Develop programmatically a Jgroup Channel for Infinispan in a Cluster - caching

I'm working with infinispan 8.1.0 Final and Wildfly 10 in a cluster set up.
Each server is started running
C:\wildfly-10\bin\standalone.bat --server-config=standalone-ha.xml -b 10.09.139.215 -u 230.0.0.4 -Djboss.node.name=MyNode
I want to use Infinispan in distributed mode in order to have a distributed cache. But for mandatory requirements I need to build a JGroups channel for dynamically reading some properties from a file.
This channel is necessary for me to build a cluster-group based on TYPE and NAME (for example Type1-MyCluster). Each server who wants to join a cluster has to use the related channel.
Sailing the net I have found some code like the one below:
public class JGroupsChannelServiceActivator implements ServiceActivator {
#Override
public void activate(ServiceActivatorContext context) {
stackName = "udp";
try {
channelServiceName = ChannelService.getServiceName(CHANNEL_NAME);
createChannel(context.getServiceTarget());
} catch (IllegalStateException e) {
log.log(Level.INFO, "channel seems to already exist, skipping creation and binding.");
}
}
void createChannel(ServiceTarget target) {
InjectedValue<ChannelFactory> channelFactory = new InjectedValue<>();
ServiceName serviceName = ChannelFactoryService.getServiceName(stackName);
ChannelService channelService = new ChannelService(CHANNEL_NAME, channelFactory);
target.addService(channelServiceName, channelService)
.addDependency(serviceName, ChannelFactory.class, channelFactory).install();
}
I have created the META-INF/services/....JGroupsChannelServiceActivator file.
When I deploy my war into the server, the operation fails with this error:
"{\"WFLYCTL0180: Services with missing/unavailable dependencies\" => [\"jboss.jgroups.channel.clusterWatchdog is missing [jboss.jgroups.stack.udp]\"]}"
What am I doing wrong?
How can I build a channel the way I need?
In what way I can tell to infinispan to use that channel for distributed caching?

The proposal you found is implementation dependent and might cause a lot of problems during the upgrade. I wouldn't recommend it.
Let me check if I understand your problem correctly - you need to be able to create a JGroups channel manually because you use some custom properties for it.
If that is the case - you could obtain a JGroups channel as suggested here. But then you obtain a JChannel instance which is already connected (so this might be too late for your case).
Unfortunately since Wildfly manages the JChannel (it is required for clustering sessions, EJB etc) the only way to get full control of JChannel creating process is using Infinispan embedded (library) mode. This would require adding infinispan-embedded into your WAR dependencies. After that you can initialize it similarly to this test.

