1) sounds good 2) why not do this checking every other time you access the object anyway? You could span a short lived thread (does just one check-up) for this. reason - daemon threads in app-sercvers (and servlet-engines) are not "loved" - you need something to watch over that daemon thread 3) poll only if the last value for a server is older than n seconds (saves some io)
else sounds good hth Alexander -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: Mittwoch, 26. Mai 2004 19:39 To: Struts Users Mailing List Subject: Re: scope and presenting realtime data (fwd) Dear All, Thanks for all your feedback. Based on the discussion i derive following conclusions. please comment on their accuracy. 1. A Data Storage object (Say a HaspMap with the server name as a key and the N value data object as value are stored along with the last updated time) -- we are not going for database to save time on I/O and do not want to deal with stale data in database. -- 2. A cleaner thread will wake-up periodically, and remove the server entry which is not being used for the last 'X' minutes -- This we need to do as we are having large number of servers to be monitored -- 3. For each request the bean class need to a. poll and get the current value b. get the stored data object for the server c. if the object exists, add the value and drop the oldest sample if size becomes N+1 d. if object does not exist, create with the current value e. update the value in data storage object thanks & regards -Ramudu On Wed, 26 May 2004, Irfandhy Franciscus wrote: > My advice may sound out of the context, > > but how bout actually storing each last N value to a database. this way > you can even have an archive of the Last N value. > > Or if you dont want to setup a database, just write the last N value to > a property file or text file. > > Regards, > Irfandhy Franciscus > > [EMAIL PROTECTED] wrote: > > Hi, > > > > Can anyone suggest some approach for this issue. > > > > thanks & regards > > -Ramudu > > > > > > ---------- Forwarded message ---------- > > Date: Wed, 26 May 2004 14:52:23 +0530 (IST) > > From: [EMAIL PROTECTED] > > Reply-To: Struts Users Mailing List <[EMAIL PROTECTED]> > > To: [EMAIL PROTECTED] > > Subject: scope and presenting realtime data > > > > Hi, > > > > We are developing a web based interface (struts + jsp etc) for realtime > > monitoring of server cpu usage. > > > > We have written a bean that will contact the server and get the current > > cpu usage and return that value. I want to plot a line graph (using > > jfreechart) with the cpu usage in Y-axis and time in X-axis. The Graph > > need to plot the last 'N' values + the current value during each refresh. > > > > The issue is how to remember these last N values. I do not want to assign > > session scope for this object as the end-user might monitor for more than > > one servers and several users might be using the system at same time. > > > > How this situation is typically handled in the Struts+jsp environment. > > > > thanks & regards > > -Ramudu > > > > > > --------------------------------------------------------------------- > > 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] > --------------------------------------------------------------------- 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]
