Load balancing deal with the techniques involved on using multiple systems to deal with high demands, balancing the load between those multiple systems. Questions deal with networking and server load balancing, using dedicated hardware or not.

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48
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3answers
26k views

What is the difference between Load Balancer and Reverse Proxy?

I'm not clear about the difference between Load Balancer and Reverse Proxy. They both seems having same behavior: distributing incoming requests to backend servers.
42
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5answers
43k views

Does each server behind a load balancer need their own SSL certificate?

If you have 5 web servers behind a load balancer (such as haproxy) and they are serving up content for the same domain, do you need SSL certificates for all the servers, or can you use the same ...
36
votes
16answers
37k views

Is Round-Robin DNS “good enough” for load balancing static content?

We have a set of shared, static content that we serve up between our websites at http://sstatic.net. Unfortunately, this content is not currently load balanced at all -- it's served from a single ...
28
votes
5answers
23k views

How can I remove balanced node from haproxy via command line?

I have haproxy running as my load-balancer and from the stats web interface that comes with haproxy, I can put a web server into maintenance mode (and bring it back out again) - which is great! ...
25
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14answers
3k views

Load-balancer options [closed]

I am looking at a number of possible options for load-balancing. So far, I am constrained to the following options: DNS server load-balancer, balancing to a cluster of tomcat servers, with ...
21
votes
3answers
9k views

How can I deploy a scalable, reliable haproxy cluster on Amazon EC2?

We need some more advanced functionality than ELB provides (mostly L7 inspection), but it's not obvious how to handle things like heartbeat and high availability with something like haproxy using EC2. ...
20
votes
1answer
46k views

How to set up stats for HAProxy?

I can't figure out how to set up stats for HAProxy. This is my configuration: global log 127.0.0.1 local0 log 127.0.0.1 local1 notice daemon #debug user haproxy group haproxy ...
18
votes
2answers
2k views

Outlook fails to connect to a load-balanced Exchange 2013 cluster through Direct Access 2012 R2

We have a load-balanced Exchange 2013 SP1 cluster, running MAPI over HTTP. Client connectivity inside our own network works just fine, while clients connected over Direct Access does not connect. The ...
16
votes
3answers
15k views

When using TCP load balancing with HAProxy, does all outbound traffic flow through the LB?

I am setting up an app to be hosted using VMs(probably amazon, but that is not set in stone) which will require both HTTP load balancing and load balancing a large number(50k or so if possible) of ...
15
votes
7answers
36k views

How can I use HAproxy with SSL and get X-Forwarded-For headers AND tell PHP that SSL is in use?

I have the following setup: (internet) ---> [ pfSense Box ] /-> [ Apache / PHP server ] [running HAproxy] --+--> [ Apache / PHP server ] ...
15
votes
2answers
2k views

How is a single IP address load balanced?

I'm aware of "round robin DNS" load balancing, but how can a single IP address be load balanced? Google's DNS servers for example, 8.8.8.8 and 8.8.4.4. Wikipedia's load balancing article states: ...
14
votes
2answers
9k views

Do HTTP reverse proxies typically enable HTTP Keep-Alive on the client side of the proxied connection and not on the server side?

HAProxy has the ability to enable HTTP keep-alive on the client side (client <-> HAProxy) but disable it on the server side (HAProxy <-> server). Some of our clients connect to our web service ...
14
votes
5answers
23k views

Hardware vs Software load balancers: Just a cost issue?

If cost were not an issue, would there be any benefit in deploying a software load balancer for web traffic compared to a hardware one?
14
votes
2answers
582 views

Campus Network Design - Firewalls

I am designing a campus network, and the design looks like this: LINX is The London Internet Exchange and JANET is Joint Academic Network. My goal is an almost-fully redundant with high ...
14
votes
3answers
13k views

GlusterFS vs Ceph, which is better for production use for the moment? [closed]

I am evaluating GlusterFS and Ceph, seems Gluster is FUSE based which means it may be not as fast as Ceph. But looks like Gluster got a very friendly control panel and is ease to use. Ceph was ...
13
votes
5answers
14k views

Windows replacement for HAProxy

It does not appear that there is a similar question to this already posted, so I will go ahead and ask. I am working on a project that could benefit from having two - four servers handling incoming ...
12
votes
5answers
19k views

How do I Install Intermediate Certificates (in AWS)?

