FAQ Database Discussion Community

Load balancing with nginx using hash method

I want to use nginx as a load balancer in front of several node.js application nodes. round-robin and ip_hash methods are unbelievably easy to implement but in my use case, they're not the best fit. I need nginx to serve clients to backend nodes in respect to their session id's...

How to scale horizontally Amazon RDS instance?

How to scale horizontally amazon RDS instance? EC2 and load balancer+autoscaling is extremly easy to implement, but if I want scaling amazon RDS? I can ugrade my RDS instance with more powerfull instance or I can create a read replica and I can direct SELECT queries to it. But in...

Weblogic load balancing and request re-routing to another server

I'm totally new to clustering and load balancing. What I'm trying to do is "Deploy Application on a Cluster which contains 2 managed servers. Now, If one of the managed server goes down, request should be redirected to another server which is Up." For Example: I've 2 managed servers (M1:7021...

Database query load balancing

I have several instances of an application running the same query against several SQL Server databases. There is a manual load balancing mechanism in place: each instance uses an algorithm to asimmetrically decide which server to query at a given time. The processing time of the query, and thus the...

How does CoreOS load balancing work out there in the wild on a cloud service?

Say I have a CoreOS cluster deployed on some cloud service somewhere. Now I have, say, 4 machines running a node.js app which follows all the 12-factor tenets and one machine with Couchbase. How does load balancing work in this scenario? Wouldn't ONE ip eventually run out of juice as...

Is it possible to load balance several services using the same HTTP load balancer in GCE?

I have one website and one api server on different instances: Is it possible to serve both of them through the same HTTP load balancer? Is there a down side to doing this vs. 2 load balancers? I went over these: https://cloud.google.com/compute/docs/load-balancing/http/ https://cloud.google.com/compute/docs/load-balancing/http/cross-region-example ...

Is it possible to use mysql proxy for query processing in front of microsoft sql server?

I want to use mysql proxy for processing queries trying to execute. I want to make this process available for all databases like mysql, ms sql server, oracle and ... is it possible to use mysql proxy as base engine and connect these database from that? if no, is it...

load balancing elasticsearch nodes for document / index writes and updates?

I am architecting a medium sized elasticsearch cluster (~20 nodes) with the three distinct node types Elasticsearch allows (master, data, and client) I am working on setting up load balancers to receive new documents and document updates for the Elasticsearch cluster. I have found Elasticsearch documentation on routing a document...

Invalid postback or callback argument when using loadbalancer and webgate

Hi I have developed an asp.net website which is deployed on two server. This site is working fine when I access the site using IP address of servers in URL like When I access site using loadbalancer DNS name (https://DNSName/Pagename.aspx) and webgate some of the pages are throwing following...

Is there any way to divide server resources between users of Java application?

I wonder if there is any possibility to split the users of Java application running under Tomcat by server resources? Problem description We have an application written in Java and running under the control of Tomcat server. Sometimes users could possibly do some actions leading to 100% charge of server...

AWS EC2 Load Balancing: point to specific AMI

I'm using the EC2 load balancer. Since I'm implementing my own autoscaling policy, I will not use to auto scaling EC2 service that I imagine is well integrated with the Load Balancer. Basically I will scale out istances all from the same AMI. I notice that the load balancer ask...

Azure load-balanced set preserves client IP

From experimenting with Azure load-balancing set, it seems that x-forwarded-for header is not used (as it would be expected in regular load-balancer), rather they preserve the original client IP. E.g.: app.get('/my-ip', function(req, res) { winston.log('/my-ip', 'x-forwarded', req.headers['x-forwarded-for'] || 'none', 'remoteAddress', req.connection.remoteAddress || 'none'); res.end(); }); With the result: /my-ip x-forwarded...

Unable to manually configure apache httpd 2.4.12 on ubuntu 13.10

I need to manually install apache httpd 2.4.12 on ubuntu 13.10. For some reasons I cannot use apt-get install. Having gone through the instructions provided for httpd installation, I execute the following commands in order Unzip the installation that was downloaded Navigate to the folder where the installation is present...

Network Load Balance

I'm having an issue while accessing an NLB cluster from node that is part of the cluster. Here is the scenario. I have created a NLB clusters on IP\ [Protocol: both with filtering Single Host] in unicast mode having three nodes\ -> Priority 2\ -> Priority 1...

Global Variables not updated due to load balancing

There are two servers running a web service and the servers are load balanced using HAProxy. Web Service does a post and updates a global variable with a certain value and another application running on the same servers will read this global value and does some processing. My issues is...

