how to connect to rabbitmq server with web proxy. I have rabbit credentials in application.yml spring.rabbitmq.host, spring.rabbitmq.port, spring.rabbitmq.username, spring.rabbitmq.password
I am not pretty sure what do you need but pls read below basic info:
The RabbitMQ is divided into 2 parts:
The Queue Service itself
The Management UI
You can install 1 without 2 or both.
The service works on port 5672 (and it is not HTTP) whereas Management UI on port 15672 (and it is HTTP).
Be aware that to connect to Management UI (via the browser) you need to have management plugin installed or use docker image with "management" postfix.
To sum up:
Your spring-boot application connects over port 5672 with the service directly.
If you have performed the steps mentioned before you should be able to connect to the management plugin using http://localhost:15672.
Related
I am new to the Microservices, I came across several concepts like Service Registry and Load Balancing. I have following questions-
How multiple instances of a particular microservice are created?
How Service Registry using Eureka Server helps in distributing the load on the several instances of Microservice?
In my scenario, I created 3 different microservices and registered them on my service registry-
Service Registry Configuration-
server:
port: 8761
eureka:
instance:
hostname: localhost
client:
register-with-eureka: false #this will ensure that this service
#is not itself registered as a client
fetch-registry: false
Client Configuration-
eureka:
instance:
prefer-ip-address: true
client:
fetch-registry: true #true by default
register-with-eureka: true #true by default
service-url:
defaultZone: http://localhost:8761/eureka
When I stop my services I still see the services as Up and Running on Eureka and get a warning as-
Can somebody please help me find the reason for this problem?
1. To communicate with another instance, you can use Eureka to find the address of the service you want to talk to. Eureka will give you a list of all the available instances of that service, and you can choose which one you want to communicate with.
2. The Eureka server is a microservice that keeps track of the locations of other microservices within the same system. These other microservices register themselves with the Eureka server so that they can be found and contacted by other microservices when needed. The Eureka server acts as a directory for the microservices, allowing them to find and communicate with each other. (not sure if that's what you asked).
3. In order to remove the warning:
You can set a renewal threshold limit in the Eureka server's properties file.
eureka.renewalPercentThreshold=0.85
1. To scale your microservice locally, you can run multiple instances of your Spring Boot application each on a different port.
First update the port on the microservice you wish to scale in the application.yml file to:
server:
port: 0
This will start the application on a random port each time you run it.
If you run 2 applications now, you will see 1 instance of your microservice on your Eureka dashboard. This is because they both have the same Eureka instance id. To fix this you need to generate a new instance id so add the below in the same application.yml:
spring:
application:
name: "hotel-service"
eureka:
instance:
instance-id: "${spring.application.name}:${random.value}"
Finally, just run the same application more than once. You can do this on InteliJ by right clicking on the main class and selecting run and then doing that again. Some extra setup may be required to run multiple instance of the same application on IntelliJ, please see link: How do I run the same application twice in IntelliJ?
If you are using Eclipse/STS, right click on project > Run as > Spring Boot App (do this twice or more).
Alternatively if you have maven installed. Open a terminal and run mvn spring-boot:run and then open a new terminal and run the command again.
Now you should see multiple instances of your application on the Eureka dashboard.
Note: In production scaling up a microservice is done on the by the Devops team, for example a container orchestration platform such as Kubernetes can be used to increase the instances of a microservices.
2. Generally an API gateway is used to route incoming network requests to microservices and do the load balancing while service discovery allows microservices to find and communicate with each other.
With Eureka service discovery, the microservices will register on the discovery server. An API gateway will also register on the Eureka server and will do load balancing.
One method of load balancing is the round-robin strategy, where the load balancer will rotate through the available instances in a sequential order. This helps to distribute the load evenly across the instances. There are also other load balancing methods, like Least Connection, Resource Based (Adaptive) etc.
