Our subject is a J2EE ERP Program System
(from Purchase, Raw Mat., Prod., Order
Management until Delivery & Invoicing,
to A/P, A/R, G/L, Cost Acctg), using
JBOSS/Apache/Tomcat, Oracle 8i, and Linux,
with 5,000 Session Beans and Entity Beans.
We use 1 Dual Xeon-Processor Server with 8 GB
RAM for the Oracle 8i DB, and 1 Dual Xeon-
Processor with 8 GB RAM for Application Server
Problem = unpredictable Response Times:
a) Generally the first 2-3 hours after restart
are okay with around 3 seconds response time
b) After a few hours the response time increases
to up to 60 seconds, and finally everything hangs
c) Occasionally the same program with 2-3 seconds
response time suddenly needs 60 seconds response
time, also during the first hour after restart
Questions:
a) Max. Heap Size = 1.024 GB only? (Solaris = 8 GB?)
b) Garbage Collector works only upon restart?
c) Do we choke the DB-connection because we use
3 ways to access the DB?:
1) To READ-WRITE = Entity Beans
2) To READ ONLY:
a) some Session Beans use direct JBOSS-Connection
b) directly from EJB, not using JBOSS-Connection?
