The point is well-taken and reinforces the observation that performance analysis is subtle and situation-specific.
----- Original Message ----- From: "Mike Bresnahan" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Cc: <[EMAIL PROTECTED]>; "Fred Loney" <[EMAIL PROTECTED]> Sent: Sunday, April 07, 2002 2:15 PM Subject: RE: SSB vs. Singleton > Well stated, Fred. I want to make one extra point about the case where a > database call is involved. Even if a single call is only .001 times faster, > I do not feel that the performance difference is always negligible if you > are developing a multi-user system. All extra CPU cycles used to make the > EJB call rather than a local call are CPU cycles that cannot be used for > something else. For example, the CPU cycles cannot be used by another > application sharing the CPU, a database server sharing the same CPU, or > another thread within the same application sharing the same CPU. So while > the response time of the specific call may not be noticeably effected, the > total throughput of the system may be noticeably effected. > > Mike Bresnahan > > P.S. I am CCing you because I have yet to see one of my posts make it > through the list. Should I be seeing my own posts? Do you get bombarded > with out-of-office emails after a post? > > > -----Original Message----- > > From: A mailing list for Enterprise JavaBeans development > > [mailto:[EMAIL PROTECTED]]On Behalf Of Fred Loney > > Sent: Sunday, April 07, 2002 3:49 PM > > To: [EMAIL PROTECTED] > > Subject: Re: SSB vs. Singleton > > > > > > There was a related thread on this last week; cf. > > http://swjscmail1.java.sun.com/cgi-bin/wa?A2=ind0204&L=ejb-interest&D=0&; > > P=1833 and ensuing discussion. > > > > Regarding speed, it is important to consider the execution context. > > Presumably the example in the message cited below is a simple in-memory > > operation. On the other hand, if the SSB call hits the database, as is > > often the case, then the time is dominated by IO rather than the method > > call differential. So, to extend the example, if the actual duration of > > the call under load is as follows: > > > > 1.0000001 sec with a Java class > > > > 1.001 sec with a SSB > > > > then using the Java class is less than .001 times faster than a SSB, not > > 10,000 times faster. There is no pat rule for which is better, but in an > > EJB project it is preferable to look at code integrity and quality of > > service first, since it is usually easier to analyze than performance. > > > > Fred Loney > > Spirited Software, Inc. > > www.spiritedsw.com > =========================================================================== To unsubscribe, send email to [EMAIL PROTECTED] and include in the body of the message "signoff EJB-INTEREST". For general help, send email to [EMAIL PROTECTED] and include in the body of the message "help".
