How to handle Humantask without Minaserver in JBPM 5 - apache

I'm using apache mina server to process my workflow.
But when too many processes are launched the Mina server is occupying much of JVM and i couldnt progress further.
One instance of "org.apache.mina.transport.socket.nio.NioSocketSession" loaded by
"org.jboss.classloader.spi.base.BaseClassLoader # 0xb9b10d58" occupies 685,361,840 (68.96%) bytes.
The memory is accumulated in one instance of "java.lang.Object[]" loaded by "<system class loader>".
1.So is there any other alternative to Mina..?
2.How to handle my human task without Mina..?
Kindly suggest a solution...

There are two alternatives to Apache Mina currently supported in jBPM 5.2
- LocalTaskService: runs locally, next to your process engine
- HornetQ: uses HornetQ messages for communication between client and server
Kris

Related

Behavior of WL.server.createEventSource on a Worklight Cluster Environment

Let's assume I have a cluster of 2 worklight servers sharing the same WL runtime.
On that runtime, I've installed a application with a adapter that is a create event source function.
Just like this IBM article.
https://www.ibm.com/developerworks/community/blogs/worklight/entry/configuring_a_polling_event_source_to_send_push_notifications?lang=en
My question is, what will happen on a cluster environment.
Will repeated work ensue?
By other words, would my two WL Servers will be pooling for events?
Or perhaps that functionality is writing a task on the WL DB that the WL Servers poll regularly to check for work if no instance is taking care of it, so that only a server at a time would be "the event source"?
I'm working with IBM Worklight 6.2 and Websphere Liberty Profile 8.5.5
Thanks in advance!
Here's my attempt to answer this after some consultation:
My question is, what will happen on a cluster environment. Will
repeated work ensue? By other words, would my two WL Servers will be
pooling for events?
While the Worklight Servers share the same runtime, they are still considered as 2 instances. This means that each of them will attempt to perform a polling action. This is considered OK.
However, it is important to note that the backend system that is being polled should likely be smart enough to handle such a situation where 2 polling attempts are done for the same message.
If the backend doesn't know how to handle polling properly, the same message can be pulled more than once. This is true even of you have a single eventsource running. So this is something to keep in mind.

Jconsole randomly stops connecting

We have a jboss 7 instance running and hosting a web application. JMX remote has been turned on with username/password authentication and we are able to connect to it fine. Kindly not we are using Jboss/bin/jconsole.bat to connect.
However at times we notice after the following 2 cases it stops allowing any more connections to jmx unless we restart the jboss server. the cases are
1) we attempt a heap dump of the JVM using jconsole
2) We invoke a softreset method on a c3p0 datasource object that has been exposed via spring JMX
Not necessarily after doing any of the 2 it will always stop working. At times it stops taking new connections after trying one heap dump or at times after 3-4 successful attempts.
Any clue on this random behaviour of jconsole?
I think you ware bit by connection leak bug that AS 7.1.x had and it is fixed with 7.2.x versions.
I would recommend you to take EAP 6.1.0.Alpha1 (same as 7.2.0.Final) and try again.
If I recall correctly this was the original issue https://issues.jboss.org/browse/REMJMX-45

Cluster-wide singleton in Websphere Cluster

I need to run a component using Apache Camel (or Spring Integration) under WAS ND 8.0 cluster. They both run some threads on startup, and stop them on shutdown normally. No problem to supply WAS managed threadpool. But that threads must run on single cluster's node at the same time. Moreover it must be high-available i.e. switch to other node when active node falls.
Solution I found - is WAS Partitioning Facility. It requires additional Extended Deployment licenses. Is it the only way, or there is some way to implement this using Network Deployment license only?
Thanks in advance.
I think that there is not a feature that address this interesting requirement.
I can imagine a "trick":
A Timer EJB send a message on a queue (let's say 1 per minute)
Configure a Service Integration Bus (SIB) with High Availability and No Scalability, so the HA Manager ensure that only one messaging engine (ME) is alive.
Create a non-reliable queue for high performances and low resource consumption.
The Activation Spec should be configured to listen only local ME.
A MDB implement the following logic: when the message arrives, it check if the singleton thread is alive, otherwise it start the thread.
Does it make sense?

Understanding Apache ActiveMQ

I am confused about the function of Apache ActiveMQ.
I downloaded ActiveMQ from this link.
So I use it this way (environment: Windows 7): I start the bin/activemq.bat, then it works.
My question is: Does this mean I start a server on my machine? When I initialize the ActiveMQConnectionFactory, the broker URL is tcp://localhost:61616. But what if I want my machine to serve as a server and another machine to connect to my server?
Yes, you can use the primary box as a server and have consumers/subscribers running on other boxes (which will need to connect to the server - you will need to specify the server hostname & port for the connection to be established) - once in place, the messages on the server (topic or queue) can be consumed by the clients.
If you one have one producer and one consumer, you can look into using queues - if you have more than one consumer/subscriber, you can look into setting up a topic to which the consumers will subscribe to. Messages need to be inserted to the topic/queue as needed.
You can specify the server information in your code or preferably in the config file.
For reference to topologies:
http://activemq.apache.org/topologies.html
Also, you can choose to persist your messages or not based on your use case. Kaha DB is the preferred route (specially if performance is of concern).
Useful examples:
http://sujitpal.blogspot.com/2007/12/jms-patterns-with-activemq.html
http://vvratha.blogspot.com/2012/05/java-client-to-sendreceive-messages-for.html
Hope it helps.
Apache ActiveMQ ™ is the most popular and powerful open source messaging and Integration Patterns server
& it act like a third party server.
Apache ActiveMQ is fast, supports many Cross Language Clients and Protocols, comes with easy to use Enterprise Integration Patterns and many advanced features while fully supporting JMS 1.1 and J2EE 1.4. Apache ActiveMQ is released under the Apache 2.0 License.
ActiveMQ have the capabilities to send 100 MB single message framework and maintain 1000 concurrent connection simultaneously , for the further information you can check activemq.xml in your documentation.
Further Info at here about the ActiveMQ

IIS, APACHE, YAWS runtime environment

Recently I gone through a an article explaining potentiality of YAWS server and the number of requests it processes per second. It was mentioned that YAWS can handle 80K requests per second and it also run in multi threaded environment to improve request processing limit.
How can we compare IIS, Apache with YAWS? Which one will process maximum requests? Can I find any comparisons somewhere?
Check this link out:http://www.sics.se/~joe/apachevsyaws.html Link to Yaws vs apache
You see that Yaws handles 80000 concurrent requests (and continuing) while apache fails at around 4000 connections. This is because Yaws runs on the Erlang/OTP VM. Processes belong to this machine and not the operating system. Erlang has been highly customised for concurrent programming. Infact, other erlang web applications like:mochiweb,webmachine, e.t.c are much more powerful than apache when it comes to handling many concurrent requests. Yaws web server scales better than any web server i know of today. With the ability to create appmods, you can create Erlang Applications that communicate over http protocol, making use of the power of yaws.
Yaws home page is: http://yaws.hyber.org/. Actually, Yaws gets its power from OTP (Open Telecom Platform). This set of powerful libraries found at http://erlang.org/, has the most advanced design patterns such as fail over systems, supervision trees, finite state machines, event handlers, e.t.c, You should actually start using erlang for your next web application!!!!