I am testing spring zuul. I want to test round-robin requests forward using zuul routes. And not using eureka setup.
zuul.ignoredServices=*
ribbon.eureka.enabled=false
server.port=9000
zuul.routes.trackingv1.path=/tracking/v1/**
zuul.routes.trackingv1.stripPrefix=false
zuul.routes.trackingv1.serviceId=trackingv1
trackingv1.ribbon.listOfServers=http://localhost:8080/trackingv1,http://localhost:8081/trackingv1
But I am getting errors like Caused by: com.netflix.client.ClientException: Load balancer does not have available server for client: trackingv1
Any idea, what could be wrong?
It's same old problem with using properties. (extra space in value part of key). I had extra space in
zuul.routes.trackingv1.serviceId=trackingv1<space>
Now next problem is, from list of servers
trackingv1.ribbon.listOfServers=http://localhost:8080/trackingv1,http://localhost:8081/trackingv1 it is picking online host:port portion. How to add contextPath "trackingv1" ?
Related
I have deployed NiFi with Kerberos in a cluster and for accessing the UI I am using haproxy. I am able to access NiFi UI through the individual node URL but it's not working with the loadbalncer URL and getting following error
System Error
The request contained an invalid host header
I think it can be fixed by nifi.web.proxy.host and nifi.web.proxy.context.path parameters. I tried with this two parameters but the problem still remains.
This issue was pointed at in NiFi 1.5 NIFI-4761.
To resolve this issue, whitelist the hostname used to access NiFi using the following parameter in the nifi.properties configuration file :
nifi.web.proxy.host = <host:port>
Its a comma-separated list of allowed HTTP Host header values to consider when NiFi is running securely and will be receiving requests to a different host[:port]. For example, when running in a Docker container or behind a proxy (e.g. localhost:18443, proxyhost:443). By default, this value is blank, meaning NiFi should allow only requests sent to the host[:port] that NiFi is bound to.
I have react frontend and spring boot backend with mongodb behind.
I have issues with setting 2 parameters in the spring boot service.
First is address of the mongodb which is now set as localhost:27017 in the application.properties
It works at localhost but since I plan to scale out using kubernetes and docker images i would like to know how to define
It and where for the case in which I have mongo1 mongo2 and mongo3 database hosts and would like to pass all 3 URIs ?
Second issues is more tricky! React frontend doesnt work in chrome until I put allow cross origin anotation over my spring rest endpoint . I used hardcoded localhost:3000 here but when I scale it out using kubernetes this wont work if it gets data from another host in the cluster.What to do here?
To answer your first question, you can configure multi data sources, see here documentation how you can configure more than one data sources (80.2 Configure Two DataSources.
For second question you can simply wildcard CORS URL or if you know all of your front end server urls which are load balanced you can pass as list of cors url.
– * – means that all origins are allowed.
– If undefined, all origins are allowed.
RECOMMENDATION
Run your react via yarn to deploy on Apache or ngnix. Once you seted up your domain or sub domain for front end, load balanced your front end so not required to run your front end on ports..
Environment
Spring Boot 1.5.13.RELEASE
Spring Cloud Edgware.SR3
Java 8
Configuration
Eureka client is enabled and working correctly (I have tested and everything's working as I expect).
Some relevant properties from my configuration:
feign.hystrix.enabled=true
eureka.client.fetch-registry=true
spring.cloud.service-registry.auto-registration.enabled=true
service1.ribbon.listOfServers=https://www.google.com
Context
I have an application which speaks to 3 other services using feign clients. Two of these are discovered via Eureka service discovery. These are working well. The final service is an external one with a single static hostname and I do not want this resolved via Eureka. Since I do want Eureka for 2 of these services I would like to keep Eureka enabled.
Question
For the final service I tried adding service1.ribbon.listOfServers=https://www.google.com to the application.properties, however this cases the following error at runtime when invoking the feign client:
Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is com.netflix.hystrix.exception.HystrixRuntimeException: Service1Client#test() failed and no fallback available.] with root cause
pricing_1 |
pricing_1 | com.netflix.client.ClientException: Load balancer does not have available server for client: service1
pricing_1 | at com.netflix.loadbalancer.LoadBalancerContext.getServerFromLoadBalancer(LoadBalancerContext.java:483) ~[ribbon-loadbalancer-2.2.5.jar!/:2.2.5]
My client is configured as follows:
#FeignClient("service1")
public interface Service1Client {
#GetMapping(value = "/")
String test();
}
Thanks in advance for any advice.
