I have some jobs that run in my application (These jobs created and managed by the application) and the application is deployed on a cluster of 2 managed servers.
We have distributed the load based on the even and odd number of the jobs on these 2 managed servers.
Now, we want to create the jobs if one of the instances goes down into the other instance.
How do we know if the other instance went down in Weblogic server cluster and my application is built in Java and spring.
Thanks
Related
I have coded a Spring MVC Hibernate application with RabbitMQ as a messaging server & a MySQL DB. I have also used Hazelcast an in-memory distributed cache to centralize the state of the application, moving the local tomcat session to a centralized session & implementing distributed locks.
The app right now is hosted on a single tomcat server in my local system.
I want to test my application on a multiple JVM node environment i'e app running on multiple tomcat servers.
What would be the best approach to test the app.
Few things that come to my mind
A. Install & configure a load balancer & set up a tomcat cluster in my local system. This I believe is a tedious task & requires much effort.
B. Host the application on a PAAS like OpenShift, cloudfoundry but I am not sure if I will be able to test my application on several nodes.
C. Any other way to simulate a clustered environment on my local windows system?
I would suggest first you should understand your application requirement. For the real production/live environment, are you going to use Infrastructure as a service or PAAS.
If Infrastructure as a service then
I would suggest create local cluster environment and use the tomcat and spring application sticky session concept. Persist the session in Hazelcast or redis server installed on different node. Configure load balancer for multiple nodes having tomcat server. 2-3 VMs for testing purpose would be suitable.
If requirement is PAAS then
Don't think about local environment. Test directly on OpenShift or AWS free account and trust me you would be able to test on PAAS if all setup is fine.
I am using spring batch local partitioning to process my Job.In local partitioning multiple slaves will be created in same instance i.e in the same job. How Remote partitioning is different from local partitioning.What i am assuming is that in Remote partitioning each slave will be executed in different machine. Is my understanding correct. If my understanding is correct how to start the slaves in different machines without using cloudfoundry. I have seen Michael Minella talk on Remote partitioning https://www.youtube.com/watch?v=CYTj5YT7CZU tutorial. I am curious to know how remote partitioning works without using cloudfoundry. How can I start slaves in different machines?
While that video uses CloudFoundry, the premise of how it works applies off CloudFoundry as well. In that video I launch multiple JVM processes (web apps in that case). Some are configured as slaves so they listen for work. The other is configured as a master and he's the one I use to do the actual launching of the job.
Off of CloudFoundry, this would be no different than deploying WAR files onto Tomcat instances on multiple servers. You could also use Spring Boot to package executable jar files that run your Spring applications in a web container. In fact, the code for that video (which is available on Github here: https://github.com/mminella/Spring-Batch-Talk-2.0) can be used in the same way it was on CF. The only change you'd need to make is to not use the CF specific connection factories and use traditional configuration for your services.
In the end, the deployment model is the same off CloudFoundry or on. You launch multiple JVM processes on multiple machines (connected by middleware of your choice) and Spring Batch handles the rest.
I am developing a spring boot application.
Since spring boot created a .jar file for an application.
I want to cluster this particular application on different server. Lets say I build a jar file and ran a project then it should run in cluster mode from number of defined servers and should be able to serve end user needs.
My jar will reside on only one server but it will be clustered across number of servers. When end user calls a web service from my spring boot app he never know from where it is getting called.
The reason behind clustering is suppose any of the server goes down in future, end user will still be able to access web services from another server. But I don't know how to make it clustered.
Can any one please give me insight on this ?
If you want to have it clustered, you just run your Spring Boot application on multiple servers (of course, the JAR must be present on those servers, otherwise you can't run it). You would then place a loadbalancer in front of the application servers to distribute the load.
If all services you are going to expose are stateless so you only need to use load balancer in front of your nodes for ex. apache or nginx, if your services are stateful "store any state [session, store data in db]" so you have to use distributed cache or in memory data grid:
for session you can use spring-session project which could used rails to store sessions.
for store data in DB you need to cluster DB it self and can use distributed cache above your DB layer like Hazelcast.
Look into spring cloud, they have used some netflix open software along with amazons to create 12 factor apps for micro services.
Ideally you would need a load balancer, service registry that can help you achieve multiple instances of spring boot. I believe you have to add a dependency called eureka.
Check the below link
Spring cloud
You can deploy it in cloud foundry and use autoscale function to increase your application instances.
We are developing an application which periodically syncs the LDAP servers of different clients with our database. This application needs to be accessed via a web portal. A web user will create, modify or delete scheduled tasks on this application. So, we have developed this application as a web service.
Now, we have to scale this application and also ensure high availability.
The application is an Axis2 based web service running on Tomcat. We have thought of httpd + mod_jk + tomcat combination for load balancing. The problem is that if a request for modification/deletion comes, then it should land on the same tomcat server on which the task was created initially. But, since, the request can come from different web users accessing web portal from different ip addresses, we can not have same session id (sticky session).
Any solutions? Different architecture? Anything.
We have also thought of using Quartz scheduler api. The site says it supports load balancing and clustering. Does anyone has experience of working on such scenario with Quartz?
If you are using Quartz for your scheduling, that can be backed by a database (see JDBCJobStore). Then you could access any Tomcat server and the scheduling would be centralized. I would recommend using a key in the database that you return back to the Axis service, so that the user can reference the same data between calls.
Alternatively it is not difficult to use the database as a job scheduler, then have your tasks run on Tomcat (any location), and put the results into the database. If the results of the job (such as its status) are small, this would work fine.
I have a Websphere Cluster Setup v7. Server A1 Load Balancer, A2 (deployment Manager), B(WAS) , C(WAS). In server B and C ejb,web and a spring application is deployed. Spring application listens to a folder and when a file comes to that folder it processes it and then calls the web application via web services. So when spring application is deployed in B and C. Files are processed twice resulting in duplicate records how to tackle the above problem. Should i write a java logic or any setting in websphere will do things right ?? If i have to write a java logic pls give some suggestion (reliable and easily to implement NOTE: Cluster node can increase after some times).
Thanks
So, you have application logic using Spring, and the application logic misbehaves when it is run multiple times on the same filesystem. Is that correct? If so, there's nothing WebSphere Application Server can do. I suggest storing the state (whether the file has been processed) in shared storage, such as a database.