Architecture for Heterogeneous Web Server System Remaining Capacity Based Load Balancing Architecture for Heterogeneous Web Server System Tsang-Long Pao Dept. Computer Science and Engineering Tatung University Taipei, ROC Jian-Bo Chen Dept. Computer

More information

Creating Web Farms with Linux (Linux High Availability and Scalability)

Creating Web Farms with Linux (Linux High Availability and Scalability) Creating Web Farms with Linux (Linux High Availability and Scalability) Horms (Simon Horman) horms@verge.net.au October 2000 http://verge.net.au/linux/has/ http://ultramonkey.sourceforge.net/ Introduction:

More information

Availability Digest. www.availabilitydigest.com. Redundant Load Balancing for High Availability July 2013

Availability Digest. www.availabilitydigest.com. Redundant Load Balancing for High Availability July 2013 the Availability Digest Redundant Load Balancing for High Availability July 2013 A large data center can comprise hundreds or thousands of servers. These servers must not only be interconnected, but they

More information

DB2 Connect for NT and the Microsoft Windows NT Load Balancing Service

DB2 Connect for NT and the Microsoft Windows NT Load Balancing Service DB2 Connect for NT and the Microsoft Windows NT Load Balancing Service Achieving Scalability and High Availability Abstract DB2 Connect Enterprise Edition for Windows NT provides fast and robust connectivity

More information

ZEN LOAD BALANCER EE v3.04 DATASHEET The Load Balancing made easy

ZEN LOAD BALANCER EE v3.04 DATASHEET The Load Balancing made easy ZEN LOAD BALANCER EE v3.04 DATASHEET The Load Balancing made easy OVERVIEW The global communication and the continuous growth of services provided through the Internet or local infrastructure require to

More information

Internet Protocol: IP packet headers. vendredi 18 octobre 13

Internet Protocol: IP packet headers. vendredi 18 octobre 13 Internet Protocol: IP packet headers 1 IPv4 header V L TOS Total Length Identification F Frag TTL Proto Checksum Options Source address Destination address Data (payload) Padding V: Version (IPv4 ; IPv6)

More information

ICS 351: Today's plan. IP addresses Network Address Translation Dynamic Host Configuration Protocol Small Office / Home Office configuration

ICS 351: Today's plan. IP addresses Network Address Translation Dynamic Host Configuration Protocol Small Office / Home Office configuration ICS 351: Today's plan IP addresses Network Address Translation Dynamic Host Configuration Protocol Small Office / Home Office configuration IP address exhaustion IPv4 addresses are 32 bits long so there

More information

Optimization of Cluster Web Server Scheduling from Site Access Statistics

Optimization of Cluster Web Server Scheduling from Site Access Statistics Optimization of Cluster Web Server Scheduling from Site Access Statistics Nartpong Ampornaramveth, Surasak Sanguanpong Faculty of Computer Engineering, Kasetsart University, Bangkhen Bangkok, Thailand

More information

SE 4C03 Winter 2005 Firewall Design Principles. By: Kirk Crane

SE 4C03 Winter 2005 Firewall Design Principles. By: Kirk Crane SE 4C03 Winter 2005 Firewall Design Principles By: Kirk Crane Firewall Design Principles By: Kirk Crane 9810533 Introduction Every network has a security policy that will specify what traffic is allowed

More information

Virtual private network. Network security protocols VPN VPN. Instead of a dedicated data link Packets securely sent over a shared network Internet VPN

Virtual private network. Network security protocols VPN VPN. Instead of a dedicated data link Packets securely sent over a shared network Internet VPN Virtual private network Network security protocols COMP347 2006 Len Hamey Instead of a dedicated data link Packets securely sent over a shared network Internet VPN Public internet Security protocol encrypts

More information

We will give some overview of firewalls. Figure 1 explains the position of a firewall. Figure 1: A Firewall

We will give some overview of firewalls. Figure 1 explains the position of a firewall. Figure 1: A Firewall Chapter 10 Firewall Firewalls are devices used to protect a local network from network based security threats while at the same time affording access to the wide area network and the internet. Basically,

More information

1 Data information is sent onto the network cable using which of the following? A Communication protocol B Data packet

1 Data information is sent onto the network cable using which of the following? A Communication protocol B Data packet Review questions 1 Data information is sent onto the network cable using which of the following? A Communication protocol B Data packet C Media access method D Packages 2 To which TCP/IP architecture layer

More information

Load Balancing and Sessions. C. Kopparapu, Load Balancing Servers, Firewalls and Caches. Wiley, 2002.

