can anyone point me to a resource, how I can get spring-webflux and javamelody to work together?
Seems, that a servletcontext is neccessary for startup, which I don't have/need.
I'm aware of the coll metrics stuff, that comes with spring-boot 2.x, but I don't have anything to display the metrics with, and am locked to a company environment, where just installing something isn't a valid option.
Thanks,
Henning
javamelody is mainly based on monitoring of memory, cpu, http requests, sql requests and spring components among other things. See javamelody-spring-boot-starter for example.
But as far as I know, Spring webflux does not use the servlet api. So what do you want to monitor?
If you just want to have graphs in a browser, then start a http server for javamelody reports like in standalone. And if you also want to monitor sql requests and spring components, then add in your application all methods from this example, except monitoringSessionListener and monitoringFilter.
A new spring-boot-starter for javamelody in webflux could be created if it makes sense.
Related
I have a client-server based microservice architecture. i.e, a server-config(Spring cloud config) service that has all the configurations and properties that are fetched using jdbc Backend-(PostgreSQL in my case) along with profiling.
I wanted to understand that incase of failure of my server-config service are there any chances of the rest of the dependent services to fail as they will no longer be able to fetch the required properties from the server-config service? If yes, then how can I mitigate this issue.
I could think of implementing cache but will have to go through the steps required to do so. Can someone help me clear out the above scenario.
wanted to try some new stuff and decided to build next micro-app in Ktor + Koin + Exposed. Everything looks really nice but I found one problem that is actually destroying the whole idea.
App needs DB access and the connection cannot be stored within repository but should be encrypted on config-server. Every other micro-app is suing spring boot and fetches configs with lib spring-cloud-config-client but I don't know if it's even possible to use that somehow from Ktor app. Anyone had the same problem and managed to fix it somehow?
Cfg4j seems to be an alternative to Spring Cloud Config Server.
https://github.com/cfg4j/cfg4j
Other than that, there are a few articles and some questions on SO about integrating Spring Cloud Config Server with non Spring Boot projects.
Spring Cloud Config Client Without Spring Boot
Also, I am working on an external configuration parser for Kotlin and am considering to implement similar functionality.
I have a spring boot project with websocket and I want to test the project sending multiple request to the socket from different users. I want to use threads to imitate the users that send data from the web app but I don't know exactly how to make the test. Can anyone help me, and show one simple test for an websocket using threads?
You can use JMeter for testing your websocket project.
For further reading:
https://www.blazemeter.com/blog/websocket-testing-apache-jmeter
http://www.baeldung.com/websockets-spring
Good example:
https://github.com/Fyro-Ing/JMeter-WebSocket-StompSampler
When writing a Spring Boot application using STOMP on websockets, I struggled a lot to find out how to configure a test client.
I ended up writing a little library called Jackstomp to make it easier to create type-safe tests for STOMP WS applications using JSON as message body.
I haven't used it with multiple threads, but you should be able to easily use it within each thread to create independent clients for each user and perform basic operations. (Please note that a different client should be used in each thread).
The point is that you can really express a synchronous flow for each client, including actively querying for received events.
Even if you don't use this library, you can look at the code to get a grasp of the different things to setup.
I'm designing a software system which has some C++ projects and java web applications hosted on Apache/Tomcat. Native code[C++ outputs] will connect to other systems[DB, External Gateways, etc] through web apps as HTTP requests. In order to make a good distributed/modular system, I'm planning to use several [5 to 10] web applications.
But still my system is not finished its developments, but function enough to sell. But even still 20% of its full features, I have to go through a huge deployment procedure since it has much of web apps.
My question is,
Is it good to merge few web apps TEMPORARILY to reduce deployment overhead[I can do this till I get a significant larger source for each] and do http requests within that same web application?
Will it be cause any performance/memory/threading issue?
if you are merging two or three web components and want to deploy an single jvm
than you should not use http request between web components,
for this you can use jboss osgi http://www.jboss.org/jbossas/subprojects/osgienter link description here
The solution I found was to use a hosted JVM, which is an application on either a Servlet container or in a web service.
This way, a single JVM is re-used.
But the problem here is that, you need a communication mechanism between two applications, which I prefer of using TCP sockets.
I am working on a project which has following requirements:
Perform sticky based load balancing(based on SOAP session ID) onto multiple backend servers.
Possibility to plugin my own custom based load balancer.
Easy to write and deploy.
A central configuration file(Possibly an XML), to take care of all the backend servers.
Easy extraction of a node from this configuration file(Possibly with xpath).
I tried working with camel for a while but, wasn't able to do perform certain task with it.
So thought of giving a try to Akka.
Will akka be possibly able to satisfy the above requirements?
If so is there a load balancing example in akka or proxy example?
Would really appreciate some feedbacks.
You can do everything you've described with Akka.
You don't mention what language you're working with, Scala or Java. I've included links to the Scala documentation.
Before you do anything with Akka you HAVE TO read the documentation and understand how Akka works.
http://doc.akka.io/docs/akka/2.0.3/
Doing so, you'll find Akka is perfect for the project you've described with some minor caveats.
Once you read the documentation the following answers should make a lot of sense.
Perform sticky based load balancing(based on SOAP session ID) onto multiple backend servers.
Load balancing is already part of the framework (it's called Routing in Akka http://doc.akka.io/docs/akka/2.0.3/scala/routing.html) and Remoting (http://doc.akka.io/docs/akka/2.0.3/scala/remoting.html) will take care of the backend servers. You can easily combine the two.
To my knowledge the idea of sticky load balancing is not a part of Akka but I can envision this being accomplished with a Map using the session ID as the key and the Actor name (or path) as the value. A quick actorFor will take care of the rest. Not well thought out but should give you a good idea of where to start.
Possibility to plugin my own custom based load balancer.
Refer to the Routing documentation.
Easy to write and deploy.
This depends on your aptitude and effort but after you read certain parts of the documentation you should be build a proof of concept in a couple of hours.
Deployment can be a bit frustrating mostly because the documentation isn't really great with respect to deploying Akka networks with remote components. However, there are enough examples on the web that you can figure out how to get it done...eventually. Once you do it once it's no big deal.
A central configuration file(Possibly an XML), to take care of all the backend servers.
Akka uses Typesafe Config (https://github.com/typesafehub/config) which is a lot easier to work with than XML (but I hate XML so take that with a grain of salt). As far as a central configuration, I'm not sure what you're trying to accomplish but it sounds like something that can be solved using remote actor creation. Again, see the Remoting documentation.
Easy extraction of a node from this configuration file(Possibly with xpath).
Akka provides a lookup method .actorFor. There's no need to go to the configuration file once the system is up and running.
If so is there a load balancing example in akka or proxy example?
Google is your friend.