I've wanted a nickname all my life (aside from the explicitives some would use!)... never thought it's be Radar :)
-- Frank W. Zammetti Founder and Chief Software Architect Omnytex Technologies http://www.omnytex.com On Fri, March 18, 2005 1:09 pm, Dakota Jack said: > The class works, but I don't think it is what you want. Maybe it is. > Just don't have high expectations. I did and was disappointed. Just > trying to help you out, Radar! ///;-) > > Jack > > > On Fri, 18 Mar 2005 12:21:28 -0500 (EST), Frank W. Zammetti > <[EMAIL PROTECTED]> wrote: >> Why do you think it wouldn't work? Does it sometimes return incorrect >> information in some setups? >> >> I thought of doing some kind of mini-browser-type thing, but before I go >> down that road I wanted to explore some simpler solutions. The Commons >> ID >> thing is very nice, but I'm not so sure I'm comfortable putting in >> something that isn't actually released yet. >> >> That being said, what was on the site for it got me to thinking... I >> think >> if I do a combination of the sum of the MAC address digits + the current >> time + the hashCode of the IP address, that is probably as random as I >> need. But, if you know something about InetAddress that would make this >> not work, I'm all ears :) >> >> Of course, I'm not sure how to get the MAC address yet, but one problem >> at >> a time... >> >> -- >> Frank W. Zammetti >> Founder and Chief Software Architect >> Omnytex Technologies >> http://www.omnytex.com >> >> On Fri, March 18, 2005 12:14 pm, Dakota Jack said: >> > InetAddress might not get the answer for you, Frank. I don't know >> > what your setup is, but you can go to any ip address service outside >> > your system and get a unique return address for your machines with a >> > mini-browser. >> > >> > Jack >> > >> > >> > On Fri, 18 Mar 2005 11:36:10 -0500 (EST), Frank W. Zammetti >> > <[EMAIL PROTECTED]> wrote: >> >> Yes, I think InetAddress just might do the trick. Thank you Kris! >> >> >> >> -- >> >> Frank W. Zammetti >> >> Founder and Chief Software Architect >> >> Omnytex Technologies >> >> http://www.omnytex.com >> >> >> >> On Fri, March 18, 2005 11:24 am, Kris Schneider said: >> >> > Will InetAddress.getLocalHost() work for you? >> >> > NetworkInterface.getNetworkInterfaces() might also be of interest. >> Or, >> >> you >> >> > might want to create yourself an instance of java.rmi.dgc.VMID... >> >> > >> >> > Quoting "Frank W. Zammetti" <[EMAIL PROTECTED]>: >> >> > >> >> >> Oh boy, I got a good one! It's only related to Struts in that the >> >> >> application in question is Struts-based, so I hope no one minds a >> >> >> semi-OT >> >> >> question... >> >> >> >> >> >> Here's the situation... An app I wrote has a daemon thread that is >> >> >> spawned >> >> >> at startup (from a Struts plugin) that does periodic background >> >> >> processing >> >> >> tasks. This works great, never had a bit of trouble. >> >> >> >> >> >> Now though, the app is moving from a single server to a clusted >> >> >> environment. >> >> >> >> >> >> So, what's going to happen is that each server in the cluster will >> >> have >> >> >> its own instance of the thread running on it. Not a huge problem >> >> except >> >> >> that I have to be sure only one instance of the thread (i.e., one >> >> server >> >> >> in the cluster) is executing concurrently. >> >> >> >> >> >> The easy solution is just a database table that is checked when >> the >> >> >> thread >> >> >> wakes up. If there is no entry in it, then there is no other >> >> instance >> >> >> running, so it can write an entry to the table and go off and do >> its >> >> >> thing. >> >> >> >> >> >> I want to be extremely certain that no issues arise in terms of >> one >> >> >> instance of the thread reading from the database while another >> >> instance >> >> >> is >> >> >> writing, etc. So, aside from transactional database calls and >> >> row-level >> >> >> locking, I want to do one more thing: I want the thread to sleep a >> >> >> random >> >> >> number of seconds (1-300) at startup. This will ensure that, all >> the >> >> >> database locking and such aside, the threads should all be offset >> >> from >> >> >> one >> >> >> another in terms of when they run. >> >> >> >> >> >> So, I need a random number generated when the thread starts up. >> As >> >> we >> >> >> all >> >> >> know though, random number generation on most computers that don't >> >> have >> >> >> something like a Brownian motion sensor attached stuck in a cup of >> >> >> boiling >> >> >> coffee can't generate truly random numbers. So, in theory, what >> >> could >> >> >> happen is that if all the servers in the cluster come up at the >> same >> >> >> time, >> >> >> the threads could wind up running at the same time regardless of >> the >> >> >> random sleep at the start! It might never happen in reality, >> small >> >> >> fluctuations would probably offset them anyway, but I want to be >> more >> >> >> certain than that. >> >> >> >> >> >> So now we're at the crux of the problem... >> >> >> >> >> >> I can't just seed the random number generator with the current >> time >> >> >> because it concievably might not be random enough. So, I thought >> I >> >> >> could >> >> >> just tally up the octets of the server's IP address and add that >> to >> >> the >> >> >> current time. Then the seed on each server should be different >> >> enough. >> >> >> >> >> >> But, there doesn't appear to be any way to get the server IP >> address >> >> >> independant of a request, so I can't get at it in my plugin. >> Anyone >> >> >> know >> >> >> differently? >> >> >> >> >> >> Assuming that is the case, can anyone think of any other way to >> seed >> >> the >> >> >> generator that would ensure a different value on different >> machines >> >> in >> >> >> the >> >> >> cluster? There are some options like encoding the individual >> server >> >> >> names >> >> >> in my app's config file with a different seed value for each, but >> >> that >> >> >> makes maintenance a pain if a new server is added or one removed >> or >> >> >> addresses simply changed. >> >> >> >> >> >> Any ideas? Thanks! >> >> >> >> >> >> -- >> >> >> Frank W. Zammetti >> >> >> Founder and Chief Software Architect >> >> >> Omnytex Technologies >> >> >> http://www.omnytex.com >> >> > >> >> > -- >> >> > Kris Schneider <mailto:[EMAIL PROTECTED]> >> >> > D.O.Tech <http://www.dotech.com/> >> >> > >> >> > --------------------------------------------------------------------- >> >> > To unsubscribe, e-mail: [EMAIL PROTECTED] >> >> > For additional commands, e-mail: [EMAIL PROTECTED] >> >> > >> >> > >> >> >> >> --------------------------------------------------------------------- >> >> To unsubscribe, e-mail: [EMAIL PROTECTED] >> >> For additional commands, e-mail: [EMAIL PROTECTED] >> >> >> >> >> > >> > >> > -- >> > "You can lead a horse to water but you cannot make it float on its >> back." >> > ~Dakota Jack~ >> > >> > --------------------------------------------------------------------- >> > To unsubscribe, e-mail: [EMAIL PROTECTED] >> > For additional commands, e-mail: [EMAIL PROTECTED] >> > >> > >> >> > > > -- > "You can lead a horse to water but you cannot make it float on its back." > ~Dakota Jack~ > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > > --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