Load Balancing and Sessions. C. Kopparapu, Load Balancing Servers, Firewalls and Caches. Wiley, 2002. Load Balancing and Sessions C. Kopparapu, Load Balancing Servers, Firewalls and Caches. Wiley, 2002. Scalability multiple servers Availability server fails Manageability Goals do not route to it take servers

More information

CheckPoint Software Technologies LTD. How to Configure Firewall-1 With Connect Control

CheckPoint Software Technologies LTD. How to Configure Firewall-1 With Connect Control CheckPoint Software Technologies LTD. How to Configure Firewall-1 With Connect Control (Load-Balance across multiple servers) Event: Partner Exchange Conference Date: October 10, 1999 Revision 1.0 Author:

More information

Chapter 1 Personal Computer Hardware------------------------------------------------ 7 hours

Chapter 1 Personal Computer Hardware------------------------------------------------ 7 hours Essential Curriculum Networking Essentials Total Hours: 244 Cisco Discovery 1: Networking for Home and Small Businesses 81.5 hours teaching time Chapter 1 Personal Computer Hardware------------------------------------------------

More information

Firewalls. Ahmad Almulhem March 10, 2012

Firewalls. Ahmad Almulhem March 10, 2012 Firewalls Ahmad Almulhem March 10, 2012 1 Outline Firewalls The Need for Firewalls Firewall Characteristics Types of Firewalls Firewall Basing Firewall Configurations Firewall Policies and Anomalies 2

More information

Building Secure Network Infrastructure For LANs

Building Secure Network Infrastructure For LANs Building Secure Network Infrastructure For LANs Yeung, K., Hau; and Leung, T., Chuen Abstract This paper discusses the building of secure network infrastructure for local area networks. It first gives

More information

How To - Configure Virtual Host using FQDN How To Configure Virtual Host using FQDN

How To - Configure Virtual Host using FQDN How To Configure Virtual Host using FQDN How To - Configure Virtual Host using FQDN How To Configure Virtual Host using FQDN Applicable Version: 10.6.2 onwards Overview Virtual host implementation is based on the Destination NAT concept. Virtual

More information

UPPER LAYER SWITCHING

UPPER LAYER SWITCHING 52-20-40 DATA COMMUNICATIONS MANAGEMENT UPPER LAYER SWITCHING Gilbert Held INSIDE Upper Layer Operations; Address Translation; Layer 3 Switching; Layer 4 Switching OVERVIEW The first series of LAN switches

More information

OpenFlow Based Load Balancing

OpenFlow Based Load Balancing OpenFlow Based Load Balancing Hardeep Uppal and Dane Brandon University of Washington CSE561: Networking Project Report Abstract: In today s high-traffic internet, it is often desirable to have multiple

More information

Linux Network Security

Linux Network Security Linux Network Security Course ID SEC220 Course Description This extremely popular class focuses on network security, and makes an excellent companion class to the GL550: Host Security course. Protocols

More information

Network Security TCP/IP Refresher

Network Security TCP/IP Refresher Network Security TCP/IP Refresher What you (at least) need to know about networking! Dr. David Barrera Network Security HS 2014 Outline Network Reference Models Local Area Networks Internet Protocol (IP)

More information

The Design and Implementation of Content Switch On IXP12EB

The Design and Implementation of Content Switch On IXP12EB The Design and Implementation of Content Switch On IXP12EB Thesis Proposal by Longhua Li Computer Science Department University of Colorado at Colorado Springs 5/15/2001 Approved by: Dr. Edward Chow (Advisor)

More information

Stateful Inspection Technology

Stateful Inspection Technology Stateful Inspection Technology Security Requirements TECH NOTE In order to provide robust security, a firewall must track and control the flow of communication passing through it. To reach control decisions