I have installed private key (pem encoded) and public key certificate (pem encoded) on Amazon Load Balancer. However, when I check the SSL with site test tool, I get the following error: Error ...
12
votes
3answers
7k views

Issues with EC2 Elastic Load Balancer DNS and routing

We're trying to run a fairly straightforward setup on Amazon EC2 - several HTTP servers sitting behind an Amazon Elastic Load Balancer (ELB). Our domain is managed in Route53, and we have a CNAME ...
12
votes
2answers
11k views

LVS vs HAProxy, which should I choose?

I am looking for a solution to load balancing and failover strategy, mainly for big web applications. We have many services to be balanced, such as web, MySQL, and many other HTTP or TCP based ...
11
votes
2answers
14k views

How to divert traffic based on hostname using HAProxy?

I've had some initial success with HAProxy setting up a bunch of app servers listening on various other ports. I now have another webserver listening on one port, and i'd like to what changes to make ...
11
votes
8answers
3k views

Load balancing Apache on a budget?

I am trying to get my head around the concept of load balancing to ensure availability and redundancy to keep users happy when things go wrong, rather than load balancing for the sake of offering ...
11
votes
3answers
11k views

How do you create a zone apex alias that points to a Elastic Load Balancer in the Route 53 GUI?

I created aliases for my domain name's zone apex using the ELB CLI as described in Elastic Load Balancing Developer Guide. I also added a AAAA record using the --rr-type AAAA flag, which is not ...
11
votes
2answers
20k views

nginx automatic failover load balancing

I'm using nginx and NginxHttpUpstreamModule for loadbalancing. My config is very simple: upstream lb { server 127.0.0.1:8081; server 127.0.0.1:8082; } server { listen 89; ...
11
votes
7answers
3k views

How can I balance incoming web traffic amongst N apache servers?

I am looking to use something like Heartbeat/Squid/Varnish/etc to balance the amount of incoming traffic amongst the internal apache instances. This would have to be software and not hardware as all ...
11
votes
7answers
8k views

Wordpress Installation on Two Servers - Loadbalancing

I have to install wordpress (One Blog, one domain, for e.g. mycompany.com/blog) on two servers sharing one database on a different server, these two servers are behind a loadbalancer and the db would ...
11
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5answers
14k views

How to load-balance SQL Server 2008 for high-usage ASP.NET applications?

Imagine that you have a successful web application that uses ASP.NET and IIS 7. It generates many calls to a SQL Server 2008 database, and is expected to be available to the public with 99.9% uptime ...
10
votes
4answers
8k views

What are the Differences between HAProxy and Ngnix in reverse proxy mode?

What are the differences between HAProxy and Nginx when it comes to their abilities as a reverse proxy?
10
votes
6answers
4k views

What is a typical method to scale out a software load balancer?

I often see web app architectures with a SLB / reverse-proxy in front of a bunch of app servers. What happens when the number of connections to the SLB requires too many resources for a single SLB to ...
10
votes
3answers
29k views

What is the downside to sticky sessions with load balancers?

We have a web farm of IIS7 machines which work great. In front of them is an F5 Big-IP hardware load balancer, also working fine :) Currently we're using an ASP.NET State Service to handle our ...
10
votes
4answers
8k views

Load Balancing a UDP server

I have a udp server, it is a central part in my business process. in order to handle the loads I'm expecting in the production environment I'll probably need 2 or 3 instances of the server. The server ...
10
votes
2answers
3k views

Is there a way to add more backend server to haproxy without restarting haproxy?

We want to be able to add more backend servers on demand. Right now I don't see a way to add more backend servers to the config file without restarting haproxy.
10
votes
6answers
7k views

Best way to load balance across multiple static file servers for even an bandwidth distribution?

First off, I'll explain my situation to you. I'm running a fairly popular website as a side project, so I can't really invest a ton of money into it. I currently have just one server with HAProxy in ...
10
votes
4answers
3k views

Load balancing using IIS7 request routing and load balancing module

Microsoft has a lot of documentation about their somewhat new load balancing and request routing module for IIS7 located here: ...
10
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5answers
6k views

Solution to route/proxy SNMP Traps (or Netflow, generic UDP, etc) for network monitoring?

