Hi Castor gurus, I am new to castor and am trying to use it on a fairly large project. I am concerned about the overhead of jdo.getDatabase(). To me it appears that when you request for a database it loads up the mapping. Which I think is a heavy job, specially when the mapping gets large. In my case it will get large. Please tell me it isn't so.
regards, Dinesh At Friday, 31 January 2003, you wrote: >try searching the mailing list for: "best practices and samples for servlet >environment/application server (jboss) environment". > >basically, each call to the db, a servlet call would need to obtain a new >db connection via jdo.getDatabase(). [sharing connections wouldn't work, >since it is possible that a db operation by a single servlet request might >need to rollback the operations attempted on the connection.] although >getting a new connection for each servlet request seems like a lot of >overhead, using the container's jndi lookup should improve performance, as >many containers or jdbc drivers (from what i've read) provide connection >pooling. also castor does have a cache, so if an object is in the cache, >it won't call the db, depending on the castor cache-type setting. > >i'm still learning castor myself, so hopefully the castor veterans will >also share their insights. > >At 10:14 03/01/31 -0500, you wrote: >>Hiya, >> >>I hadn't considered thread-safety, so I'm very glad this came up. Are you >>(collectively) saying that there is a potential problem with the following >>scenario? >> >>- multiple users in a servlet application >>- each referencing their own xml document (no concurrent access to the same >>document) >>- each frequently reading from and writing to their document in a native XML >>DB >>- The Castor value objects for each client stored in HttpSession >> >>If so, then you're saying we need to throttle the servlet to one operation >>at a time? >> >>(Please tell me that isn't so) >> >> > -----Original Message----- >> > From: Conor Allen [SMTP:[EMAIL PROTECTED]] >> > Sent: Friday, January 31, 2003 9:55 AM >> > To: [EMAIL PROTECTED] >> > Subject: Re: [castor-dev] Using Castor safely in Servlets >> > >> > You can synchronize on the servlet itself or make the servlet single >> > threaded. >> > >> > Conor >> > >> > -----Original Message----- >> > From: Robert Kent [mailto:[EMAIL PROTECTED]] >> > Sent: 31 January 2003 14:17 >> > To: [EMAIL PROTECTED] >> > Subject: [castor-dev] Using Castor safely in Servlets >> > >> > Hi - >> > >> > I was able to get rid of some of my more frustrating problems when I >> > realized that I was trying to use Castor in the wrong situation (eg, >> > JSPs >> > instead of Servlets). However, I recall from the Castor website that >> > the >> > libraries are not thread safe. Servlet code must be. >> > >> > My question: how can I use Castor in a threadsafe way? Is there an >> > appropriate variable or variables I can synchronize on? Would it be the >> > JDO >> > object? The Database? The individual mapped objects? >> > >> > One example of what I must do is fetch an object from the database via >> > an >> > OQL query, change one or more fields, and then commit() the changes. >> > Where >> > should I use synchronize to make this threadsafe? >> > >> > Any pointers to more detailed docs about Castor and threading would be >> > greatly appreciated. >> > >> > >> > Thanks, >> > _________________________________ >> > >> > Robert Kent - (617) 413-3510 >> > http://www.rjk-comm.com/ >> > _________________________________ >> > >> > ----------------------------------------------------------- >> > If you wish to unsubscribe from this mailing, send mail to >> > [EMAIL PROTECTED] with a subject of: >> > unsubscribe castor-dev >> > >> > >> > >> > -- >> > >> > This e-mail is confidential and is intended for the named recipient only. >> > If >> > you receive it in error please destroy the message and all copies. 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Thank you for your compliance. >>Copyright (c) 2003 CIGNA >> >>++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ >> >>----------------------------------------------------------- >>If you wish to unsubscribe from this mailing, send mail to >>[EMAIL PROTECTED] with a subject of: >> unsubscribe castor-dev > >----------------------------------------------------------- >If you wish to unsubscribe from this mailing, send mail to >[EMAIL PROTECTED] with a subject of: > unsubscribe castor-dev > Dinesh Cell:703-725-4153 Email:[EMAIL PROTECTED] Web Site:http://www.trailblazingsolutions.com/dinesh The significant problems we face cannot be solved by the same level of thinking that created them - Albert Einstein ----------------------------------------------------------- If you wish to unsubscribe from this mailing, send mail to [EMAIL PROTECTED] with a subject of: unsubscribe castor-dev