More information

CSE331: Introduction to Networks and Security. Lecture 12 Fall 2006

CSE331: Introduction to Networks and Security. Lecture 12 Fall 2006 CSE331: Introduction to Networks and Security Lecture 12 Fall 2006 Announcements Midterm I will be held Friday, Oct. 6th. True/False Multiple Choice Calculation Short answer Short essay Project 2 is on

More information

Internet Security Firewalls

Internet Security Firewalls Internet Security Firewalls Ozalp Babaoglu ALMA MATER STUDIORUM UNIVERSITA DI BOLOGNA Overview Exo-structures Firewalls Virtual Private Networks Cryptography-based technologies IPSec Secure Socket Layer

More information

19531 - Telematics. 14th Tutorial - Proxies, Firewalls, P2P

19531 - Telematics. 14th Tutorial - Proxies, Firewalls, P2P 19531 - Telematics 14th Tutorial - Proxies, Firewalls, P2P Bastian Blywis Department of Mathematics and Computer Science Institute of Computer Science 10. February, 2011 Institute of Computer Science Telematics

More information

Lab 5 Explicit Proxy Performance, Load Balancing & Redundancy

Lab 5 Explicit Proxy Performance, Load Balancing & Redundancy Lab 5 Explicit Proxy Performance, Load Balancing & Redundancy Objectives The purpose of this lab is to demonstrate both high availability and performance using virtual IPs coupled with DNS round robin

More information

A Heterogeneous Internetworking Model with Enhanced Management and Security Functions

A Heterogeneous Internetworking Model with Enhanced Management and Security Functions Session 1626 A Heterogeneous Internetworking Model with Enhanced Management and Security Functions Youlu Zheng Computer Science Department University of Montana Yan Zhu Sybase, Inc. To demonstrate how

More information

Firewalls P+S Linux Router & Firewall 2013

Firewalls P+S Linux Router & Firewall 2013 Firewalls P+S Linux Router & Firewall 2013 Firewall Techniques What is a firewall? A firewall is a hardware or software device which is configured to permit, deny, or proxy data through a computer network

More information

CS 188/219. Scalable Internet Services Andrew Mutz October 8, 2015

CS 188/219. Scalable Internet Services Andrew Mutz October 8, 2015 CS 188/219 Scalable Internet Services Andrew Mutz October 8, 2015 For Today About PTEs Empty spots were given out If more spots open up, I will issue more PTEs You must have a group by today. More detail

More information

Chapter 14: Distributed Operating Systems

Chapter 14: Distributed Operating Systems Chapter 14: Distributed Operating Systems Chapter 14: Distributed Operating Systems Motivation Types of Distributed Operating Systems Network Structure Network Topology Communication Structure Communication

More information

SNMP and Web-based Load Cluster Management System

SNMP and Web-based Load Cluster Management System and Web-based Load Cluster Management System Myungsup Kim and J. Won-Ki Hong Distributed Processing & Network Management Lab. Dept. of Computer Science and Engineering, Pohang Korea Tel: +82-54-279-5654

More information

Stateful Firewalls. Hank and Foo

Stateful Firewalls. Hank and Foo Stateful Firewalls Hank and Foo 1 Types of firewalls Packet filter (stateless) Proxy firewalls Stateful inspection Deep packet inspection 2 Packet filter (Access Control Lists) Treats each packet in isolation

More information

Chapter 11 Cloud Application Development

Chapter 11 Cloud Application Development Chapter 11 Cloud Application Development Contents Motivation. Connecting clients to instances through firewalls. Chapter 10 2 Motivation Some of the questions of interest to application developers: How

More information

Agenda. Distributed System Structures. Why Distributed Systems? Motivation

Agenda. Distributed System Structures. Why Distributed Systems? Motivation Agenda Distributed System Structures CSCI 444/544 Operating Systems Fall 2008 Motivation Network structure Fundamental network services Sockets and ports Client/server model Remote Procedure Call (RPC)

More information

International Journal of Scientific & Engineering Research, Volume 4, Issue 8, August-2013 1300 ISSN 2229-5518

International Journal of Scientific & Engineering Research, Volume 4, Issue 8, August-2013 1300 ISSN 2229-5518 International Journal of Scientific & Engineering Research, Volume 4, Issue 8, August-2013 1300 Efficient Packet Filtering for Stateful Firewall using the Geometric Efficient Matching Algorithm. Shriya.A.