3. The error your getting is due to the self preservation mode which comes with the Eureka server. The Eureka server expects a heartbeat from microservices every 30 seconds by default, if it doesn't receive a heartbeat within 90 seconds it will de-register a microservice from it. In a case where Eureka doesn't receive heartbeat signals from many services, it will de-register each microservice up to a certain limit. Then after it will enter self preservation mode and will not de-register any more microservices and will try to re-establish a connection, this is because a network issue could result in eureka server from not receiving heartbeats.
Since you are developing locally and you stopped running your microservices, you are seeing the expected behaviour of the Eureka server entering self preservation mode, which you can ignore.
You already register the microservices in eureka server.
Just run same service [hotel-service, rating service] on different port. Eureka server check name while registering microservice if It found same name It registered microservice with different {ip-address:port} format, you can also use same approch for load balancing
I am currently trying to setup service discovery with eureka, but the clients register with the wrong port. Every Eureka client is on a different server behind its own nginx reverse proxy and it is reachable from outside via https on port 443, but the java eureka clients are configured on different port. I also tried configuring them on the same port as nginx exposes, but than the nginx server has infinited redirects and stops after some attempts with error "invalid redirect". Being on different port the eureka clients register at the server with the port configure in spring boot yaml server port config. If then a client tries to reach another client it uses the port configured in the spring boot application. I need to be able to register the eureka client on a different port than I am running the client. Is that possible? What am I missing here? Would be using Zuul as a gateway make a difference here?
Setup (every system is deployed on a different VServer behind NGINX reverse proxy):
Eureka Server
Multiple Eureka Clients (API, UI, etc)
Identity Management Keycloak SSO server not registered with eureka server
A port can only be used by one service at a time. Hence, you cannot configure nignx and spring boot to listen on the same port and receive the error message.
Spring boot does not know about the proxy setup and hence the eureka client registers the instance (with the spring.port) at the eureka server. You can configure the eurka instance with the EurekaInstanceConfig. In this case you want to change eureka.instance.port=443 to the one exposed by nginx.
Whenever I deploy a spring boot app , it had embedded tomcat container. It relys on container being available. Does it mean that these are not 12 factor app compliant as depends on runtime injection of webserver?
What does TCP routing mean for non-http services?
Port Binding
Export services via port binding. The 12-factor app is
completely self-contained and does not rely on runtime injection of a
web server into the execution environment to create web-facing
service.
For Pivotal Cloud Foundry, non-HTTP services require TCP routing in
order to be replatformed.
When you run locally, a spring boot app, it runs with a default profile. So, Spring will leverage your port and other settings at runtime.
When you push to cloud, a spring boot app runs with a cloud profile. In a cloud profile, port settings are dictated by the cloud and settings you provide are ignored.
In PCF, a Diego cell hosts all app instances. A Diego cell has its own CIDR block for apps its hosting. So your app instance will get an IP from that range. And you cannot access the app by its ip.
The Diego cell vm though, has the IP from the CIDR range of the network its running. Diego cell also uses NAT-ing to map you app ip to a port on the Diego cell vm. That is how the traffic is routed to your app.
As you can see, the Diego cell, in PCF, cannot rely that the port you provided. Instead it will run the app where it can, and NAT to an available port.
Take a look at Diego Reference Architecture.
As to your second question, Go-Routers in Cloud Foundry route requests to app instances. By default only http/https traffic is enabled on Go-Routers. You can enable TCP Routing on Go-Routers. This was added, I believe, in PCF 1.9.
Here's the documentation.
Note: I am not using Pivotal CF.
I have a java application deployed on CloudFoundry. I am using embedded Jetty to host my Jersey REST API. This API is by default exposed on port 8080 by cloud foundry.
My application also needs some websockets to stream data to the browser. I am using Java-WebSocket (https://github.com/TooTallNate/Java-WebSocket) for this. On my local machine, I was using port 8887 for my websocket connection. Everything worked fine.