Related

Configuration Bean in Quarkus

This is regarding CDI spec of quarkus. Would want to understand is there a configuration bean for quarkus? How does one do any sort of configuration in quarkus?
If I get it right the original question is about #Configuration classes that can contain #Bean definitions. If so then CDI producer methods and fields annotated with #javax.enterprise.inject.Produces are the corresponding alternative.
Application configuration is a completely different question though and Jay is right that the Quarkus configuration reference is the ultimate source of information ;-).
First of all reading how cdi spec of quarkus differs from spring is important.
Please refer this guide:
https://quarkus.io/guides/cdi-reference
The learnings from this guide is there is #Produces which is an alternative to #Configuration bean in Quarkus.
Let us take an example for libs that might require a configuration through code. Example: Microsoft Azure IOT Service Client.
public class IotHubConfiguration {
#ConfigProperty(name="iothub.device.connection.string")
String connectionString;
private static final Logger LOG = Logger.getLogger(IotHubConfiguration.class);
#Produces
public ServiceClient getIot() throws URISyntaxException, IOException {
LOG.info("Inside Service Client bean");
if(connectionString==null) {
LOG.info("Connection String is null");
throw new RuntimeException("IOT CONNECTION STRING IS NULL");
}
ServiceClient serviceClient = new ServiceClient(connectionString, IotHubServiceClientProtocol.AMQPS);
serviceClient.open();
LOG.info("opened Service Client Successfully");
return serviceClient;
}
For all libs vertically intergrated with quarkus application.properties can be used and then you will get a driver obj for that broker/dbs available directly through #Inject in your #applicationScoped/#Singleton bean So, Why is that?
To Simplify and Unify Configuration
To Make Sure no code is required for configuring anything i.e. database config, broker config , quarkus config etc.
This drastically reduces the amount of code written for configuring and also Junits needed to cover that code.
Let us take an example where kafka producer configuration needs to be added: in application.properties
kafka.bootstrap.servers=${KAFKA_BROKER_URL:localhost:9092}
mp.messaging.outgoing.incoming_kafka_topic_test.topic=${KAFKA_INPUT_TOPIC_FOR_IOT_HUB:input_topic1}
mp.messaging.outgoing.incoming_kafka_topic_test.connector=smallrye-kafka
mp.messaging.outgoing.incoming_kafka_topic_test.value.deserializer=org.apache.kafka.common.serialization.StringDeserializer
mp.messaging.outgoing.incoming_kafka_topic_test.key.deserializer=org.apache.kafka.common.serialization.StringDeserializer
mp.messaging.outgoing.incoming_kafka_topic_test.health-readiness-enabled=true
For full blown project reference: https://github.com/JayGhiya/QuarkusExperiments/tree/initial_version_v1/KafkaProducerQuarkus
Quarkus References for Config:
https://quarkus.io/guides/config-reference
Example for reactive sql config: https://quarkus.io/guides/reactive-sql-clients
Now let us talk about a bonus feature that quarkus provides which improves developer experience by atleast an order of magnitude that is profile driven development and testing.
Quarkus provides three profiles:
dev - Activated when in development mode (i.e. quarkus:dev)
test - Activated when running tests
prod - The default profile when not running in development or test
mode
Let us just say that in the given example you wanted to have different topics for development and different topics for production. Let us achieve that!
%dev.mp.messaging.outgoing.incoming_kafka_topic_test.topic=${KAFKA_INPUT_TOPIC_FOR_IOT_HUB:input_topic1}
%prod.mp.messaging.outgoing.incoming_kafka_topic_test.topic=${KAFKA_INPUT_TOPIC_FOR_IOT_HUB:prod_topic}
This is how simple it is. This is extremely useful in cases where your deployments run with ssl enabled brokers/dbs etc and for dev purposes you have unsecure local brokers/dbs. This is a game changer.

Refresh springboot configuration dynamically

Is there any way to refresh springboot configuration as soon as we change .properties file?
I came across spring-cloud-config and many articles/blogs suggested to use this for a distributed environment. I have many deployments of my springboot application but they are not related or dependent on one another. I also looked at few solutions where they suggested providing rest endpoints to refresh configs manually without restarting application. But I want to refresh configuration dynamically whenever I change .properties file without manual intervention.
Any guide/suggestion is much appreciated.
Can you just use the Spring Cloud Config "Server" and have it signal to your Spring Cloud client that the properties file changed. See this example:
https://spring.io/guides/gs/centralized-configuration/
Under the covers, it is doing a poll of the underlying resource and then broadcasts it to your client:
#Scheduled(fixedRateString = "${spring.cloud.config.server.monitor.fixedDelay:5000}")
public void poll() {
for (File file : filesFromEvents()) {
this.endpoint.notifyByPath(new HttpHeaders(), Collections
.<String, Object>singletonMap("path", file.getAbsolutePath()));
}
}
If you don't want to use the config server, in your own code, you could use a similar scheduled annotation and monitor your properties file:
#Component
public class MyRefresher {
#Autowired
private ContextRefresher contextRefresher;
#Scheduled(fixedDelay=5000)
public void myRefresher() {
// Code here could potentially look at the properties file
// to see if it changed, and conditionally call the next line...
contextRefresher.refresh();
}
}

