Interested to Buy Any Domain ? << Click Here >> for more details...
can anyone tellme java instance startup sequence?
- 1 Answers
- 9746 Views
- Cap Gemini, Wipro, I also Faced
- E-Mail Answers
Answer Posted / pavan
Process
Startup of the Java Instance
The following steps are involved in starting the Java instance:
JSTART is started (in Windows by the SAP Start Service; on UNIX platforms by the startsap script). It takes the role of the Java instance controller.
The Java instance controller analyzes its configuration (from the instance profile) and examines the details of the Java SDK defined there.
The Java instance controller initializes SAP signal handling to be able to receive signals and opens the control port.
The Java instance controller reads the instance description (from the list of files specified by the jstart/startupNodeFiles and jstart/instanceNodeFiles profile parameters) for the first time, searching for nodes with a runLevel=1 property. The OFFLINE DEPLOYMENT node in the startup.properties file matches this criterion.
The Java instance controller starts another JSTART process with the parameters from the OFFLINE DEPLOYMENT node and waits for the child process to terminate.
The child process acts as a Java process. It loads the Java Virtual Machine (JVM) into its own process, initializes the JVM and starts the OFFLINE DEPLOYMENT program, which performs the deployment steps in the Java database.
The Java instance controller reads the instance description again, searching for nodes with a runLevel=2 property. The BOOTSTRAP node in the startup.properties file meets this condition.
The Java instance controller starts another JSTART process with the parameters from the BOOTSTRAP node and waits for the child process to terminate.
The child process loads and initializes the JVM and starts the BOOTSTRAP program. BOOTSTRAP synchronizes the binary data in the Java database with the local file system, reads the Java instance description from the Java database and updates the instance.properties file.
The Java instance controller reads the instance description from the startup.properties and instance.properties files once more, this time focusing on nodes with a runLevel=3 property or without a runLevel property at all. These nodes form the productive instance.
The Java instance controller starts the processes for infrastructure nodes, such as ICM or DEBUGPROXY.
When all infrastructure processes are started, the Java instance controller starts the processes for the server nodes.
The JSTART child processes act as Java processes and execute a similar sequence as described before. They become the Java server processes.
The following figure shows the sequence of actions that the Java Startup Framework executes.
This graphic is explained in the accompanying text.
Operation of the Java Instance
The Java instance controller monitors the Java instance. It receives the status update messages and catches termination signals from the child processes. When a process terminates unexpectedly, the Java instance controller starts the process again.
Shutdown of the Java Instance
Signals and commands sent to the control port trigger a Java instance to stop. The Java instance controller ensures that the order of shutdown is obeyed and forces termination if a process does not stop within the shutdown timeout period.
The figure below shows the sequence of the actions.
This graphic is explained in the accompanying text.
An instance is stopped as follows:
A process (for example, the ABAP dispatcher, a start script or SAP Start Service) sends a SIGINT signal or an appropriate command to the Java instance controller.
The Java instance controller updates the instance state and sends STOP commands to the server processes.
When the server processes are finished, the Java instance controller sends STOP commands to the infrastructure processes.
Once all child processes have exited, the Java instance controller terminates.
| Is This Answer Correct ? | 6 Yes | 1 No |
Post New Answer View All Answers
How you will do that?
Error in the phase import_proper while applying support packages?
What is the importance of table t000?
if i want to limit the condition record validity for forst 10 orders how can i do tht plz ans i hve interview in 2/3 days
What is MySAP?
What is the difference between Party & Service without party in XI (ID)?
In a situation where my sap system is down (users unable to login to sap system), how to analyze the problem?
What is the purpose of webdisptcher and Installing and configuring Web Dispatcher what are the prerequisites?
What is luw (logical unit of work)?
when ever i try to installed sap ecc6.0 sr2 on single system. it show error on phase import abap "Not all objects are successfully processed. DIAGNOSIS: for details see output file with invalid object invalid_objects.txt and log file object_checker.log . SOLUTION: normally it indicate the data load error but in some special cases( for example if some object were created or loaded externally) you can press ok to continue" here error sentence is complete. pls tell what actual error its? is it kernel file related?
Can you tell me installation procedure of SAP on UNIX
If possible send me screenshot doc for installation of ecc6
What is a background processing batch scheduler?
How to make security authorization reports?
What is the difference between kernel replacement and support package?
