I read about super pool in akka documentation. I am fairly new to Akka. Please help me understand how does superPool work in case I want to specify different connection pool settings for different hosts but send request to all using superpool. Would it take that configuration in consideration?
Related
We use a single mysql database for 2 applications. One of this application has 2 instances.
So we would like to know how cloudbees manage the connexion pool between all these apps. I saw in other threads that mysql default conf on cloudbees accept 20 connections. For the moment, we use "old" hibernate configuration with explicite c3p0 but we thought that they could try to open too much connexions on the db.
If we change the conf to use jndi cloudbees datasource (as describ here https://developer.cloudbees.com/bin/view/RUN/DatabaseGuide), should our apps share the same connection pool ? Or at least all instances of each app ?
Hope it's understandable. Let me know if not.
Thanks for your help,
Each instance of the app has its own connection pool - so you need to consider that in sizing the pool.
I have always followed the guidance of try/Close/catch/Abort when it comes to a WCF proxy. I am facing a code base now that creates proxies in MVC controllers and just lets them go out of scope. I'm arguing the case that we need to edit the code base to use try/Close/catch/Abort but there is resistance.
Does anyone know a metric (e.g. perfmon) I can capture to illustrate the problem/benefit. Or a definitive reference that spells out the problem/benefit no one can dispute?
You can create a sample application to mimic the problem. Though I haven't tried you can try this,
Create a simple service and limit the maxConcurrentCalls and maxConcurrentSessions to 5.
Create a client application and in that, call the service method without closing the connection.
Fire up 6 or more clients
See what happens when you open a new connection from a client. Probably the client will wait for certain time and you get some exception.
If the client don't close the connection properly, the connection will still remain open in the service so what happens if 1000s of client connected to the service at a time and leave their connections open? The service has a limitation that it could server 'n' connections at a time and because of that the service can't handle any new requests from clients and that's why closing connections are very important.
I think you are aware about the using problem in WCF service. In my applications I close the WCF connections using an extension method as said in this thread.
Have you tried a simple 'netstat -N' from the command prompt both on server and client? Yoy are likely to see a lot of waiting/pending connections which might exhaust your server resources for no reason.
I am working on a project which has following requirements:
Perform sticky based load balancing(based on SOAP session ID) onto multiple backend servers.
Possibility to plugin my own custom based load balancer.
Easy to write and deploy.
A central configuration file(Possibly an XML), to take care of all the backend servers.
Easy extraction of a node from this configuration file(Possibly with xpath).
I tried working with camel for a while but, wasn't able to do perform certain task with it.
So thought of giving a try to Akka.
Will akka be possibly able to satisfy the above requirements?
If so is there a load balancing example in akka or proxy example?
Would really appreciate some feedbacks.
You can do everything you've described with Akka.
You don't mention what language you're working with, Scala or Java. I've included links to the Scala documentation.
Before you do anything with Akka you HAVE TO read the documentation and understand how Akka works.
http://doc.akka.io/docs/akka/2.0.3/
Doing so, you'll find Akka is perfect for the project you've described with some minor caveats.
Once you read the documentation the following answers should make a lot of sense.
Perform sticky based load balancing(based on SOAP session ID) onto multiple backend servers.
Load balancing is already part of the framework (it's called Routing in Akka http://doc.akka.io/docs/akka/2.0.3/scala/routing.html) and Remoting (http://doc.akka.io/docs/akka/2.0.3/scala/remoting.html) will take care of the backend servers. You can easily combine the two.
To my knowledge the idea of sticky load balancing is not a part of Akka but I can envision this being accomplished with a Map using the session ID as the key and the Actor name (or path) as the value. A quick actorFor will take care of the rest. Not well thought out but should give you a good idea of where to start.
Possibility to plugin my own custom based load balancer.
Refer to the Routing documentation.
Easy to write and deploy.
This depends on your aptitude and effort but after you read certain parts of the documentation you should be build a proof of concept in a couple of hours.
Deployment can be a bit frustrating mostly because the documentation isn't really great with respect to deploying Akka networks with remote components. However, there are enough examples on the web that you can figure out how to get it done...eventually. Once you do it once it's no big deal.
A central configuration file(Possibly an XML), to take care of all the backend servers.
Akka uses Typesafe Config (https://github.com/typesafehub/config) which is a lot easier to work with than XML (but I hate XML so take that with a grain of salt). As far as a central configuration, I'm not sure what you're trying to accomplish but it sounds like something that can be solved using remote actor creation. Again, see the Remoting documentation.
Easy extraction of a node from this configuration file(Possibly with xpath).
Akka provides a lookup method .actorFor. There's no need to go to the configuration file once the system is up and running.
If so is there a load balancing example in akka or proxy example?
Google is your friend.
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
I would like a recommendation/idea on a method to configure properties for a running Mule service dynamically, i.e. I want the service to pick up the new settings without the need to restart Mule. Typically the kind of properties/settings I would like to change are FTP connector user ID, passwords, service URLs etc.
Any idea would be welcome.
Regards, Ola
Use the URI endpoint format do dynamically address endpoints. In simple cases you may be able to use the message properties in a TemplateEndpointRouter
Otherwise You need to write a component that composes the URI and sends the message to the dynamic endpoint using the MuleEventContext or MuleClient.
See here:
http://www.mulesoft.org/documentation/display/MULE2USER/Outbound+Routers#OutboundRouters-TemplateEndpointRouter
http://www.mulesoft.org/documentation/display/MULE2USER/Using+the+Mule+Client#UsingtheMuleClient-PerforminganEventRequestCall
http://www.mulesoft.org/documentation/display/MULE2USER/Mule+Endpoint+URIs
Mule exposes all service configuration via JMX, but I don't see any obvious way to reconfigure the connectors without a restart. They are internally managing pools of connections.
If there is a limited, you can create connectors for each and reconfigure the routes via jmx attributes.
If it is to be fully dynamic you likely need to implement your own service component to manage the ftp connection. Exposing the connection management, configuration, and restarting via JMX should be pretty straight forward.