I have an application that's a mix of Java and C++ on Solaris. The Java aspects of the code run the web UI and establish state on the devices that we're talking to, and the C++ code does the real-time crunching of data coming back from the devices. Shared memory is used to pass device state and context information from the Java code thro...
When you roll out changes to a live web site, how do you go about checking that the live system is working correctly? Which tools do you use? Who does it? Do you block access to the site for the testing period? What amount of downtime is acceptable? ...
I would like to make 2 TB or so available via NFS and CIFS. I am looking for a 2 (or more) server solution for high availability and the ability to load balance across the servers if possible. Any suggestions for clustering or high availability solutions? This is business use, planning on growing to 5-10 TB over next few years. Our faci...
What's the difference between failover and disaster recovery? ...
The application is planned to be built using ASP.NET, .NET Remoting & MS SQL Server. High availability is required at presentation layer, application layer and database. Does IIS 7.0 provide any advantages over IIS 6.0 in regard to the High availability aspect? ...
One of my goals is to be able to deploy a new version of a web application that runs side by side the old version. The catch is that everything shares a database. A database that in the new version tends to include significant refactoring to database tables. I would like to be rollout the new version of the application to users over ti...
I've heard a lot of people touting success using Linux based proxies to handle routing for high availability of web applications, but what are others doing with web services? I have a bank of WCF services that need to be moved to a high availability (failover) model, meaning that if a particular server hosting the WCF services goes down,...
We have two web servers with load balancing. We need to share some files between those servers. These would be uploaded files, session files, various files that php applications create. We don't want to use a heavyweight, no longer maintained or a commercial solution. We're looking for some lightweight open-source software that would wo...
Is there a PostgreSQL HA solution that can handle a splitbrain situation gracefully. To elaborate, the system i'm working on is expected to run in several areas with users close to the servers there and connectivity between the zones is known to be questionable. I'd like for the users to be able to continue using the system in a degrad...
I've been working on a project, which is a combination of an application server and an object database, and is currently running on a single machine only. Some time ago I read a paper which describes a distributed relational database, and got some ideas on how to apply the ideas in that paper to my project, so that I could make a high-av...
Looking for opinions on the modularization of web applications. Already most applications regardless of language have a backend DB and support tie-ins with their respective web application server (Apache, IIS, Lighttp, etc ) but a lot of developers I've dealt with have problems coming to terms with using Memcached or anything outside of...
We are currently running a Java integration application on a Linux box. First an overview of the application. The Java application is a standalone application (not deployed on any JEE application server like OracleAS,WebLogic,JBOSS etc). By Stand Alone I mean its NOT a DESKTOP application. However it is run from the command line from a ...
What changes to a database (MySQL in this case) does Hibernate survive (data, schema, ...)? I ask this because of zero downtime with Hibernate. Change database, split app servers into two clusters, redeploy the application on one of the clusters and switch application. Thanks Stephan ...
I am a total newbie to the world of SOA. As such, I am looking at some "SOA frameworks/technologies", and trying to understand how to utilize them to build a highly scalable (Facebook class) website. There are several "pains" I am trying to solve here: Composability (+ managing dependencies, Pub/Sub) Language-independence of services ...
I work for a software shop, which has an in house predictive dialer product, and we need to implement a solution to obey to the DO-NOT-CALL lists. Basically, I have a database with the customers/prospective customers that I need to call, and another database with the phone numbers I can't call. As the system is a predictive dialer, bas...
If you had to audit a Java application for worst-practices when it comes to high-availability and disaster recovery, you would probably look for hardcoded IP addresses and suboptimal caching of bind handles. What else should be considered? ...
Likewise are there design patterns that should be avoided? ...
So lets say I have an N sized server array set up like so: I have a simple JavaBean/POJO: package example; public class Person { private OtherObject obj; public void setObj(OtherObject theObj) { synchronized (this) { obj = theObj; } } public OtherObject getObj() { synchronized (this) { return obj; ...
Some background: on Linux HA, resources and groups have scores, i.e. score=(preference + stickness - failure stickness*fail counter). When a backup node has score greater than that of the current node, the resource will move to the backup node. I need to check, for a given resource/node, if that score is negative. It is easy to get fai...
Hello, I'm facing a bit of difficulties implementing the HA for my ActiveMQ service. Right now, I've correctly implemented the Master / Slave brokers of Active MQ, so if the master dies, the slave takes over the message delivery transparently. They both share a Microsoft SQL database to store the messages. I wanted to add another level...