clustering

Weblogic Managed Servers Restart On Own

We are running WebLogic 8.1.6.0 and when we attempt to shutdown all managed servers in a cluster some of the managed servers shutdown and start back up prior to us interacting with them. In order to stop all of the managed servers we have to manual force shutdown each server that “restarts” it’s self and often the manually process must b...

what is the concept for clustering web apps ?

Hi, I am going to built a web apps that (hopefully) someday it could serve thousand or may be millions users. Now, I need to know concept of clustering web apps. I have no experience about this in the past. For example, I have 2 servers, one located in Australia and the other located in USA. Both will be a cluster so they share the s...

Production system running JBoss clustering

Hi, What are some of the largest systems that use JBoss clustering? What are the specs/config? I want to know whether JBoss cluster is really scalable or not. Thanks ...

Can J2SE applications be clustered

Hi there all, i have numerous Corba servers and some other java apps (not web). I wish to cluster them if possible. Can this be done ? ...

Reordering matrix elements to reflect column and row clustering in naiive python

Hello, I'm looking for a way to perform clustering separately on matrix rows and than on its columns, reorder the data in the matrix to reflect the clustering and putting it all together. The clustering problem is easily solvable, so is the dendrogram creation (for example in this blog or in "Programming collective intelligence"). Howev...

Scaling Java applications - existing cluster-aware IoC frameworks?

Most people use some kind of an IoC framework - Guice, Spring, you name it. Many of us need to scale their applications too, so they complicate their lifes with Terracotta, Glassfish/JBoss/insertyourfavouritehere clusters. But is it really the way to go? Are you using any of the above? Here's some ideas we currently have implemented in...

Python KMeans clustering words

Dear Everyone I am interested to perform kmeans clustering on a list of words with the distance measure being Leveshtein. 1) I know there are a lot of frameworks out there, including scipy and orange that has a kmeans implementation. However they all require some sort of vector as the data which doesn't really fit me. 2) I need a good...

Has anyone installed NServiceBus onto a Microsoft clustered server?

Update: Ok, after getting past the fact that I did not have MSDTC set up as a cluster resource (doh!), I was able to run my program and all appeared well, but I was not able to successfully send messages to it. After digging I found that while the private queues were created on one node of the cluster, they were not on the other node (I...

python parallel computing: split keyspace to give each node a range to work on

My question is rather complicated for me to explain, as i'm not really good at maths, but i'll try to be as clear as possible. I'm trying to code a cluster in python, which will generate words given a charset (i.e. with lowercase: aaaa, aaab, aaac, ..., zzzz) and make various operations on them. I'm searching how to calculate, given th...

Database backed clustered Quartz jobs - Are dynamicly created triggers automatically clustered?

Our use of Quartz so far has been to configure the database backed scheduler and any jobs/triggers in the spring config which is then loaded when the app is run on the cluster. Each server in the cluster then shares the triggers so that the triggers are only run by one of the servers each time. I now want to dynamically create new trigg...

OpenCV's cvKMeans2 - chosing clusters

Hi, I'm using cvKMeans2 for clustering, but I'm not sure, how it works in general - the part of choosing clusters. I thought that it set the first positions of clusters from given samples. So it means that in the end of clustering process would every cluster has at least one sample -> in the output array of cluster labels will be full ra...

Scipy.cluster.hierarchy.fclusterdata + distance measure

1) I am using scipy's hcluster module. so the variable that I have control over is the threshold variable. How do I know my performance per threshold? i.e. In Kmeans, this performance will be the sum of all the points to their centroids. Of course, this has to be adjusted since more clusters = less distance generally. Is there an obse...

Best practices for building a simple, scalable cluster on Amazon EC2 for a Java web app

I want to build a Java web app and deploy it on EC2. It will be written in Java and will use MySQL. I was hoping to get some pointers on the actual deployment process and configuration. In particular I'm interested in the following topics: machine images (DIY vs ready made) mysql replication and backup to S3 ways of deploying and redep...

EJB Reference Configuration Error

Hi, I have 2 ears say Ear1 and Ear2 for my application,which are deployed in clusters.Ear2 is having Ejb which is being called from Ear1. EJB reference is required for communication between Ear2 and Ear1.i am setting the below value to Target Resource JNDI Name: corbaloc::ClusterServer1:2810,:ClusterServer2:2810/cell/clusters/Cluster...

Clustering and DB Replication in virtualized (and cloud) environments

Both replication and clustering are terms for servers setups with physical (real) servers, usually implemented on a DB or AS level. Now the question: In a virtualized environment with "easy" scalable servers (touching clustering) and a higher availability (DB replication) through the means of high availability of the virtual server by t...

Using Appfabric cache with just one node and HA on

I am looking to use MS-Velocity a.k.a Appfabric Cache in a project that is starting by next month (so I am also assuming Q3 will have a go-live license). The project is a web application which will have at least 40K users in 6 months down. And we know for sure that cache server can be of only one node to start with and we will scale hori...

How to JBoss/Blazeds clustering and channel failover

Hi, I'm stuck with jboss and blazeds clusterization. What I have now is : 2 Jboss Instances, running in all mode One load balancer with apache and mod_jk, as suggested by Jboss docs A spring/flex integration app A flex application that I do not want to throw errors when one of my JBoss instances falls I find Adobe documentation reall...

Using the C Cluster library in Visual C++.

Right so i'm trying to use a C library in C++, never actually done this before i thought it would be a case of declaring the header includes under a extern "C" and setting the compile as flag to "default" but i'm still getting linker errors and think that the header file might have to be complied as a DLL. I have no idea really. Is it ...

Algorithms for finding closest vector

I have a set of vectors. For a vector in that set I like to find the sub set that is closeest to this vector. What algorithm can do this. ...

Cosine Similarity Measure: Multiple results

My program uses clustering to produce subsets of similar items and then uses the cosine similarity measure as a method of determining how similar the clusters are. For instance if user 1 has 3 clusters and user 2 has 3 clusters then every cluster is compared against each other, 9 results using the cosine similarity measure will be produc...