Tagged Questions
54
votes
5answers
2k views
64-bit JVM limited to 300GB of memory?
I am attempting to run a Java application on a cluster computing environment (IBM LSF running CentOS release 6.2 Final) that can provide me with up to 1TB of RAM space.
I could create a JVM with up ...
35
votes
9answers
16k views
Singleton in Cluster environment
What is the best strategy to refactor a Singleton object to a cluster environment?
We use Singleton to cache some custom information from Database. Its mostly read-only but gets refreshed when some ...
24
votes
8answers
11k views
Cluster Shared Cache [closed]
I am searching for a java framework that would allow me to share a cache between multiple JVMs.
What I would need is something like Hazelcast but without the "distributed" part. I want to be able to ...
19
votes
4answers
5k views
RealWorld HazelCast
Does anyone have any real world experience with Hazelcast distributed data grid and execution product? How has it worked for you? It has an astonishingly simple API and functionality that seems ...
17
votes
3answers
2k views
How to notify all (same) Singleton beans in a Glassfish 3.1 Cluster?
I have a JEE6 application that runs on an Glassfish 3.1.2 cluster.
One @Singleton Bean contains some kind of (readolny) cache. A User can press a button in the GUI to update the cache with (updated) ...
16
votes
4answers
9k views
Share Sessions between tomcat instances (without using Sticky Sessions)
I'm going to have 3 Tomcat servers and a Load Balancer that dispatches the requests without using 'sticky sessions'.
I want to share sessions' data between the servers and I'm thinking in persisting ...
10
votes
3answers
2k views
Jetty/Tomcat encrypted cookie-based session storage?
Ruby on Rails has supported signed cookie-based sessions for quite some time, with a few encrypted implementations springing up since then. Python and PHP also have implementations.
Does such a beast ...
jetty
10
votes
3answers
2k views
Java 8 MapReduce for distributed computing
It made me happy when I heard about parallelStream() in Java 8, that processes on multiple cores and finally gives back the result within single JVM. No more lines of multithreading code. As far as I ...
9
votes
1answer
3k views
JGroups, Terracotta & Hazelcast
Trying to wrap my head around these 3 projects and they all seem to handle slightly different problems that arise when trying to cluster. But all the documentation for them is sort of written for ...
8
votes
3answers
2k views
Java EE Application-scoped variables in a clustered environment (Websphere)?
Is there any easy way in a Java EE application (running on Websphere) to share an object in an application-wide scope across the entire cluster? Something maybe similar to Servlet Context parameters, ...
7
votes
8answers
3k views
How to create a Linux cluster for running physics simulations in java?
I am developing a scientific application used to perform physical simulations. The algorithms used are O(n3), so for a large set of data it takes a very long time to process. The application runs a ...
7
votes
10answers
963 views
Architectural issue with Tomcat cluster environment
I am working on project in which we have an authentication mechanism. We are following the below steps in the authentication mechanism.
The user opens a browser and enter his/her email in a text box ...
7
votes
1answer
3k views
Tomcat's Clustering / Session Replication not replicating properly
I'm setting up clustering/replication on Tomcat 7 on my local machine, to evaluate it for use with my environment/codebase.
Setup
I have two identical tomcat servers in sibling directories running ...
6
votes
5answers
5k views
Running Tomcat in production environments [closed]
I am currently using Tomcat6 as a Web-Container on development and production.
I have heard that Tomcat is not the best performing Web-Container for production environments. Is this true?
Is Tomcat ...
6
votes
1answer
17k views
ORA-01654: unable to extend index
Calling all Oracle Gurus!
I am in the process of clustering a well tested application on WebSphere. The application in question made it about half way through processing 1k of JMS messages from a ...
6
votes
4answers
2k views
Singletons with TimerManager on WebSphere Cluster
How can I get a timer task on a WebSphere cluster to execute once and only once? I know this is possible on other app servers but can't figure out how to do this in WebSphere.
