sharing data between sites - xharbour

Claudio,

Just one idea:
~ a program does daily data export from the local database
~ other program does one or more daily data import operations in the local
database
~ each daily file sent or requested programmatically for replication to all
other locations will have a specific name like "xxyyyymmdd" where "xx"
identifies the location from where the data is coming from and "yyyymmdd"
the date when the data was exported from the local database
~ all tables which contain data that needs to be exported daily will be
extended with a TmeStamp column
~ the TimeStamp column will be always exported from the local database
together with the related data
~ "xx" and the TimeStamp together can serve as unique key for the data
import program

Also a Happy New Year,

Ella




<cherszage@gmail.com> wrote in message
news:889fcf33-c51a-42b6-9fe0-a5ec7b3d90ee@s27g2000hsb.googlegroups.com...
> Hi guys
> This is not a post about an error but I need help in a programming
> solution.
> I need to test the following situation:
> 2 or 3 sites conected to the internet, where some data can be input by
> an user in any of them, and need this data available in the other
> sites.
> The idea is to have the data locally in each site, not in a central
> server. It's not necessary to have an instant update, maybe a once a
> day process would be ok.
> If anyone can guide me through this, show an example or tell me where
> I can read about it would be really very appreciated.
> Thank you all and wish you a great 2008 !!!
> Claudio

Dear cherszage:

<cherszage@gmail.com> wrote in message
news:889fcf33-c51a-42b6-9fe0-a5ec7b3d90ee@s27g2000hsb.googlegroups.com...
> Hi guys
> This is not a post about an error but I need help in
> a programming solution.
> I need to test the following situation:
> 2 or 3 sites conected to the internet, where some
> data can be input by an user in any of them, and
> need this data available in the other sites.

A small modification to Ella Stern's procedure:
- write out only changed records, not a full database export. Be
a simple matter to change the DateTime field for that record if
the data changes, and compare these timestamps to the DateTime of
the last "broadcast".

You will need to consider what happens when two users update the
same record.

You will need to allow for a user to initiate a manual broadcast.

If the data is sensitive, you could zip it and encode the zip
with a password. (This can be done via xHarbour too. Search
here for sample code.)

You can then broadcast via FTP to registered sites (search here
for sample code).

Have you given any thought as to how your code will manage the "2
or 3 sites" should the number of sites increase?

David A. Smith

Thanks Ella & David for your answers.
The time stamp thing is clear enough.
Respect to broadcasting the new data or changes, I don't feel FTP is a
good solution if, as you David stated, the number of sites increases.
One idea I had is finding a solution that refreshes data on demand,
but also think that it won't work with more sites integrated.
Other idea is having a background application in each site sending and
receiving updates, but actually don't know how to handle it.
Thank you again for your guidance and help.
Claudio


On Dec 29, 1:24 pm, "N:dlzc D:aol T:com \(dlzc\)" <dl...@cox.net>
wrote:
> Dear cherszage:
>
> <chersz...@gmail.com> wrote in message
>
> news:889fcf33-c51a-42b6-9fe0-a5ec7b3d90ee@s27g2000hsb.googlegroups.com...
>
> > Hi guys
> > This is not a post about an error but I need help in
> > a programming solution.
> > I need to test the following situation:
> > 2 or 3 sites conected to the internet, where some
> > data can be input by an user in any of them, and
> > need this data available in the other sites.
>
> A small modification to Ella Stern's procedure:
> - write out only changed records, not a full database export.  Be
> a simple matter to change the DateTime field for that record if
> the data changes, and compare these timestamps to the DateTime of
> the last "broadcast".
>
> You will need to consider what happens when two users update the
> same record.
>
> You will need to allow for a user to initiate a manual broadcast.
>
> If the data is sensitive, you could zip it and encode the zip
> with a password.  (This can be done via xHarbour too.  Search
> here for sample code.)
>
> You can then broadcast via FTP to registered sites (search here
> for sample code).
>
> Have you given any thought as to how your code will manage the "2
> or 3 sites" should the number of sites increase?
>
> David A. Smith

"Robot programs" (bots) are executables started as services which run again
and again in definite time periods - maybe the "last timestamp sent out
successfully" can be memorized im a column of a table which contains one
line of data for each location, including the local one marked somehow
specially.

Best regards,

Ella

<cherszage@gmail.com> wrote in message
news:0ae3f87f-a4ac-4d1d-afb0-faf324212b09@e23g2000prf.googlegroups.com...
Thanks Ella & David for your answers.
The time stamp thing is clear enough.
Respect to broadcasting the new data or changes, I don't feel FTP is a
good solution if, as you David stated, the number of sites increases.
One idea I had is finding a solution that refreshes data on demand,
but also think that it won't work with more sites integrated.
Other idea is having a background application in each site sending and
receiving updates, but actually don't know how to handle it.
Thank you again for your guidance and help.
Claudio


On Dec 29, 1:24 pm, "N:dlzc D:aol T:com \(dlzc\)" <dl...@cox.net>
wrote:
> Dear cherszage:
>
> <chersz...@gmail.com> wrote in message
>
> news:889fcf33-c51a-42b6-9fe0-a5ec7b3d90ee@s27g2000hsb.googlegroups.com...
>
> > Hi guys
> > This is not a post about an error but I need help in
> > a programming solution.
> > I need to test the following situation:
> > 2 or 3 sites conected to the internet, where some
> > data can be input by an user in any of them, and
> > need this data available in the other sites.
>
> A small modification to Ella Stern's procedure:
> - write out only changed records, not a full database export. Be
> a simple matter to change the DateTime field for that record if
> the data changes, and compare these timestamps to the DateTime of
> the last "broadcast".
>
> You will need to consider what happens when two users update the
> same record.
>
> You will need to allow for a user to initiate a manual broadcast.
>
> If the data is sensitive, you could zip it and encode the zip
> with a password. (This can be done via xHarbour too. Search
> here for sample code.)
>
> You can then broadcast via FTP to registered sites (search here
> for sample code).
>
> Have you given any thought as to how your code will manage the "2
> or 3 sites" should the number of sites increase?
>
> David A. Smith

Dear Claudio:

On Dec 30, 9:30 pm, chersz...@gmail.com wrote:
> Thanks Ella & David for your answers.
> The time stamp thing is clear enough.
> Respect to broadcasting the new data or changes, I don't
> feel FTP is a good solution if, as you David stated, the
> number of sites increases.

