I'm new to Hystrix and I just created my first Hystrix Commands. The commands are being created and executed in a loop so the metrics data should have being registered. I am using the servo metrics publisher as follows:
HystrixPlugins.getInstance()
.registerMetricsPublisher(HystrixServoMetricsPublisher.getInstance());
EDIT:
Looking at the JConsole I found the related metrics definition as follows in the link:
jconsole
I am not using spring, eureka, servo to read data and run the app.
I would like to know how to expose this data in a way that prometheus can read. I tried hystrix-prometheus, but the documentation is not helpful when it is about where the metrics are being exposed, how to get them or check the them.
In order to retrieve Hystrix metrics, you'll first need to get Prometheus' Java Simple Client up and running. The setup depends on your environment. Independent of your environment the result should be a URL where you can retrieve i.e. simple Java metrics.
Once that it up and running, you can use the line
HystrixPrometheusMetricsPublisher.register("application_name");
to register the additional Hystrix metrics. They will be served by the same URL. Please note that you will see Hystrix metrics only after the first call of a Hystrix enabled command.
Related
I have this SpringBoot server app using PostgreSQL database if it's up and sending error response if it's down. So my app is running regardless the database connection.
I would very much like to test it (jUnit / mockmvc).
My question is very simple, yet I did not find the answer online:
how does one simulate a database connection loss in SpringBoot?
If anyone wants, I can supply code (project is up at https://github.com/k-wasilewski/workshop/)
Have you thought of Testcontainers? You can spin up your docker image through a Junit test and make your spring boot use that as your database.
Since you use junit, you can start/stop this container at will.
This will generate a test which creates the condition you are looking for and write code as to what to expect when the database is down.
Here are some links to get started,
Testcontainers and Junit4 with Testcontainers quickstart - https://www.testcontainers.org/quickstart/junit_4_quickstart/
Spring boot documentation - Use Testcontainers for integration testing
https://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#howto-testcontainers
Testcontainer github link example for springboot app
https://github.com/testcontainers/testcontainers-java/tree/master/examples/spring-boot
Testcontainer - Generic container javadoc. You can find methods for start/stop
container here. call from your Junit.
https://javadoc.io/static/org.testcontainers/testcontainers/1.12.4/org/testcontainers/containers/GenericContainer.html
You can implement your own Datasource based on DelegatingDataSource and then let it throw exceptions instead of delegating when ever you want to.
I've done this before by creating a Spring Boot test configuration class that created the DataSource and wrapped it in a Java proxy. The proxy simply passed method calls down to the underlying DataSource, until a certain flag was set. Once the flag was set, then any method called on the proxy would throw an exception without calling the underlying DataSource. Essentially, this allowed me to "bring the database down" or "up" simply by flipping the flag.
I want to check latencies of RPC every day about CakePHP Application each endpoints running in GKE cluster. I found it is possible using php google client or zipkin server by reading documents , but I don't know how easy to introduce to our app though both seem tough for me.
In addition, I'm concerned about GKE cluster configuration has StackDriver Trace option though our cluster it sets disabled.Can we trace span if it sets enable?
Could you give some advices?
I succeeded to send gcp's trace api in php client via REST. It can see trace set by php client parameters , but my endpoint for trace api has stopped though I don't know why.Maybe ,it is not still supported well because the document have many ambiguous expression so, I realized watching server response by BigQuery with fluentd and DataStudio and it seem best solution because auto span can be set by table name with yyyymmdd and we can watch arbitrary metrics with custom query or calculation field.
I have 2 Spring apps ("client-app" and "service-app") that are already registered to Eureka (and talk via Feign Client). However, I have to talk to an instance of Solr and I'm forced to hard-code the IP address in the properties file. I would much rather not do this and use Eureka for service-discovery.
Question: Is there a way/plugin to have solr register itself with Eureka, so that clients can then discover it (even if it's programmatically via a start-up listener or some sort)?
I've looked at the solr API and it doesn't seem to have lifecycle listener (onStartUp or onShutdown hooks)
You would need a Solr Plugin for this, which is SolrCore aware. That interface method inform is called anytime something interesting happens with a core. Within the implementation of the inform method you would need to register/deregister as a client.
Then you would need to add it to your Solr (Cloud) instance. After that and proper configuration of your plugin, it should work.
I am developing an application and decided Nagios3 for performing monitoring stuff. But I am stuck at two points. I am using check_http plug-in for monitoring load on my service api. Now I want to perform below tasks.
I need to set a threshold in check_http for performing some task after crossing that threshold. I tried below command
'check_command check_nrpe_1arg!check_service_api'
but it only tells me the load, not any threshold is set. while below one doesn't work.
'check_command check_service_api!100!200'
I need to send simple text message on some port(my application).
I am new to Nagios, so please help me figuring out the solution except email notification stuff.
There is a check command that you can download called "notify_sms" that integrates with an API server hosted by a company called Esendex. They charge for their service but it works well.
How does one fire off a web request to icinga2 to set a service group into maintenance? Documentation is tough to find.
We frequently encounter false positive alerts during deployment (due to app-spinup) and would like to be able to programattically disable checking on service groups until deployment is finished.
There is no unified api yet (that's something we plan for 2.4 later this year). You should use the external commands for that - given that You must first fetch all servicegroup members and send a command ffor each I'd suggest using Livestatus. Details at http://docs.icinga.org/icinga2/latest/doc/module/icinga2/chapter/alternative-frontends#setting-up-livestatus