I would like to start an udp service in the backend (and not in the frontend) context (especially only once, because only one service can establish the socket, not both).
How can I figure out, in which context my bean is located, to open the port in one of both only?
Thanks in advice for any ideas
Greez
Related
I've been reading through the nameko docs, and it is all good and clear, except for one part.
How do you actually deploy your nameko microservice?
I mean, it is clear how we deploy RESTful APIs in flask_restful, for instance. But with nameko?
If two microservices should communicate, how do we move them into the "listening" state?
I am not sure I understand your problem.
For each nameko service you define AMQP_URI constant that point to your RabbitMQ instance.
If each of your services have the same AMQP_URI, it make possible communication through sending rpc calls (where you have a queue per service endpoint) or using pub/sub messaging because service use the same RabbitMQ instance.
You can also have HTTP REST API. You must define endpoint in nameko service with http decorator (see example here: https://nameko.readthedocs.io/en/stable/built_in_extensions.html). In your confguration you have to define PORT for you web server, e.g. port 8000: WEB_SERVER_ADDRESS: 0.0.0.0:8000. And make this port accessible for the World.
I am trying to achieve a result using Spring. In my case; I need to connect to a queue on n (~6) different hosts/ports. Say,
jms://hostA:portA/Queue
jms://hostB:portB/Queue
jms://hostC:portC/Queue
...
I am completely lost on where to start now. Reading tons of documents and it broke my whole motivation.
p.s; All the examples and documentations are mostly focused on ActiveMQ which in my case is not valid.
I do not need any code sample but a light on my way to start from. Like a some class names to check etc..
The JMS provider is irrelevant.
You need a connection factory bean for each host and configure each component (JMS template, listener container, etc) to use the appropriate connection factory.
I am in a situation where I have a microservice environment but for one service I want that it should not be load balanced rather work in a active standby(one at a time serves the request). When one service instance goes down then only the requests should be routed to the other instance even if the first one comes up the 2nd instance should be the one servicing the requests.
I am looking for the options like - overriding ribbon's IRule or doing this in a #PreFilter which is there on each of these services.
Let me know if anyone has any implementation for the above case.
I am developing a REST service which will connect to a CTI server through TCP and the connection will be kept opened until the my REST service is running.
Currently I am reading the server parameters from properties file and creating bean, after the bean is constructed, the server connection will be initiated using #PostConstruct. Is it good to use #PostConstruct for this scenario or should I use context refresh event.
I tested application using both #PostConstruct and context refresh, both are working good how ever I want to follow the best practices.
Note : I searched the forum and got some answers, but not related to my scenario
Technically there is no difference. You have already tested that part. I think #PostConstruct makes more sense mainly because the connection you are creating is specific to this bean. Creating a new ApplicationContextListener wouldn't make much sense as the connection is not at a context level.
Need to call a EJB service from the servlet context listener's contextInitialized() method. Application is running on JBOSS, though the context listener works fine, I'm not able to access the EJB bean through JNDI look up.
Because the web deployment in JBOSS happens before EJB beans are bound with JNDI tree. How to overcome from this? Is there a way to configure JNDI bind early or start the web deployment later once EJB's are completely deployed?
I had put Thread.sleep() before the service call in the contextInitialized() method, it is working fine in my JBoss5.1.0 GA, and the same did not work in other machines JBoss of same version.
Applications needs this because, we want to load some master data from the DB and make it available in the web layer (kind of caching). Does JBOSS startupmbean suit this requirement? If yes how can I make the data available to web layer?
Also if any alternative ways are available, please suggest.
Poll for the EJBs in contextInitialized(). So instead of just sleeping for a certain time, try to connect to the EJB. If that fails, sleep, and retry, until the EJBs are available. In this case the context initialization is blocked.
Implement the cache as a lazy one: Fill the cache during the first query (and use the same polling procedure: connect to the EJB, retry until it becomes available). In this case the cache blocks.
You could split your deployment into two parts: One for the EJBs, one for the web application. Then deploy the first, and delay deployment of the web application until the EJBs are bound (either by watching the log file or by trying bind to the EJB from a command line app)