6
votes
5answers
3k views
experience with java clustering?
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 ...
6
votes
1answer
400 views
Interrupting a job in quartz cluster
I have a Quartz setup with multiple instances and I want to interrupt a job wherever it is executed. As it was said in documentation, Scheduler.interrupt() method is not cluster aware so I'm looking ...
6
votes
3answers
2k views
RabbitMQ on EC2 performance challenges
What could be performance expectations of RabbitMQ on EC2? Would appreciate sharing experience here.
I am trying to do some performance test of RabbitMQ on aws EC2. I have 3 separate EC2 instance ...
5
votes
5answers
6k views
Sharing a Java synchronized block across a cluster, or using a global lock?
I have some code that I want to only allow access to by one thread. I know how to accomplish this using either synchronized blocks or methods, but will this work in a clustered environment?
The ...
5
votes
2answers
5k views
Hibernate L2 cache. Read-write or transactional cache concurrency strategy on cluster?
I’m trying to figure out which cache concurrency strategy should I use for my application (for entity updates, in particular). The application is a web-service developed using Hibernate, is deployed ...
5
votes
1answer
1k views
Java Parallel Processing on cluster systems (cluster computing)
I am developing a web-based application to provide some services. This is a scientific application which performs some processing on data uploaded by users. The methods corresponds to this processing ...
5
votes
2answers
1k views
How would a job scheduler like quartz work when you have multiple servers?
When you have multiple servers all running the same web application, how would you make sure multiple jobs don't get fired off (the same job)?
Would you have to use the database to monitor if the job ...
5
votes
4answers
704 views
Discovery mechanics API for Java-based app
I currently participate in a project where we/the applicaition need to be able to discover other instances of the application with the same application name running on a LAN (henceforth called Node).
...
5
votes
3answers
4k views
In Hadoop where does the framework save the output of the Map task in a normal Map-Reduce Application?
I am trying to find out where does the output of a Map task is saved to disk before it can be used by a Reduce task.
Note: - version used is Hadoop 0.20.204 with the new API
For example, when ...
5
votes
2answers
5k views
How to cluster and load balance a Spring + OSGi app
I am considering to develop an web application with Spring and OSGi. It seems like they fit together nicely. What are the options for clustering and loadbalancing such an app and what are the pros and ...
5
votes
2answers
819 views
Schedule job executes twice on cluster
We are using Cron4j java scheduler for scheduling jobs which execute every night. Now, when this same web application is deployed(Tomcat) on cluster(2 nodes) at the client's site the jobs run twice. ...
5
votes
5answers
2k views
Best way to deploy a Java application on a cluster of servers?
I have a cluster of 32 servers and I need a tool to distribute a Java service, packaged as a Jar file, to each machine and remotely start the service. The cluster consists of Linux (Suse 10) servers ...
5
votes
1answer
1k views
How to programmatically find/list all nodes in a J2EE Application-Cluster?
Is there a way to find all nodes belonging to the cluster of the web-application? I know on JBoss i can use HAServiceMBeanSupport to get information about all nodes(hostname, IP-adress), but how can I ...
4
votes
4answers
9k views
Difference between Clustering and Load balancing? [closed]
What is the difference between Clustering and Load balancing?
I know it is a simple question.But I asked this question to several people, But no one gave reliable answer.
Also I googled a lot and ...
4
votes
3answers
1k views
How are static objects treated while clustering?
Static objects are initialized only once. Singleton classes are instantiated only once. If we use a singleton in a cluster then it will create multiple instances of singleton in the clusters.
So what ...
4
votes
3answers
1k views
Spring Framework Connecting JVM with each other
I have 4 servers and JVM is installed on them. I wrote a java service that Quartz calls this services every 10 minutes. But in 4 servers, every 10 minutes 4 calls are done. This sitiuation creates ...
4
votes
3answers
3k views
How often is a programmatic created EJB Timer executed in a cluster?