After deploying on CloudFoundry, I can access my REST API but not my websocket. After searching a bit online, I found that websocket connections are only allowed on port 4443 (http://docs.run.pivotal.io/release-notes/)
I changed my server side to reflect this
import org.java_websocket.server.WebSocketServer;
public class MyWebSocket extends WebSocketServer {
public MyWebSocket() throws UnknownHostException {
super(new InetSocketAddress(4443));
}
#Override
public void onOpen(org.java_websocket.WebSocket websocket, ClientHandshake handshake) {
// Handle this
}
}
On my client side, I am connecting the websocket using the following
wss://my_cf_app.com:4443/
But I am getting the following exception.
WebSocket connection to 'wss://my_cf_app.com:4443/' failed:
Establishing a tunnel via proxy server failed
I also tried to connect the websocket on server side using "PORT" environment variable of CF but I get "Address already in use" error in Java-WebSocket.
I have tried many different things but I am unable to figure this out. Any help would be awesome.
After deploying on CloudFoundry, I can access my REST API but not my websocket. After searching a bit online, I found that websocket connections are only allowed on port 4443 (http://docs.run.pivotal.io/release-notes/)
Port 4443 is specific to Pivotal Web Services (and some installs of CF that run on AWS). Most PCF installs do not have a separate port for WSS, but just use 443 along with the HTTPS traffic. The port used ultimately depends on the load balancer being used in front of the CF installation and what it supports.
You would never have your application listen on port 4443. Port 4443 is the external port for traffic where the load balancer listens. This traffic will be directed to the port assigned to your application, which is $PORT (env variable).
I also tried to connect the websocket on server side using "PORT" environment variable of CF but I get "Address already in use" error in Java-WebSocket.
This is the correct behavior, i.e. you should be listening on the port assigned through $PORT env variable. What the error is telling you is that something is already listening on this port and you cannot have two things listening on the same port.
There is only one port available per application at this time (likely to change in the future). For now, if you have two separate applications listening on two separate ports then you need to push them to CF as two separate applications.
What you can do to make them appear like one application to end users is to map each one to a specific path. See the --route-path argument of cf push or docs for cf create-route.
https://docs.cloudfoundry.org/devguide/deploy-apps/routes-domains.html#create-route
I need some help from someone who understands JBoss Hostname Binding. I think the solution is easy, although it's complicated to explain.
I am deploying an application using JBoss (v4.2) and am having troubles configuring the application.
This application has two parts, a web site on port 8080 and web services on port 8080 using SOAP APIs.
My server sits behind a firewall, and has an alias, let's say it's called orange.mycompany.com
My problem is that I cannot get the console to connect to the web services. The website works, but I see an connection refused error connecting to the web services.
[xfire.transport.http.HttpChannel]
java.net.ConnectException: Connection
refused
There are 2 things I can control, the bind IP on Tomcat, and the URL of the web services.
If I start JBoss, and bind to the local IP address:
./run.sh -b 10.1.2.3
And I set the URL of the web services to be that same IP
url=http://10.1.2.3:8080/services
I can see the website on port 8080 from outside the firewall, but the console cannot connect to webservices.
From the server, orange, itself I cannot see the website by calling http://localhost:8080/ or http://10.1.2.3:8080 or orange.mycompany.com:8080
However, if I start JBoss and bind to 127.0.0.1:
./run.sh -b 127.0.0.1
And I set the URL of the web services to localhost
url=http://localhost:8080/services
Now I can't see the website at all from outside the firewall.
But from the server itself, I can see the website browsing http://localhost:8080 and the I can successfully connect to the web services. That's great, but I need the website to be accessible from outside.
Can anyone suggest any combination of settings that will let me browse the website and also let the console call webservices on localhost?
Never mind.
Start JBoss binding to all IP's works.
./run.sh -b 0.0.0.0
Aren't your running JIRA standalone, right?
I always run tomcat and jboss behind a apache with mod_jk. This still hide ports, what sounds great for newbies users.
Your server is behind a NAT?
Sometimes I use ProxyPass or RewriteRules (mod_rewrite) to provide external access, thru reverse proxy.