Hi Rebecca,
Hope you are doing good.
For the "1.JAVA Instance Task ABC shut down..." check the work folder files and the default traces.
For the "3.JAVA Heap Memory 97%> 80 % last value above threshold..." increase the heap memory values by atleast 1 GB if you have enough resources on the engine. On how to do this, see:
Configuring JVM Parameters - Administration - SAP Library
For this particular reason, SAP has developed the Quick Sizer (which is a Web-based tool).
This is available free of cost for customers from: <http://service.sap.com/quicksizer>
and
<http://service.sap.com/sizing>
You will be able to identify whether more hardware/ server nodes etc. are needed and resize the server accordingly. With the Quick Sizer you can translate business requirements into technical requirements. Simply fill in the online questionnaire, an up-to-date survey that is based on business-oriented figures. The results you obtain can help you select an economically balanced system that matches your company's business goals.
For 7.3 server in particular, do go through:
SDN Article: Performance Best Practices Guide for SAP NetWeaver Portal 7.3,
<http://scn.sap.com/docs/DOC-7284>
SDN Article: SAP NetWeaver Portal 7.3 - Tuning Caches,
<http://scn.sap.com/docs/DOC-7383>
Thank you!
_____________
Kind Regards,
Hemanth
SAP AGS