Could someone explain to me what SAP instance is? Is it also installed on the SAP application server?
The role of a SAP instance is to deliver SAP Processes (DIA, BGD, UPD, ...).
A SAP System (SID) can be made of 1 CI (Central Instance) and 1,n DIALOG instances.
You can get the list of SAP Instances using of your SAP System using
SM66 t-code.
CI (Central Instance) hosts Enqueue and Message server.
The term instance is used in SAP when you have a lot of clients.
If you see ADM100 pdf manual, they specify an instance as a group of multiple clients(more than 50...).
Don't confuse an instance with developing a program, they are two different things.
Call it server,call it client,you can install SAP on a machine.
Machine,Server, Client, they are the same, but are used in different contest.
Also you could have a single machine with a lot of instance virtualized, where in every virtual system is installed sap, then you could say that this machine holds an instance.
Be careful Dirk,On a sap system you can have Abap based sap systems or Abap+Java based sap system, I would be careful to use the word instance.
Sanaz,
In addition to the responses of Dirk, Admin2017 and Fedoco, I can advise SM51 t-code.
AS (Application Server) Instances of SAP Server.
You can find in this transaction information about:
Application Server Instance (or Instances),
Host (server address)
Instance Services (List of instance services)
State (eg:Active)
In SAP environments, an Instance usually means a SAP Netweaver instance. Netweaver is the server software that runs SAP applications like ERP, CRM, PI and others, both Java and ABAP. You can have several instances configured on a single server - they share a few common directories, other directories are instance specific. A Netweaver application server would be one instance running on your server.
Related
My management is evaluating non-Azure Microsoft Windows Service Bus (Azure is out of consideration for security reasons). It will be used to setup topic/subscription model with a number of WCF services with netMessagingBinding that we building, so I just have a few basic questions about that.
Are there any specific hardware requirements like dedicated server, dedicated database etc. for WSB to run in production environment?
It's easy to configure WCF service to listen on a specific topic subscription. Is there any way for WCF service to listen to multiple subscriptions?
Appreciate the answers.
You can install the service components and the databases all on one server (that is the default). However, for a number of reasons, we installed the services on a dedicated app server and then created the Service bus databases on an existing database server. The install package allows you to specify a different db server. Check this article for the minimum server requirements
Yes you can get one WCF service to listen to multiple subscriptions. You would need to create two (or more) System.ServiceModel.ServiceHost instances and then run them inside one process. For example we had one windows service running two ServiceHost's. Each host listened at a different queue and therefore implemented a different contract. This meant where queues were logically grouped we didn't need a new windows service per queue. You could do the same with subscriptions.
For question one, you will have to go through the exercise of hardware sizing. the good news is that WCF services can scale vertically, so you can add up servers if there were issues in handling client load.
To do hardware sizing you will have to make an estimate the expected load and then do performance/scalablity testing to figure the load bearing capacity of your serviceBus/services .
you could find a lot of resources for load testing like this one http://seroter.wordpress.com/2011/10/27/testing-out-the-new-appfabric-service-bus-relay-load-balancing/
once you do load testing and come up with the numbers, you can then do sizing using references like this one http://msdn.microsoft.com/en-us/library/bb310550.aspx
This is more of a high level question. But say you have a large number of applications, many of them distributed (server/clusters) and they share configuration parameter.
What is a good way to store this application specific configuration (preferable in a central place) without relying on a single point of failure.
For configuration I mean things like "database server addresses", "web services endpoint", "Logging file name" and even why not some business related constants and parameter.
Some of this parameter could eventually be changed at runtime so the application needs to be able to also query dynamically these parameters.
I can think of an application storing the configuration at a local file (forget about the format) or a central database to store the same.
But I would like to ask the community if there are standards for handling configuration of multiple distributed systems.
Thanks.
Apache ZooKeeper is a centralized service for maintaining configuration information, naming, providing distributed synchronization, and providing group services.
I can imagine that the 'server' can be a machine/host but can be also a program like ftp server, smtp server, etc..
The 'service' on the other hand refers mainly to applications/programms..
Why can then for example the Sql Server cannot be called as Sql Service? It has the same semanthics. Or the other way round: MS Azure service: why it isn't called Azure Server? :)
I would say:
A server is expected to give a response
A service is not
Additionally, a service may include more than a server - it may well be an environment, hardware, SLA and more.
The services are features offered by the servers.
A server is a (possibly virtualized) piece of equipment that can be used to provide a service.
A service is something that you can use (usually remotely) that is provided by one or more servers.
The other difference is that these are really concepts at different levels of abstraction. Servers are concrete things. Services are abstract. Yet people mostly use services, and don't really care about what servers are used to implement them. Do you care about what servers are used to provide Google's web search service? No, you don't. Do you care about what servers are used to provide Amazon's cloud service? No, you don't.
A server is a a software program, or the computer on which that program runs, that provides a specific kind of service to client software running on the same computer or other computers on a network.
Per Microsoft - Windows Azure: operating system as an online service.
SQL Server is a Server, Any Stored Procedures or functions you write are Services. (A Query is a dynamic Service that has a life of just the call, it is sent to the Database, compiled, The Server executes the compiled code and returns the results)
I would say that there's no difference. They're used more-or-less interchangeably.
Or, if you prefer: you can come up with a definition, and someone will come up with a counter-example.
