cluster-computing

问题 I don't have a clustered environment at present, but I was curious about @ApplicationScoped behaviour in a clustered environment. Is there going to be only one across the cluster or is still still one per JVM in the cluster? I have read that @Singleton gets created per JVM in How singleton is javax.ejb.Singleton in a clustered environment? 回答1: References to @ApplicationScoped are proxied, so they will be correctly resolved by the CDI container. That holds true no matter how many nodes are

问题 The setup I have a Wildfly 8.2.0.Final application server running a cluster in domain mode using the full-ha profile. The cluster consists of two instances of wildfly, master and slave, each running on its own virtual machine. The application My project is deployed as a war-file on the application server. For test purposes my loadbalancer distributes the requests using round-robin. Anonymous users can use the service provided by this project using a button, which will call in two steps first

问题 I have created a cluster consists of three RabbitMQ nodes using join_cluster command. i.e. rabbitmqctl –n rabbit2@MYPC1 join_cluster rabbit2@MYPC1 (currently the cluster runs on a single computer) Questions: In the documents it says there is one implemetation for active passive and one for active active. What did I configure? How do I know? How can it be changed? Is there a big performance trade off between Active Active & Active Passive? What is the best practice to interact with active

问题 Super EDIT: Adding the broadcast step, will result in ncols to get printed by the two processes by the master node (from which I can check the output). But why? I mean, all variables that are broadcast have already a value in the line of their declaration!!! (off-topic image). I have some code based on this example. I checked that cluster configuration is OK, with this simple program, which also printed the IP of the machine that it would run onto: int main (int argc, char *argv[]) { int rank

问题 I'm trying to force nodes into different clusters in force layout based on a certain attribute in the data like "group." I'm adapting the code from Mike Bostock's multi foci force layout example (code, example) and I've been successful in adding in my own data but I haven't been able to specify how many clusters there are and how to assign a node to a cluster. I'm relatively new to d3 and JavaScript and I haven't been able to find many examples of multi foci applications. Here's my d3 code,

问题 I have been using sharding with multiple basic solr server for clustering. I also used one embedded solr server (Solrj Java API) with many basic solr servers and connecting them by sharding as embedded solr server is the caller of them. I used the code line below for this purpose. SolrQuery query = new SolrQuery(); query.set("shards", "solr1URL,solr2URL,..."); Now, I have many embedded solr servers running on different computers and they are unaware of each others. I want to communicate them

问题 I just figured out how to send jobs to be processed on machines on the cluster by using Condor. Since we have a lot of machines and not each of those machines are configured the same, I was wondering: Is it possible to tell condor only to dispatch my jobs (python scripts) to machines, that have numpy installed on them since my script depends on this package? 回答1: Like any other machine attribute, you just need to advertise it in the machine classad, and then have your jobs require it. To

问题 I am in the final stages of configuring a service that is accessible from four global locations (with plans to add more later). I will be running the servers on an Ubuntu 12.04 box with MariaDB. My initial thought was to create servers that run independently of each other with 4 distinct databases and live with the constraint that users would only be able to login to the server where they were initially registered. However, I have just run into this article that has got me thinking... . From

问题 What are the best methods/algorithms available to select a leading node in a cluster of nodes, knowing that nodes come up and down at anytime? If implementations are available in Java, it is a plus. 回答1: I've implemented the Paxos algorith before in Java. It's very useful, and fairly simple. (It took about 16 hours to put together a demo of it, using Threads to simulate servers. I was also much worse at threading then!) It won't help you select the leader exactly... but what it will do is

问题 The lock statement ensures that one thread does not enter a critical section of code while another thread is in the critical section. However, it won't work if the workload is spread across a farm of servers (e.g. a few IIS servers + a load balancer). Does .NET support such a scenario? Is there any class that can be used to control the execution of a critical code section by threads running on multiple machines? If not, is there any standard method of handling such problems? This question was