More information

CS514: Intermediate Course in Computer Systems

CS514: Intermediate Course in Computer Systems : Intermediate Course in Computer Systems Lecture 7: Sept. 19, 2003 Load Balancing Options Sources Lots of graphics and product description courtesy F5 website (www.f5.com) I believe F5 is market leader

More information

AS/400e. TCP/IP routing and workload balancing

AS/400e. TCP/IP routing and workload balancing AS/400e TCP/IP routing and workload balancing AS/400e TCP/IP routing and workload balancing Copyright International Business Machines Corporation 2000. All rights reserved. US Government Users Restricted

More information

Module 6. Internetworking. Version 2 CSE IIT, Kharagpur

Module 6. Internetworking. Version 2 CSE IIT, Kharagpur Module 6 Internetworking Lesson 2 Internet Protocol (IP) Specific Instructional Objectives At the end of this lesson, the students will be able to: Explain the relationship between TCP/IP and OSI model

More information

Module 15: Network Structures

Module 15: Network Structures Module 15: Network Structures Background Topology Network Types Communication Communication Protocol Robustness Design Strategies 15.1 A Distributed System 15.2 Motivation Resource sharing sharing and

More information

co Characterizing and Tracing Packet Floods Using Cisco R

co Characterizing and Tracing Packet Floods Using Cisco R co Characterizing and Tracing Packet Floods Using Cisco R Table of Contents Characterizing and Tracing Packet Floods Using Cisco Routers...1 Introduction...1 Before You Begin...1 Conventions...1 Prerequisites...1

More information

Overview: Load Balancing with the MNLB Feature Set for LocalDirector

Overview: Load Balancing with the MNLB Feature Set for LocalDirector CHAPTER 1 Overview: Load Balancing with the MNLB Feature Set for LocalDirector This chapter provides a conceptual overview of load balancing and introduces Cisco s MultiNode Load Balancing (MNLB) Feature

More information

Assignment 6: Internetworking Due October 17/18, 2012

Assignment 6: Internetworking Due October 17/18, 2012 Assignment 6: Internetworking Due October 17/18, 2012 Our topic this week will be the notion of internetworking in general and IP, the Internet Protocol, in particular. IP is the foundation of the Internet

More information

Note on Remote Laboratory Access: A Networking Perspective

Note on Remote Laboratory Access: A Networking Perspective Note on Remote Laboratory Access: A Networking Perspective Alexander A. Kist Faculty of Engineering and Surveying University of Southern Queensland Toowoomba, Queensland 4350 Australia Email: kist@ieee.org

More information

Introduction to LAN/WAN. Network Layer (part II)

Introduction to LAN/WAN. Network Layer (part II) Introduction to LAN/WAN Network Layer (part II) Topics The Network Layer Introduction Routing (5.2) The Internet (5.5) IP, IP addresses ARP (5.5.4) OSPF (5.5.5) BGP (5.5.6) Congestion Control (5.3) Internetworking

More information

Load Balancing Web Proxies Load Balancing Web Filters Load Balancing Web Gateways. Deployment Guide

Load Balancing Web Proxies Load Balancing Web Filters Load Balancing Web Gateways. Deployment Guide Load Balancing Web Proxies Load Balancing Web Filters Load Balancing Web Gateways Deployment Guide rev. 1.4.9 Copyright 2015 Loadbalancer.org, Inc. 1 Table of Contents About this Guide... 3 Appliances

More information

ΕΠΛ 674: Εργαστήριο 5 Firewalls

ΕΠΛ 674: Εργαστήριο 5 Firewalls ΕΠΛ 674: Εργαστήριο 5 Firewalls Παύλος Αντωνίου Εαρινό Εξάμηνο 2011 Department of Computer Science Firewalls A firewall is hardware, software, or a combination of both that is used to prevent unauthorized

More information

packet retransmitting based on dynamic route table technology, as shown in fig. 2 and 3.

