> > On Tuesday 13 November 2001 16:49, Dain Sundstrom wrote: > > > > > > The first time I reference let's say 10 Entity Beans after a > > > JBoss restart it > > > takes approx. 5 seconds to retrieve data from them. The > > > second and subsequent > > > requests to return data from the same 10 EBs take ~20ms. > > > > I was curious also, so I re-ran my test. The second run > always takes > > slightly less time ~1-2 sec. The only thing I can think of that is > > different in the first execution is the bytecode generator. > On my machine, > > a 1.4 athalon, it doesn't take anywhere 1/2 second per > bean. I really > > haven't been focusing on this type of optimization, but I > can easily add a > > line to the init or start method that creates an instance > of the bean. > > Then it will only happen during setup. I look at it after > the example code > > done (later today). > > > > JProbe is really a nice tool. > > It appears that most of the time is spent by my bean calling > Introspector.getBeanInfo(getClass()). I'm using introspection > to collect the > data from the EB. A single call to getBeanInfo() produces > around 500 calls > for ClassLoader.findClass() that in turn scan the filesystem > for class files. > Why is that so I don't know. Introspection is known to be > slow but I didn't > know that it can be of such a varying speed. getBeanInfo() on > a simple Object > subclass is quite fast. Not so on a JBoss generated subclass > (proxy) of an EB > class. > > The other thing that was shown is that getBeanInfo() is fast > the second time > called on a particular Class, so this overhead should only be > visible the > first time called for a particular Entity type, but it is > visible the first > time called for a particular Bean instance regardless of > Entity type. The > only conclusion is therefore that each Bean instance (even > though of the same > type) is of different Class despite your claims that it is not. > > The proof: This happens when accessing 3 instances of the > same type using > Introspector.getBeanInfo(getClass()) in the Bean's method: > > Obtaining BeanInfo for class: class > com.select.zaznamki.ejb.CustomerBean$Proxy, class.hashCode: 7674526, > classLoader: org.jboss.proxy.ProxyCompiler$Runtime@651e95, > classLoader.hashCode: 6626965 > Obtaining BeanInfo took 985 milliseconds. > > Obtaining BeanInfo for class: class > com.select.zaznamki.ejb.CustomerBean$Proxy, class.hashCode: 3724384, > classLoader: org.jboss.proxy.ProxyCompiler$Runtime@42fcc, > classLoader.hashCode: 274380 > Obtaining BeanInfo took 311 milliseconds. > > Obtaining BeanInfo for class: class > com.select.zaznamki.ejb.CustomerBean$Proxy, class.hashCode: 6004549, > classLoader: org.jboss.proxy.ProxyCompiler$Runtime@6c5356, > classLoader.hashCode: 7099222 > Obtaining BeanInfo took 305 milliseconds. > > > It appears that each instance of the Bean is created with a > different Class > instance using different instance of the ClassLoader. Is this > on purpose? > Wouldn't it be better to use the same Class?
You would think so. My use of the proxy generator is obviously broken. I'll look at it after some sleep. -dain _______________________________________________ Jboss-development mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/jboss-development