There is no reason it should be a problem without a solution. If they
always have internet access.
You could:
- have a central data site, and all remote sites send / receive with
this site. (central control)
- have each site transmit to other site, and receive from every other
site. (chaos)
- have each site transmit its changes to two other sites, and receive
changes only from those two sites. (maquis control)

> One idea I had is finding a solution that refreshes data
> on demand, but also think that it won't work with more
> sites integrated.

Should not be a problem, if they are all in the same (or similar) time
zone (or the application runs 24/7).

> Other idea is having a background application in each
> site sending and receiving updates, but actually don't
> know how to handle it.

You could have a separate xHarbour application do this job. It is
loaded by WinDoze in the Startup folder. Be sure and allow the
application to update the list of sites it is to communicate with, and
when is the best time to contact those sites.

David A. Smith

cherszage@gmail.com ha scritto:
> Hi guys
> This is not a post about an error but I need help in a programming
> solution.
> I need to test the following situation:
> 2 or 3 sites conected to the internet, where some data can be input by
> an user in any of them, and need this data available in the other
> sites.
> The idea is to have the data locally in each site, not in a central
> server. It's not necessary to have an instant update, maybe a once a
> day process would be ok.
> If anyone can guide me through this, show an example or tell me where
> I can read about it would be really very appreciated.
> Thank you all and wish you a great 2008 !!!
> Claudio
What about a cgi application able to manage 2 kind of request:
1 request from user
2 request from another server
Upon a request from another server it simply sends the data.
Upon a request from an user it first sends a server request to the other
2 servers, then integrates data with his own data and outputs the whole set.
Dan

On Jan 2, 1:57 pm, "D.Campagna" <ynnadre...@tiscalinet.it> wrote:
> chersz...@gmail.com ha scritto:> Hi guys
> > This is not a post about an error but I need help in a programming
> > solution.
> > I need to test the following situation:
> > 2 or 3 sites conected to the internet, where some data can be input by
> > an user in any of them, and need this data available in the other
> > sites.
> > The idea is to have the data locally in each site, not in a central
> > server. It's not necessary to have an instant update, maybe a once a
> > day process would be ok.
> > If anyone can guide me through this, show an example or tell me where
> > I can read about it would be really very appreciated.
> > Thank you all and wish you a great 2008 !!!
> > Claudio
>
> What about a cgi application able to manage 2 kind of request:
> 1 request from user
> 2 request from another server
> Upon a request from another server it simply sends the data.
> Upon a request from an user it first sends a server request to the other
> 2 servers, then integrates data with his own data and outputs the whole set.
> Dan

Hi Dan
Thanks for your answer.
I'm not so sure to understand this idea of the 2 servers managing
requests, can you please explain it a little further ?
It will also be helpful for me to get some guide on writting an app
that sends/receives data from another.
Thanks again
Claudio

On Jan 3, 12:51 pm, chersz...@gmail.com wrote:
> On Jan 2, 1:57 pm, "D.Campagna" <ynnadre...@tiscalinet.it> wrote:
>
>
>
>
>
> > chersz...@gmail.com ha scritto:> Hi guys
> > > This is not a post about an error but I need help in a programming
> > > solution.
> > > I need to test the following situation:
> > > 2 or 3 sites conected to the internet, where some data can be input by
> > > an user in any of them, and need this data available in the other
> > > sites.
> > > The idea is to have the data locally in each site, not in a central
> > > server. It's not necessary to have an instant update, maybe a once a
> > > day process would be ok.
> > > If anyone can guide me through this, show an example or tell me where
> > > I can read about it would be really very appreciated.
> > > Thank you all and wish you a great 2008 !!!
> > > Claudio
>
> > What about a cgi application able to manage 2 kind of request:
> > 1 request from user
> > 2 request from another server
> > Upon a request from another server it simply sends the data.
> > Upon a request from an user it first sends a server request to the other
> > 2 servers, then integrates data with his own data and outputs the whole set.
> > Dan
>
> Hi Dan
> Thanks for your answer.
> I'm not so sure to understand this idea of the 2 servers managing
> requests, can you please explain it a little further ?
> It will also be helpful for me to get some guide on writting an app
> that sends/receives data from another.
> Thanks again
> Claudio- Hide quoted text -
>
> - Show quoted text -

Hi guys
I finally decided that the best soluction will be to have a central
server that receives/sends data to the other sites.
Now I must ask you for some help and/or examples about it, building an
application which can ask the others to send new or changed data and
save it, and send these new data to the others.
Thanks again
Claudio

Dear cherszage:

<cherszage@gmail.com> wrote in message
news:cddc5ab9-f35b-4b63-b015-879e0e03263b@c4g2000hsg.googlegroups.com...
....
> I finally decided that the best soluction will be to
> have a central server that receives/sends data to
> the other sites. Now I must ask you for some
> help and/or examples about it,

Best to search this newsgroup for "FTP", and look in your
xharbour directory for files with "ftp" in their name.

David A. Smith