packet retransmitting based on dynamic route table technology, as shown in fig. 2 and 3. Implementation of an Emulation Environment for Large Scale Network Security Experiments Cui Yimin, Liu Li, Jin Qi, Kuang Xiaohui National Key Laboratory of Science and Technology on Information System

More information

8 steps to protect your Cisco router

8 steps to protect your Cisco router 8 steps to protect your Cisco router Daniel B. Cid daniel@underlinux.com.br Network security is a completely changing area; new devices like IDS (Intrusion Detection systems), IPS (Intrusion Prevention

More information

A Low Cost Two-Tier Architecture Model for High Availability Clusters Application Load Balancing

A Low Cost Two-Tier Architecture Model for High Availability Clusters Application Load Balancing , pp.89-98 http://dx.doi.org/10.14257/ijgdc.2014.7.1.09 A Low Cost Two-Tier Architecture Model for High Availability Clusters Application Load Balancing A. B. M. Moniruzzaman 1 and Syed Akther Hossain

More information

Proxy Server, Network Address Translator, Firewall. Proxy Server

Proxy Server, Network Address Translator, Firewall. Proxy Server Proxy Server, Network Address Translator, Firewall 1 Proxy Server 2 1 Introduction What is a proxy server? Acts on behalf of other clients, and presents requests from other clients to a server. Acts as

More information

Chapter 16: Distributed Operating Systems

Chapter 16: Distributed Operating Systems Module 16: Distributed ib System Structure, Silberschatz, Galvin and Gagne 2009 Chapter 16: Distributed Operating Systems Motivation Types of Network-Based Operating Systems Network Structure Network Topology

More information

Server Traffic Management. Jeff Chase Duke University, Department of Computer Science CPS 212: Distributed Information Systems

Server Traffic Management. Jeff Chase Duke University, Department of Computer Science CPS 212: Distributed Information Systems Server Traffic Management Jeff Chase Duke University, Department of Computer Science CPS 212: Distributed Information Systems The Server Selection Problem server array A server farm B Which server? Which

More information

LOAD BALANCING TECHNIQUES FOR RELEASE 11i AND RELEASE 12 E-BUSINESS ENVIRONMENTS

LOAD BALANCING TECHNIQUES FOR RELEASE 11i AND RELEASE 12 E-BUSINESS ENVIRONMENTS LOAD BALANCING TECHNIQUES FOR RELEASE 11i AND RELEASE 12 E-BUSINESS ENVIRONMENTS Venkat Perumal IT Convergence Introduction Any application server based on a certain CPU, memory and other configurations

More information

Comparison of Load Balancing Strategies on Cluster-based Web Servers

Comparison of Load Balancing Strategies on Cluster-based Web Servers Comparison of Load Balancing Strategies on Cluster-based Web Servers Yong Meng TEO Department of Computer Science National University of Singapore 3 Science Drive 2 Singapore 117543 email: teoym@comp.nus.edu.sg

More information

ZEN LOAD BALANCER EE v3.02 DATASHEET The Load Balancing made easy

ZEN LOAD BALANCER EE v3.02 DATASHEET The Load Balancing made easy ZEN LOAD BALANCER EE v3.02 DATASHEET The Load Balancing made easy OVERVIEW The global communication and the continuous growth of services provided through the Internet or local infrastructure require to

More information

Operating System Concepts. Operating System 資 訊 工 程 學 系 袁 賢 銘 老 師

Operating System Concepts. Operating System 資 訊 工 程 學 系 袁 賢 銘 老 師 Lecture 7: Distributed Operating Systems A Distributed System 7.2 Resource sharing Motivation sharing and printing files at remote sites processing information in a distributed database using remote specialized

More information

Load Balancing McAfee Web Gateway. Deployment Guide

Load Balancing McAfee Web Gateway. Deployment Guide Load Balancing McAfee Web Gateway Deployment Guide rev. 1.1.4 Copyright 2015 Loadbalancer.org, Inc. 1 Table of Contents About this Guide... 3 Loadbalancer.org Appliances Supported...3 Loadbalancer.org

More information

Essential Curriculum Computer Networking 1. PC Systems Fundamentals 35 hours teaching time