Consideration
Since the spirit of Ribbon as I understand it is to act as a client side load balancer and given in my case there is nothing to load balance (I have one fixed static hostname that returns a single A record in DNS). Ribbon actually feels like an unnecessary component - what I really wanted was the Feign client as I like the fact that it abstracts away the lower level HTTP request and object seralization. So I suppose an alternative follow up question is, can I use feign without ribbon - it seems the nice out of the box behaviour would be to use ribbon - even the Javadoc of the #FeignClient annotation says:
If ribbon is available it will be
used to load balance the backend requests, and the load balancer can be configured
using a #RibbonClient with the same name (i.e. value) as the feign client.
suggesting the two are quite closely related even if they are serving different purposes.
As you mentioned, there are two ways to solve your problem.
Use Feign without Ribbon
If you specify url attribute in #FeignClient annotation, it will work without Ribbon like the below.
#FeignClient(name = "service1", url = http://www.google.com)
public interface Service1Client {
#GetMapping(value = "/")
String test();
}
In this case, your other two Feign client will still work with Ribbon and Eureka.
Use Feign with Ribbon and without Eureka
What you are missing is in your configuration is NIWSServerListClassName.
Its default value is com.netflix.niws.loadbalancer.DiscoveryEnabledNIWSServerList and it will use Eureka to retrieve the list of server. If you set NIWSServerListClassName to ConfigurationBasedServerList for a ribbon client (feign client), only that client will work with listOfServers list without retrieving server list from Eureka. And other feign clients will still work with Eureka.
service1:
ribbon:
NIWSServerListClassName: com.netflix.loadbalancer.ConfigurationBasedServerList
listOfServers: http://www.google.com
I am working on a flow where I have ng4+boot app running on https://host_a:8080 and a backend service at https://host_b:8080 with some APIs.
I have RestController/Path at both the hosts, i.e. I need some urls to hit localhost (host_a) and others to host_b.
In application.yml, I have tried almost all possible combinations of Zuul routes but still getting 404 for all host_b rest APIs. host_a APIs work well.
Note: We have this working when there is no rest API on host_a and no custom filter on host_a.
Is there something wrong working with filter? I don't see any log from zuul filter now after I added this controller to host_a
I am aware that I can use forward property to route to localhost which works well. But somehow host_b rest all gives 404 error.
My implementation requirements-
http://host_a:8080/api/abc/user to hit at localhost i.e. host_a
http://host_a:8080/api/xyz/getall to hit at host_b
Important- Need a custom zuul filter which adds certain headers to request before it's routed to host_b as explained in point 2. - Already at place, but cannot see logs inside it now.
What I tried already-
zuul:
routes:
xyz:
path: /api/xyz/**
url: http://host_b:8080/api/xyz
I tried almost everything, using prefix, strip-prefix, only host in url, using forward for local routing, etc. Nothing works.
Kindly help me with the possible causes I may be ignoring or if missing something?
Thanks in advance.
Finally, I was able to resolve issues.
1. I had to change jersey #Path to spring #RestController
2. Changed Zuul Filter order from 1 to 999.
Works well now.
I just tried to do a attempted a seamless upgrade of a service in a test setup. The service is being accessed by a Feign client. And naively I was under the impression that with multiple instances available of the service, the client would retry another instance if it failed to connect to one.
That, however, did not happen. But I cannot find any mention of how Feign in Spring Cloud is supposed to be configured to do this? Although I have seen mentions of it supporting it (as opposed to using RestTemplate where you would use something like Spring Retry?)
If you are using ribbon you can set properties similar to the following (substituting "localapp" for your serviceid):
localapp.ribbon.MaxAutoRetries=5
localapp.ribbon.MaxAutoRetriesNextServer=5
localapp.ribbon.OkToRetryOnAllOperations=true
ps underneath Feign has a Retryer interface, which was made to support things like Ribbon.
https://github.com/Netflix/feign/blob/master/core/src/main/java/feign/Retryer.java
see if property works - OkToRetryOnAllOperations: true
You can refer application ->
https://github.com/spencergibb/spring-cloud-sandbox/blob/master/spring-cloud-sandbox-sample-frontend/src/main/resources/application.yml
Spencer was quick...was late by few minutes :-)