Mule connector config needs dynamic attributes

I have develop a new Connector. This connector requires to be configured with two parameters, lets say:
default_trip_timeout_milis
default_trip_threshold
Challenge is, I want read ${myValue_a} and ${myValue_a} from an API, using an HTTP call, not from a file or inline values.
Since this is a connector, I need to make this API call somewhere before connectors are initialized.
FlowVars aren't an option, since they are initialized with the Flows, and this is happening before in the Mule app life Cycle.
My idea is to create an Spring Bean implementing Initialisable, so it will be called before Connectors are init, and here, using any java based libs (Spring RestTemplate?) , call API, get values, and store them somewhere (context? objectStore?) , so the connector can access them.
Make sense? Any other ideas?
Thanks!
mmm you could make a class that will create the properties in the startup and in this class obtain the API properties via http request. Example below:
public class PropertyInit implements InitializingBean,FactoryBean {
private Properties props = new Properties();
#Override
public Object getObject() throws Exception {
return props;
}
#Override
public Class getObjectType() {
return Properties.class;
}
}
Now you should be able to load this property class with:
<context:property-placeholder properties-ref="propertyInit"/>
Hope you like this idea. I used this approach in a previous project.
I want to give you first a strong warning on doing this. If you go down this path then you risk breaking your application in very strange ways because if any other components depend on this component you are having dynamic components on startup, you will break them, and you should think if there are other ways to achieve this behaviour instead of using properties.
That said the way to do this would be to use a proxy pattern, which is a proxy for the component you recreate whenever its properties are changed. So you will need to create a class which extends Circuit Breaker, which encapsulates and instance of Circuit Breaker which is recreated whenever its properties change. These properties must not be used outside of the proxy class as other components may read these properties at startup and then not refresh, you must keep this in mind that anything which might directly or indirectly access these properties cannot do so in their initialisation phase or your application will break.
It's worth taking a look at SpringCloudConfig which allows for you to have a properties server and then all your applications can hot-reload those properties at runtime when they change. Not sure if you can take that path in Mule if SpringCloud is supported yet but it's a nice thing to know exists.

Spring boot embedded jettty thread pool maximum size

I want to configure Thread pool size for my application which is using spring boot embedded jetty server. Below is the code snippet i am using.
I want to know what is the maximum thread pool size I can set for the embedded jetty server and is it the correct way of configuring it?
#Bean
public EmbeddedServletContainerFactory jettyConfigBean() {
JettyEmbeddedServletContainerFactory jef = new JettyEmbeddedServletContainerFactory();
jef.addServerCustomizers(new JettyServerCustomizer() {
public void customize(org.eclipse.jetty.server.Server server) {
final QueuedThreadPool threadPool = server.getBean(QueuedThreadPool.class);
server.setHandler(handlers);
}
});
return jef;
}
Speaking for spring-boot 2.0.0-SNAPSHOT:
This is for jetty and tomcat and undertow configurable via
server.jetty.acceptors
server.tomcat.max-connections
server.undertow.io-threads
See https://docs.spring.io/spring-boot/docs/current-SNAPSHOT/reference/htmlsingle/#common-application-properties for a complete reference.
The maximum number of threads you can set is dependent on your machine, not so much on the hosting software. If you have a monster machine you can probably have hundreds of threads, whereas a regular laptop would probably only be able to handle tens of threads. You need to tune your configuration by testing. A good way is to setup a load test, for example see if 50 threads with 50 req/sec will crash your service, then check if increasing/decreasing the number of threads will help. You can find the limits of your application and machine with such a technique.
Regarding the correctness of the configuration, you can read this blog post which explains it very well: http://jdpgrailsdev.github.io/blog/2014/10/07/spring_boot_jetty_thread_pool.html
This is what you can do:
While working on newer versions, you need to create a server factory bean in a configuration file. I tested this on Spring Boot version 2.1.6 while the document I referred to is for version 2.3.3
#Bean
public ConfigurableServletWebServerFactory webServerFactory() {
JettyServletWebServerFactory factory = new JettyServletWebServerFactory();
factory.setPort(8080);
factory.setContextPath("/my-app");
QueuedThreadPool threadPool = new QueuedThreadPool();
threadPool.setMinThreads(10);
threadPool.setMaxThreads(100);
threadPool.setIdleTimeout(60000);
factory.setThreadPool(threadPool);
return factory;
}
Following is the link to Spring Docs: customizing-embedded-containers