In a clustered JEE6 environment (Glassfish 3.1.2), a @Singleton bean is/can be created on every cluster node. If this Singleton Bean registers a programmatic timer on its @PostConstruct - how often ...
4
votes
3answers
832 views
Serializing in java: automatic thread-safety?
If you serialize an object in Java and send it (over a socket) to nodes in a cluster do you automatically get thread safety?
Say you have a cluster and each node has several cores. The server has a ...
4
votes
1answer
2k views
Hibernate Search in a Clustered Configuration?
I have a Java web app that I'm developing, using JBoss Seam as the application framework. I'd like to take advantage of Hibernate Search to provide entity searching capabilities. The integration has ...
4
votes
1answer
387 views
speed up java maven compile on amazon clustering
just a wild idea. wonder is it possible to compile maven build on amazon clustering machines to speed up build processes? any reference or guide on this?
reference
4
votes
3answers
493 views
Clustering JVM
I have a situation where I need to induce asynchronous behavior in a synchronous application.
To elaborate, there is a monolithic c++ application which synchronously produces pricing for complex ...
3
votes
2answers
482 views
Java and string.hashCode() stability across machines in cluster [duplicate]
I have asked similar question for the string.GetHashCode() method in .NET. Taken from then, I have learned that we cannot rely on the implicit implementation of hash code for the buit-in types, if we ...
3
votes
2answers
326 views
Questions on Java and Scala and parallelization
So, I have a couple of questions about scala.
1) Would writing a new project in scala be speedier (in terms of performance) or should I just stick to regular java? The project that I am going to ...
3
votes
4answers
4k views
Looking for terracotta examples
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 ...
3
votes
4answers
2k views
How to Handle Singleton Classes in Distributed Environment
When an Application is Distributed across multiple JVMS my single ton class will have multiple instances at each JVM. I have to generate a Unique ID for this purpose i have to use a singleton pattern ...
3
votes
3answers
925 views
Automatic selection of a leader in a cluster of nodes
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.
3
votes
2answers
2k views
Java high scalable application with Hazelcast
I'm developing high-scalable application, so I decided to use Hazelcast for it. I have one frontend server, which puts messages for nodes. Every node in cluster change it's workload in background ...
3
votes
2answers
1k views
How to run a Scheduled Method in a Cluster for one Node and for All?
I have a Glassfish 3.1.2 that runs in a cluster and a EJB 3.1 application. And I need two kind of Scheduled Methods in my application:
one kind that runs only once (on a single node) once a day
and ...
3
votes
3answers
1k views
JMS/AMQP brokers comparison
After reading some interesting posts here on SO, and many pages found on google, I would like to ask you for help with decision what JMS/AMQP broker to choose. We are facing simple problem in our ...
3
votes
1answer
587 views
Spark cluster fails on bigger input, works well for small
I'm playing with Spark. It is the default, pre-built distribution (0.7.0) from the website, with default config, cluster mode, one worker (my localhost). I read the docs on installing and everything ...
3
votes
2answers
2k views
JBOSS domain mode, run on specific IP
I'm trying to pass this tutorial about clustering in JBOSS http://blog.akquinet.de/2012/06/29/managing-cluster-nodes-in-domain-mode-of-jboss-as-7-eap-6/
and I got stuck on running JBOSS on specific IP ...
3
votes
4answers
3k views
clustering and loadbalancing through Java EE
I want to develop clustering and load balancing by using Java EE, I want to use two Tomcats in back-end,If any request arrives to my application it should send request to the tomcats based on the load ...
3
votes
2answers
1k views
Java Frameworks in the Cloud
So I'm trying to finally grasp how cloud-based, enterprise applications work, and what their architectures typically look like. Say I use a cloud provider like Amazon. I assume (please correct me if ...
0
votes
0answers
5 views
Sticky Session mode not working correctly for process taking long time
I have an implementation in which data needs to be exported to a file . Since size of data is very large therefore we display a progress bar that shows the progress status of records written so far . ...
