Re: [WebDNA] Timer

This WebDNA talk-list message is from

2009


It keeps the original formatting.
numero = 101733
interpreted = N
texte = A way to do that would be to add a "timestamp" to a small "witness database" with only one record, any time the main database or the file is updated (you must add a small [Replace] command to update the last value). Then you can compare the last counter value with the last one you had and send the response to your users. A WebDNA trigger should be fine. You could also flag the event with just a "1" in your witness database, then reset it to "0" each time you send the notification to your users. You can also use the [FileInfo] and [ModTime] but it will not work with the WebDNA database, since it is not written to disk. I guess this would also be slower. There are many ways to do this. chris On Jan 3, 2009, at 2:51, Jason Adams wrote: > Sorry for the delayed response, Christmas holidays and all. Happy New > Year everyone! > > Dylan, after reading your response I think I need to explain in more > detail. I need the software to check on the status of a database and a > plain text file every few seconds. When the software detects that the > database or the file has changed, it must send a response to all > connected visitors. > > I'll be keeping connections open to these visitors for the sole > purpose of sending them an update every few seconds. An update will be > sent whether or not something has changed since the last update. This > is necessary to keep visitors informed that they are still online and > connected. > > I've read that triggers are buggy so I don't think I should rely on > them until they are fixed. This checking and updating capability is > absolutely critical to the application, so this may mean it should be > done with cron. If this software can interface with cron and run cron > events can someone post a code example to help me get started? > > I run Linux servers exclusively, and I could have hundreds of servers > running this distributed online system at any given moment. They are > generic servers, not all the same OS and not all the same hosts, so > I'll need software that works on all of them. From what I've read it > looks like the company is building such a new version for Linux so > maybe this is good timing. > > ----------- > Jason > > > > On 12/21/08, Dylan Wood wrote: >> Jason- >> >> As long as the event your talking about yields some sort of evidence >> that it occurred, you can use webdna to detect that. then trigger >> your >> own process whatever it may be. WebDNA can read files and folders, >> so >> if the event you are talking about impacts the file system, you >> should >> be able to detect it. >> >> On Dec 21, 2008, at 5:28 AM, Jason Adams wrote: >> >>> Hello I'm new here and new to WebDNA. Hoping to get some help from >>> anyone who knows. Can WebDNA detect server events then send data to >>> all logged in visitors incrementally? >>> >>> I may need to build a site that sends data from the server >>> incrementally, every second or every few seconds, if it has changed >>> since the last incrementing event. Wondering if WebDNA can do this? >>> >>> ----------- >>> Jason >>> --------------------------------------------------------- >>> 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 >>> old archives: http://dev.webdna.us/TalkListArchive/ >> >> --------------------------------------------------------- >> 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 >> old archives: http://dev.webdna.us/TalkListArchive/ >> > --------------------------------------------------------- > 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 > old archives: http://dev.webdna.us/TalkListArchive/ Associated Messages, from the most recent to the oldest:

    
  1. Re: [WebDNA] Timer (Patrick McCormick 2009)
  2. Re: [WebDNA] Timer ("Jason Adams" 2009)
  3. Re: [WebDNA] Timer ("Psi Prime, Matthew A Perosi " 2009)
  4. Re: [WebDNA] Timer (Terry Wilson 2009)
  5. Re: [WebDNA] Timer (Terry Wilson 2009)
  6. Re: [WebDNA] Timer (Donovan Brooke 2009)
  7. Re: [WebDNA] Timer ("Jason Adams" 2009)
  8. Re: [WebDNA] Timer (christophe.billiottet@webdna.us 2009)
  9. Re: [WebDNA] Timer ("Jason Adams" 2009)
  10. Re: [WebDNA] Timer (Dylan Wood 2008)
  11. [WebDNA] Timer ("Jason Adams" 2008)
A way to do that would be to add a "timestamp" to a small "witness database" with only one record, any time the main database or the file is updated (you must add a small [replace] command to update the last value). Then you can compare the last counter value with the last one you had and send the response to your users. A WebDNA trigger should be fine. You could also flag the event with just a "1" in your witness database, then reset it to "0" each time you send the notification to your users. You can also use the [fileinfo] and [ModTime] but it will not work with the WebDNA database, since it is not written to disk. I guess this would also be slower. There are many ways to do this. chris On Jan 3, 2009, at 2:51, Jason Adams wrote: > Sorry for the delayed response, Christmas holidays and all. Happy New > Year everyone! > > Dylan, after reading your response I think I need to explain in more > detail. I need the software to check on the status of a database and a > plain text file every few seconds. When the software detects that the > database or the file has changed, it must send a response to all > connected visitors. > > I'll be keeping connections open to these visitors for the sole > purpose of sending them an update every few seconds. An update will be > sent whether or not something has changed since the last update. This > is necessary to keep visitors informed that they are still online and > connected. > > I've read that triggers are buggy so I don't think I should rely on > them until they are fixed. This checking and updating capability is > absolutely critical to the application, so this may mean it should be > done with cron. If this software can interface with cron and run cron > events can someone post a code example to help me get started? > > I run Linux servers exclusively, and I could have hundreds of servers > running this distributed online system at any given moment. They are > generic servers, not all the same OS and not all the same hosts, so > I'll need software that works on all of them. From what I've read it > looks like the company is building such a new version for Linux so > maybe this is good timing. > > ----------- > Jason > > > > On 12/21/08, Dylan Wood wrote: >> Jason- >> >> As long as the event your talking about yields some sort of evidence >> that it occurred, you can use webdna to detect that. then trigger >> your >> own process whatever it may be. WebDNA can read files and folders, >> so >> if the event you are talking about impacts the file system, you >> should >> be able to detect it. >> >> On Dec 21, 2008, at 5:28 AM, Jason Adams wrote: >> >>> Hello I'm new here and new to WebDNA. Hoping to get some help from >>> anyone who knows. Can WebDNA detect server events then send data to >>> all logged in visitors incrementally? >>> >>> I may need to build a site that sends data from the server >>> incrementally, every second or every few seconds, if it has changed >>> since the last incrementing event. Wondering if WebDNA can do this? >>> >>> ----------- >>> Jason >>> --------------------------------------------------------- >>> 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 >>> old archives: http://dev.webdna.us/TalkListArchive/ >> >> --------------------------------------------------------- >> 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 >> old archives: http://dev.webdna.us/TalkListArchive/ >> > --------------------------------------------------------- > 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 > old archives: http://dev.webdna.us/TalkListArchive/ christophe.billiottet@webdna.us

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