Pre-bound JDBC Connection found

We have an app that is using hibernate, spring, and DB2 in websphere 7. We have audit triggers and we need to set so the triggers can know the logged in user (we use generic logon to the database). We came up with a new scheme for setting this in a new app so that it can automatically join in new transactions. We overrode the transaction manager and did the work in the doBegin.
These scheme worked great in one app, and seemed to work great in a second app, but now, weeks later, and not consistently (behavior is intermittent and does not happen in local development), we are getting this Pre-bound JDBC Connection found error. Looking online most posts say this is when you use two transaction managers against one data source. That is now what we are doing.
I also read one post wondering if it was because he mixed annotation and AOP based transactions. This app does some of that. I don't really buy that theory, but thought I'd mention it.
Exception:
Caused by:
org.springframework.transaction.IllegalTransactionStateException: Pre-bound JDBC Connection found! HibernateTransactionManager does not support running within DataSourceTransactionManager if told to manage the DataSource itself. It is recommended to use a single HibernateTransactionManager for all transactions on a single DataSource, no matter whether Hibernate or JDBC access.
at java.lang.Throwable.<init>(Throwable.java:67)
at org.springframework.core.NestedRuntimeException.<init>(NestedRuntimeException.java:54)
at org.springframework.transaction.TransactionException.<init>(TransactionException.java:34)
at org.springframework.orm.hibernate3.HibernateTransactionManager.doBegin(HibernateTransactionManager.java:475)
at gov.usdoj.afms.umc.utils.hibernate.AfmsHibernateTransactionManager.doBegin(AfmsHibernateTransactionManager.java:28)
Code (note that the exception comes from the super.doBegin()):
protected void doBegin(Object arg0, TransactionDefinition arg1) {
super.doBegin(arg0, arg1);
if (!Db2ClientInfo.exists()) {
clearDBProperty();
} else {
setDBProperty(Db2ClientInfo.getClientUserId(), Db2ClientInfo.getClientApplicationId());
}
}
private void setDBProperty(String uId, String appName) {
Session session = getSessionFactory().getCurrentSession();
Properties props = new Properties();
props.setProperty(WSConnection.CLIENT_ID, uId);
props.setProperty(WSConnection.CLIENT_APPLICATION_NAME, appName);
try {
Connection nativeConn = new SimpleNativeJdbcExtractor().getNativeConnection(session.connection());
if (nativeConn instanceof WSConnection) {
WSConnection wconn = (WSConnection) nativeConn;
wconn.setClientInformation(props);
} else {
logger.error("Connection was NOT an instance of WSConnection so client ID and app could not be set");
}
} catch (Exception e) {
throw new RuntimeException("Cannot set DB parameters!", e);
}
}
I just realized I never answered this. It turns out that the exception had nothing whatever to do with our Tx manager. It was the fact that this particular EAR has two apps in it, each pointing to the same data source. Evidently this confuses hibernate. We've plans to separate the apps some day, but creating an identical (except in name) data source and pointing the apps at them separately fixes the issue for now.
Instead of modifying the transaction manager it might be easier (better?) to create a wrapper around your datasource (extending DelegatingDataSource from spring) and override the 2 getConnection methods. For the cleanup you could wrap the connection in a proxy and intercept the close method.
That should be a safer (and easier I guess) way then trying to fiddle with the transaction manager and it works for every technology (JDBC, Hibernate, JPA etc.) as long as you use the wrapped datasource. (The registration could be done with a BeanPostProcessor which detects DataSource instances and simply wraps them in the delegate).
If that is to radical (as it means changing your current applications instead of updating a library). It could be a configuration problem, make sure that you are only loading your configuration (and thus DataSource and TransactionManager) only once, duplicating bean instances might lead to a similair behavior.
For posterity, I just got this problem and the answers here weren't very helpful. We resolved the problem by removing a double import of a core XML file which had the AOP transaction manager definition in it:
<tx:annotation-driven transaction-manager="..."
proxy-target-class="true" />
I'm thinking that it causes there to be 2 transaction managers overlapping the same namespace. To fix it, we moved the imports around so they were being done once.
Hope this helps someone else.

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