Re: [WebDNA] Re: exclusivelock
This WebDNA talk-list message is from 2011
It keeps the original formatting.
numero = 107017
interpreted = N
texte = I went back to re-read Grant's comment. Is he or are you saying that webdna does not handle its own threads in a coherent way or that webdna versus other programs presents a problem or both? I thought webdna would handle multiple accesses of a db no problem. I had thought exclusivelock was more for transaction-like database access to ensure inconsistent changes were not made (which I do not need yet). How would you test this exclusive lock scenario? Perhaps a lock via a 10-20 second loop and then hit the db via another script? Bill On Thu, Jul 21, 2011 at 10:33 AM, Aaron Michael Kaczmarek
wrote: > You got me on the hook! > > On 7/21/11 10:16 AM, Govinda wrote: >> >> Great questions Ken! >> I would also really like to read a definitive (more comprehensive) artic= le >> on that context. >> >> -Govinda >> >> >> On 2011-07-21, at 7:24 AM, Kenneth Grome wrote: >> >>>> Should I use exclusivelock on a db I want to replace? >>> >>> Are there other reasons why I should not use exclusivelock >>> as shown in the example below? >>> >>> Are there better ways to insure that this.db gets replaced >>> completely in RAM and on disk before the next visitor >>> requests a page that opens this.db again? >>> >>> Does anyone have a clue about how exclusivelock actually >>> works? =A0For example, can WebDNA acquire an exclusivelock on >>> a database that is closed? =A0Or does it have to open the db >>> in order to acquire the lock? >>> >>> What happens when a db is open when the exclusivelock is >>> acquired? =A0Can the db be closed and the file deleted inside >>> the exclusivelock context? >>> >>> Sorry if these questions seem anal, but using exclusivelock >>> at all suggests that we need to do something critically >>> important to the db, and if it doesn't work the way we think >>> it does, we could be making really bad assumptions and >>> possibly putting our data at risk. >>> >>> I never used exclusivelock before, and it seems that not >>> many other people have either. =A0But after Grant's post last >>> week I get the feeling that we should be using it in a lot >>> of situations where we are not. =A0So I'm just trying to get a >>> clearl understanding of its limitations, and how it actually >>> works. >>> >>> Sincerely, >>> Kenneth Grome >>> >>> >>> >>>> Should I use exclusivelock on a db I want to replace? =A0Is >>>> this the proper way to use exclusivelock? >>>> >>>> [exclusivelock db=3Dthis.db] >>>> [closedatabase this.db] >>>> [deletefile this.db] >>>> [copyfile from=3Dnew.db&to=3Dthis.db] >>>> [/exclusivelock] >>>> >>>> ... or does exclusivelock hold this.db OPEN thus >>>> preventing it from closing and therefore preventing it >>>> from being replaced by the new.db? >>>> >>>> Sincerely, >>>> Kenneth Grome >> >> --------------------------------------------------------- >> This message is sent to you because you are subscribed to >> the mailing list. >> To unsubscribe, E-mail to: >> archives: http://mail.webdna.us/list/talk@webdna.us >> Bug Reporting: support@webdna.us > > --------------------------------------------------------- > This message is sent to you because you are subscribed to > the mailing list . > To unsubscribe, E-mail to: > archives: http://mail.webdna.us/list/talk@webdna.us > Bug Reporting: support@webdna.us >
Associated Messages, from the most recent to the oldest:
I went back to re-read Grant's comment. Is he or are you saying that webdna does not handle its own threads in a coherent way or that webdna versus other programs presents a problem or both? I thought webdna would handle multiple accesses of a db no problem. I had thought exclusivelock was more for transaction-like database access to ensure inconsistent changes were not made (which I do not need yet). How would you test this exclusive lock scenario? Perhaps a lock via a 10-20 second loop and then hit the db via another script? Bill On Thu, Jul 21, 2011 at 10:33 AM, Aaron Michael Kaczmarek wrote: > You got me on the hook! > > On 7/21/11 10:16 AM, Govinda wrote: >> >> Great questions Ken! >> I would also really like to read a definitive (more comprehensive) artic= le >> on that context. >> >> -Govinda >> >> >> On 2011-07-21, at 7:24 AM, Kenneth Grome wrote: >> >>>> Should I use exclusivelock on a db I want to replace? >>> >>> Are there other reasons why I should not use exclusivelock >>> as shown in the example below? >>> >>> Are there better ways to insure that this.db gets replaced >>> completely in RAM and on disk before the next visitor >>> requests a page that opens this.db again? >>> >>> Does anyone have a clue about how exclusivelock actually >>> works? =A0For example, can WebDNA acquire an exclusivelock on >>> a database that is closed? =A0Or does it have to open the db >>> in order to acquire the lock? >>> >>> What happens when a db is open when the exclusivelock is >>> acquired? =A0Can the db be closed and the file deleted inside >>> the exclusivelock context? >>> >>> Sorry if these questions seem anal, but using exclusivelock >>> at all suggests that we need to do something critically >>> important to the db, and if it doesn't work the way we think >>> it does, we could be making really bad assumptions and >>> possibly putting our data at risk. >>> >>> I never used exclusivelock before, and it seems that not >>> many other people have either. =A0But after Grant's post last >>> week I get the feeling that we should be using it in a lot >>> of situations where we are not. =A0So I'm just trying to get a >>> clearl understanding of its limitations, and how it actually >>> works. >>> >>> Sincerely, >>> Kenneth Grome >>> >>> >>> >>>> Should I use exclusivelock on a db I want to replace? =A0Is >>>> this the proper way to use exclusivelock? >>>> >>>> [exclusivelock db=3Dthis.db] >>>> [closedatabase this.db] >>>> [deletefile this.db] >>>> [copyfile from=3Dnew.db&to=3Dthis.db] >>>> [/exclusivelock] >>>> >>>> ... or does exclusivelock hold this.db OPEN thus >>>> preventing it from closing and therefore preventing it >>>> from being replaced by the new.db? >>>> >>>> Sincerely, >>>> Kenneth Grome >> >> --------------------------------------------------------- >> This message is sent to you because you are subscribed to >> the mailing list. >> To unsubscribe, E-mail to: >> archives: http://mail.webdna.us/list/talk@webdna.us >> Bug Reporting: support@webdna.us > > --------------------------------------------------------- > This message is sent to you because you are subscribed to > the mailing list . > To unsubscribe, E-mail to: > archives: http://mail.webdna.us/list/talk@webdna.us > Bug Reporting: support@webdna.us >
William DeVaul
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