Essential Curriculum Computer Networking 1. PC Systems Fundamentals 35 hours teaching time Essential Curriculum Computer Networking 1 PC Systems Fundamentals 35 hours teaching time Part 1----------------------------------------------------------------------------------------- 2.3 hours Develop

More information

Campus IPv6 connection Campus IPv6 deployment

Campus IPv6 connection Campus IPv6 deployment Campus IPv6 connection Campus IPv6 deployment Campus Address allocation, Topology Issues János Mohácsi NIIF/HUNGARNET Copy Rights This slide set is the ownership of the 6DISS project via its partners The

More information

Security threats and network. Software firewall. Hardware firewall. Firewalls

Security threats and network. Software firewall. Hardware firewall. Firewalls Security threats and network As we have already discussed, many serious security threats come from the networks; Firewalls The firewalls implement hardware or software solutions based on the control of

More information

AN EFFICIENT LOAD BALANCING ALGORITHM FOR A DISTRIBUTED COMPUTER SYSTEM. Dr. T.Ravichandran, B.E (ECE), M.E(CSE), Ph.D., MISTE.,

AN EFFICIENT LOAD BALANCING ALGORITHM FOR A DISTRIBUTED COMPUTER SYSTEM. Dr. T.Ravichandran, B.E (ECE), M.E(CSE), Ph.D., MISTE., AN EFFICIENT LOAD BALANCING ALGORITHM FOR A DISTRIBUTED COMPUTER SYSTEM K.Kungumaraj, M.Sc., B.L.I.S., M.Phil., Research Scholar, Principal, Karpagam University, Hindusthan Institute of Technology, Coimbatore

More information

Load Balancing Voice Applications with Piranha 1

Load Balancing Voice Applications with Piranha 1 Load Balancing Voice Applications with Piranha 1 Mustapha Hadim & Pierre Manneback Faculté Polytechnique de Mons - INFO Rue de Houdain 9, 7000 Mons Belgium Tel: 00 32 65 37 40 58 Fax: 00 32 65 37 45 00

More information

Understanding Slow Start

Understanding Slow Start Chapter 1 Load Balancing 57 Understanding Slow Start When you configure a NetScaler to use a metric-based LB method such as Least Connections, Least Response Time, Least Bandwidth, Least Packets, or Custom

More information

Linux firewall. Need of firewall Single connection between network Allows restricted traffic between networks Denies un authorized users

Linux firewall. Need of firewall Single connection between network Allows restricted traffic between networks Denies un authorized users Linux firewall Need of firewall Single connection between network Allows restricted traffic between networks Denies un authorized users Linux firewall Linux is a open source operating system and any firewall

More information

Firewall Introduction Several Types of Firewall. Cisco PIX Firewall

Firewall Introduction Several Types of Firewall. Cisco PIX Firewall Firewall Introduction Several Types of Firewall. Cisco PIX Firewall What is a Firewall? Non-computer industries: a wall that controls the spreading of a fire. Networks: a designed device that controls

More information

Efficient Addressing. Outline. Addressing Subnetting Supernetting CS 640 1

Efficient Addressing. Outline. Addressing Subnetting Supernetting CS 640 1 Efficient Addressing Outline Addressing Subnetting Supernetting CS 640 1 IPV4 Global Addresses Properties IPv4 uses 32 bit address space globally unique hierarchical: network + host 7 24 Dot Notation 10.3.2.4

More information

Course Overview: Learn the essential skills needed to set up, configure, support, and troubleshoot your TCP/IP-based network.

Course Overview: Learn the essential skills needed to set up, configure, support, and troubleshoot your TCP/IP-based network. Course Name: TCP/IP Networking Course Overview: Learn the essential skills needed to set up, configure, support, and troubleshoot your TCP/IP-based network. TCP/IP is the globally accepted group of protocols

More information

High-Performance IP Service Node with Layer 4 to 7 Packet Processing Features

High-Performance IP Service Node with Layer 4 to 7 Packet Processing Features UDC 621.395.31:681.3 High-Performance IP Service Node with Layer 4 to 7 Packet Processing Features VTsuneo Katsuyama VAkira Hakata VMasafumi Katoh VAkira Takeyama (Manuscript received February 27, 2001)

More information