In a installation of WebSphere Application Server with Network Deployment, a node is: a physical machine an instance of operative system a logical set of WAS instances that is independent of physical machine or OS instance ...
I've been searching (with little success) for a free/opensource session clustering and replication solution for asp.net. I've run across the usual suspects (indexus sharedcache, memcached), however, each has some limitations. Indexus - Very immature, stubbed session interface implementation. Its otherwise a great caching solution, th...
We have a situation where users are allowed to upload content, and then separately make some changes, then submit a form based on those changes. This works fine in a single-server, non-failover environment, however we would like some sort of solution for sharing the files between servers that supports failover. Has anyone run into this...
Currently I am setting up an application that can deploy other web apps to Tomcat 6 clusters. It is set up right now to have a one to one relationship between deployed web application and a cluster. My current reasoning for this is so that I can change the JVM args of the Tomcat server without disrupting other applications and so that ...
I am looking for good example code for terracotta. Especially around using master/worker pattern. In particular using custom routing (we like, but would like to use some strick data affinity type routing - ie. one worker looks after a set of task types ). Also examples or experience setting up masters and topologies would be great als...
Would like to hear from people about their experience with java clustering (ie. implementing HA solutions). aka . terracotta, jgroups etc. It doesn't have to be web apps. Experience writing custom stand alone servers would be great also. UPDATE - I will be a bit more specific -> not that interested in Web App clustering (unless it ca...
I do a lot of work in the grid and HPC space and one of the biggest challenges we have with a system distributed across hundreds (or in some case thousands) of servers is analysing the log files. Currently log files are written locally to the disk on each blade but we could also consider publishing logging information using for exampl...
In one of the answers to Broadcast like UDP with the Reliability of TCP, a user mentions the Spread messaging API. I've also run across one called ØMQ. I also have some familiarity with MPI. So, my main question is: why would I choose one over the other? More specifically, why would I choose to use Spread or ØMQ when there are matu...
How does one automatically find categories for text based on content? ...
I need to write a couple of python scripts to automate the installation of Microsoft Cluster Ressources. More specifically, I'll need to query MS Cluster to be able to get a list of ressources with their parameters. And I also need to be able to create resources and set their parameters. Is someone knows if there is a package/module....
We have a 4 server cluster running ASP.NET web application using ASP.NET State Server Service for session. On one of the 4 servers ASP.NET State Server Service is running and other servers are configured to look at this. Very often we have to patch the servers, and applying patch on the State Server requires few minutes of downtime. Is...
At my house I have about 10 computers all different processors and speeds (all x86 compatible). I would like to cluster these. I have looked at openMosix but since they stopped development on it I am deciding against using it. I would prefer to use the latest or next to latest version of a mainstream distribution of Linux (Suse 11, Suse ...
Are there any algorithms that can help with hierarchical clustering? Google's map-reduce has only an example of k-clustering. In case of hierarchical clustering, I'm not sure how it's possible to divide the work between nodes. Other resource that I found is: http://issues.apache.org/jira/browse/MAHOUT-19 But it's not apparent, which algo...
I've been working on this for a few days now, and I've found several solutions but none of them incredibly simple or lightweight. The problem is basically this: We have a cluster of 10 machines, each of which is running the same software on a multithreaded ESB platform. I can deal with concurrency issues between threads on the same mac...
I have an application in which users interact with each-other. I want to visualize these interactions so that I can determine whether clusters of users exist (within which interactions are more frequent). I've assigned a 2D point to each user (where each coordinate is between 0 and 1). My idea is that two users' points move closer tog...
"Dirty reads", meaning reading an object's value even though it is write-locked by another thread, are described on Terracotta's website, yet I've heard that they shouldn't be used, even if you don't care about the possibility that you might get old data when you dirty-read the locked object. Does anyone have any experience of using dir...
I'm looking for techniques to generate 'neighbours' (people with similar taste) for users on a site I am working on; something similar to the way last.fm works. Currently, I have a compatibilty function for users which could come into play. It ranks users on having 1) rated similar items 2) rated the item similarly. The function weighs ...
Is there a way to deactivate the optimization for collocated objects that Weblogic uses by default for a specific EJB ? EDIT: Some context : We have a scheduler service that runs inside one node of the cluster. This is for historic reasons and cannot be changed at the moment. This service makes call to an EJB and we would like to load...
I'm working on a loosely coupled cluster for some data processing. The network code and processing code is in place, but we are evaluating different methodologies in our approach. Right now, as we should be, we are I/O bound on performance issues, and we're trying to decrease that bottleneck. Obviously, faster switches like Infiniband wo...
In an Oracle cluster (more than one machine co-operating to serve one database) will the "sysdate" function always return a consistent answer? Even if the servers' Operating System clock reports inconsistent values? ...