I have a WebLogic cluster on which I've deployed numerous topics and applications that use them. My applications uniformly show themselves in a Warning status. Looking at Monitoring on the deployment, I see the MDB application connects to Server #1, but on server #2 it shows this:
MDB application appName is NOT connected to messaging system.
My JMS Server is targetted to a migratable target, which is in turn targetted to the #1 server and has a cluster identified. And messages sent to either server all flow as expected. I just don't know why these deployments show in a Warning state.
WebLogic 11g
This can be avoided by using the parameter below
<start-mdbs-with-application>false</start-mdbs-with-application>
In the weblogic-application.xml, Setting start-mdbs-with-application to false forces MDBs to defer starting until after the server instance opens its listen port, near the end of the server boot up process.
If you want to perform startup tasks after JMS and JDBC services are available, but before applications and modules have been activated, you can select the Run Before Application Deployments option in the Administration Console (or set the StartupClassMBean’s LoadBeforeAppActivation attribute to “true”).
If you want to perform startup tasks before JMS and JDBC services are available, you can select the Run Before Application Activations option in the Administration Console (or set the StartupClassMBean’s LoadBeforeAppDeployments attribute to “true”).
Refer :http://docs.oracle.com/cd/E13222_01/wls/docs81/ejb/message_beans.html
this is applicable for the versions till 12c and later
I don't like unanswered questions, so I'm going to answer this one.
The problem is resolved, though I was not involved in its resolution. At present the problem only exists for the length of time it takes the JMS subsystem to fully initialize. During that period (with many queues, it can take a while) the JNDI system throws errors and the apps are truly in warning state. Once the JMS is fully initialized, everything goes green.
My belief is that someone corrected something in the JMS Server / Cluster config. I'll never know what it was.
We are working on developing a Java EE based application. Our application is Java 1.5 compatible and will be deployed to WAS ND 6.1.0.21 with EBJ 3.0 and Web Services feature packs. The configuration is currently one cell with two clusters. Each cluster will have two nodes.
Our application, or our system, as I should rather say, comes in two or three parts.
Part 1: An ear deployed to one cluster that contains 3rd party vendor code combined with customization code. Their code is EJB 2.0 compliant and has a lot of Remote Home interfaces.
Part 2: An ear deployed to the same cluster as the first ear. This ear contains EBJ 3's that make calls into the EJB 2's supplied by the vendor and the custom code. These EJB 3's are used by the JSF UI also packaged with the EAR, and some of them are also exposed as web services (JAX-WS 2.0 with SOAP 1.2 compliance) for other clients.
Part 3: There may be other services that do not depend on our vendor/custom code app. These services will be EJB 3.0's and web services that are deployed to the other cluster.
Per a recommendation from some IBM staff on site here, communication between nodes in a cluster can be EJB RMI. But if we are going across clusters and/or other cells, then the communication should be web services.
That said, some of us are wondering about performance and optimizing communication for speed of our applications that will use our web services and EJB's. Right now most EJB's are exposed as remote. (and our vendor set theirs up that way, rather than also exposing local home interfaces). We are wondering if WAS does any optimizations between apps in the same node/cluster node space. If two apps are installed in the same area and they call each other via remote home interface, is WAS smart enough to make it a local home interface call?
Are their other optimization techniques? Should we consider them? Should we not? What are the costs/benefits? Here is the question from one of our team members as sent in their email:
The question is: Supposing we develop our EJBs as remote EJBs, where our UI controller code is talking to our EXT java services via EJB3...what are our options for performance optimization when both the EJB server and client are running in the same container?
As one point of reference, google has given me some oooooold websphere performance tuning documentation from 2000 that explains a tuning configuration you can set to enable Call By Reference for EJB communication when they're in the same application server JVM. It states the following:
Because EJBs are inherently location independent, they use a remote programming
model. Method parameters and return values are serialized over RMI-IIOP and returned
by value. This is the intrinsic RMI "Call By Value" model.
WebSphere provides the "No Local Copies" performance optimization for running EJBs
and clients (typically servlets) in the same application server JVM. The "No Local
Copies" option uses "Call By Reference" and does not create local proxies for called
objects when both the client and the remote object are in the same process. Depending
on your workload, this can result in a significant overhead savings.
Configure "No Local Copies" by adding the following two command line parameters to
the application server JVM:
* -Djavax.rmi.CORBA.UtilClass=com.ibm.CORBA.iiop.Util
* -Dcom.ibm.CORBA.iiop.noLocalCopies=true
CAUTION: The "No Local Copies" configuration option improves performance by
changing "Call By Value" to "Call By Reference" for clients and EJBs in the same JVM.
One side effect of this is that the Java object derived (non-primitive) method parameters
can actually be changed by the called enterprise bean. Consider Figure 16a:
Also, we will also be using Process Server 6.2 and WESB 6.2 as well in the future. Any ideas? recommendations?
Thanks
The only automatic optimization that can really be done for remote EJBs is if they are colocated (accessed from within the same JVM). In that case, the ORB will short-circuit some of the work that would otherwise be required if the request needed to go across the wire. There will still be some necessary ORB overhead including object serialization (unless you turn on noLocalCopies, with all the caveats it brings).
Alternatively, if you know that the UI controller is colocated, your method calls do not rely on parameter or return value copying, and your interface does not rely on the exception differences between local and remote views, then you could create and expose a local subinterface that will be much faster than remote access through the ORB.