I'm implementing a network monitoring solution for a very large network (approximately 5000 network devices). We'd like to have all devices on our network send SNMP traps to a single box (technically ...
10
votes
1answer
690 views

iproute multiple ADSL load balancer through VM

For a long time (2 years?) I have been running a virtual machine (Ubuntu 12.04 server) with a very basic outbound load balancing capability, sending different outbound connections out different ADSL ...
9
votes
8answers
68k views

Point Multiple IP Addresses to a Single Host Name

In Windows System, there is this file at C:\WINDOWS\system32\drivers\etc\hosts. This file allows us to default a specific IP address to a host name. The issue now is whether I can set multiple IP ...
9
votes
2answers
19k views

Load balancing & NAT-ing multiple ISP connections on Linux

I have two internet connections from two different ISPs and I need to balance the traffic originating to and from my network between the two ISPs. I am using Debian GNU/Linux. My set-up is like this ...
9
votes
3answers
573 views

How to make redundant load balancers?

I understand that the purpose of load balancers is to balance load between your servers and keep track of instance health, etc. But what if load balancer itself fails? How do you set up redundant load ...
9
votes
5answers
1k views

What are the best techniques for preventing denial of service attacks?

Currently I have been using (D)DoS-Deflate to manage such situations on numerous remote servers, along with Apache JMeter for load testing. Overall it has been working fairly well, although I'd like ...
9
votes
4answers
2k views

Advantages of Using Nginx or HA Proxy as Load Balancer

In our environment we us both Nginx and HA Proxy on different clusters. Are there advantages of using one over the other? Or, what is the best way to go about load balancing a basic LAMP server ...
9
votes
5answers
1k views

Spanning Tree Setup

I understand the basics of spanning tree, but that's about it. I'm hoping that someone can tell me if this will work as I want it to. I've got two Cisco ACE load balancers setup for redundancy. ...
8
votes
3answers
13k views

How to setup HAProxy with failover?

I understand that, to get failover on an HAProxy load balancing setup, you need two machines running HAproxy (and route it to several webserver instances). But in this case, say abcd.com, how do we ...
8
votes
5answers
3k views

What is the practical limit for IP addresses in DNS round-robin?

I'm currently running a site whose trafic is distributed among 7 mirror servers right now (using DNS round robin). But soon more mirrors will be necessary given the high amount of traffic which is ...
8
votes
3answers
3k views

How to allow elastic load balancer through port 80 in security groups?

I want to temporarily block port 80 for the outside world, but want the load balancer to pass through the firewall (via security group) so it won't see the instance as unhealthy. How can I do that? ...
8
votes
2answers
5k views

Load Balancing Best Practices for Persistence

We run a web application serving up web APIs for an increasing number of clients. To start, the clients were generally home, office, or other wireless networks submitting chunked http uploads to our ...
8
votes
3answers
4k views

What kind of load balancing algorithms are there

I was researching different load balancing algorithms for HTTP and I just found 3. Random, Round Robin and Weighted Round Robin. Are there any other options? Thanks Paul
8
votes
4answers
2k views

How to limit number of sessions?

I need a way to track and limit web sessions to a web app. A "session" is loosely defined as the single user browsing the pages of the said web app. I think it can be translated to: a session is ...
8
votes
2answers
3k views

EC2 Update my existing AMI

I'm using Elastic Load Balancing to load balance my Auto Scaling Group, for that I have a private AMI that hold my application server (Tomcat) and my web app deployed to it as war ... Now everything ...
8
votes
4answers
808 views

External load balancer solutions between EC2 and Rackspace

I have a website primarily hosted on EC2 with the backends (MySql) replicated async to a Rackspace store. I am also planning to have a suite of web server, cache & db on standby at Rackspace in ...
7
votes
6answers
7k views

Linux equivalent of Windows NLB

With Windows, we can setup load balancing for arbitrary IP services just by installing NLB and selecting which nodes we want in the cluster. It does some MAC address changing, then has algorithms to ...