“Channel shutdown: connection error”

I've set up on AWS a RabbitMQ cluster with two nodes, and enabled HA as described here. Then, I set up an Elastic Load Balancer mapping 5672 to the instances' 5672 port, with a periodic health check to the instances' 15672 port (the HTTP management port). Then, I started two...

Reason why load balancers usually implemented in high-availability pairs?

Currently , I am doing some research about the load balancer . On Wikipedia , refer to this link http://en.wikipedia.org/wiki/Load_balancing_(computing). It says : "Usually load balancers are implemented in high-availability pairs which may also replicate session persistence data if required by the specific application." Besides , I have also used...

Bluemix Load Balancer Algorithm

What algorithm is used to balance HTTP load among several instances running on Bluemix? It seems I can use auto-scaling service to scale horizontally, and want to know what algorithm is used when balancing the load.

Azure linux load balance with neo4j

I have 3 machines running Linux. I set the load balance, but only the first set of machine availability responds to requests. When we turn off the first machine, the other two do not respond to external requests. I do not have configured iptables on Linux and no restrictive. Does...

which logic sould be followed using custom partitioner in map reduce to solve this

If in a file key distribution is like 99% of the words start with 'A' and 1% start with 'B' to 'Z' and you have to count the number of words starting with each letter, how would you distribute your keys efficiently?

How can I set up a load balancer for multiple virtual hosts (apache)

I am trying to set up a load balancer for a couple of virtual hosts on my apache server. These virtual hosts are added by adding the following lines for the file "C:\Windows\System32\drivers\etc\hosts": localhost vhosta vhostb vhostc load-balancer ::1 localhost Then I've added the following...

Google HTTP load balancing enforce HTTPS

I have a HTTP and HTTPS load balancer on Goole Cloud. Is it possible to set it up to enforce (redirect) all connections to HTTPS?

How do I configure SSL with Laravel 5 behind a load balancer (ssl_termination)?

I have a laravel 5 project deployed to AWS EC2 web instances, behind an ELB with ssl termination. For things like assets, Laravel by default uses whatever scheme is currently used. However, I've noticed since the https traffic is decrypted by the ELB and forwarded to the EC2 nodes via...

Relationship between HTTPS Healthchecks and an HTTPS connection to a GCE Instance

I'm setting up HTTPS Load Balancing (LB) on Google Compute Engine (GCE). Key components are outlined in the Overview Diagram. After successfully creating a HTTP Backend Service where 1 of 1 (GCE) instance is healthy, I decided to do the same for HTTPS. I'm using the Developer Console UI to...

How to access the nodes behind the amazon load balancer directly

I have an application running on elastic beanstalk. The application is load balanced, and the SSL is handled by the load balancer. How do I securely access the individual nodes in the cluster? I want to do this so that I can connect via JMX and interrogate the individual nodes...

Can I run multiple private docker registry behind load balancer?

I was wondering if it's possible to run multiple docker registry hosts under an ELB or (any load balancer for that matter). I am planning to run the private docker registry inside a docker container. Has anyone tried that? Any ideas for how to have Docker registry containers autoheal without...

Barracuda 340 Load Balancer Won't Port Forward

We have Barracuda 340 that we are trying to set up for load balancing across multiple servers, each with multiple applications running. If I set up a service with the specific port we are sending UDP packets to, and one IP per Real Server (with the same port as the...

How to implement new load balancing algorithm in nginx?

can i implement new load balancing algorithm in Nginx for test? i wanna try to implement one method for load balancing using content-based algorithm but i don't know how to use this implementation in my cluster

How does Amazon Auto scaling work in a DDos attack

I have setup my auto scaling group to add a new EC2 instance when Elastic Beanstalk CPU usage above 60% for 5 mins. I get that but what happen if adding 1 instance is not enough and CPU usage is still above 60%, does auto scaling group add more EC2...

Load Balancer with Healt Check for JBoss 7.1 or Apache

I need to set up a high availability solution for 2 servers JBoss 7.1 or Apache, I read the documentation and I find mod_cluster and ajp but they don't have health check. Need to assemble a solution with 2 servers JBoss and 2 load balancers. Which solution for Load Balancer...

reverse domain name row key, automatic splitting, and load balancing

I'm designing an HBase schema with a row key that starts with the domain name reversed. E.g., com.example.www. Although there are many more domains that end in .com than say .org or .edu, I assume that I don't have to manage splitting myself, and I can rely on HBase's automatic...