The client-side IP driver is a Clarion FILE
driver, but instead of using local physical files for storing data it
communicates over IP to a server where the physical data is processed. The
SoftVelocity IP Data Server is a Win32 service running on the machine where the
physical data files are located and accessed.
The IP
Driver is compatible with any application written using either the Clarion or
ABC template chains. The client
application can make use of the entire
Clarion runtime library, any Windows API functions, ActiveX controls,
any
supported FILE driver, both MDI and SDI windows, and any 3rd Party tool
set. The Client application can be configured to be 100% remote database client,
or can use a mix of both local physical files and remote data files. The Client
application can also use a mix of different FILE drivers.
The IP
Driver and Server (IPDS) has three major components:
• The IP
Driver, which becomes part of the client application, requests and accepts data
from the IP Data Server.
The communication stream can be performed with or
without SSL (Secure Socket Layer) support.
• The IP Data Server accepts
requests for data from the client, processes the request and returns the data.
• Remote Administrator: the Remote Administration Console application is
designed for administrators, and allows
you to Shutdown the Server,
Register/UnRegister Data Manager DLLs, monitor connections, specify
USER
accounts and permissions for tables, and more.
To
enable a Clarion application to function as a remote database client, there are
only three steps; adding the IP Client extension template to the client
application(s), the creation of a server side Data Manager DLL, and registering
the Data Manager DLL on the server.
Version
2.0 is focused on peformance enhancements, with the goal of making the driver
perform very well over low bandwidth WAN and ASDL connections, and even using a
dial-up connection. The new version implements Server-side VIEWs, which means
that when the client app opens the VIEW as defined in the app, the VIEW is sent
to the server where it is dynamically reconstructed. Server side VIEWs are a
great advance over version 1.x because of the significant reduction in network
traffic. In version 2 all VIEW filtering is done on the server, and only the
fields from the VIEW are sent back to the client. This is all accomplished
without changing any of your code, even code that uses filters based on
client-side variables!
The
second major advance in IPD 2 is Multiple Request Packets (MRP). MRP's are a new
technique that transmits a single packet from the server to client that contains
multiple records. The result is much less network traffic, and much faster
Browses and Reports.
You
don't need any new code to make use of Server-side VIEWs and MRPs. The
Server-side Views and the MRP support is completely automatic. The impact of
these two new features is a much faster application, with the most dramatic
improvements in Browses, Reports and Processes.
What file drivers does the IPDS
support?
You can
use any Clarion file driver (Btrieve, Clarion, TopSpeed, Ascii,
etc).
The
In-Memory driver operates in RAM on the local client so it cannot be IP-enabled,
however you can execute server-side code that manipulates IMDD
tables.
What changes do I have to make to my .App to access a
table over IP?
All of the changes are implemented with a global extension template. You
do not have to make any changes to your Data Dictionary. The IPDS template
supports using a mix of remote IP-enables tables and local physical
tables.
How long does it take to IP-enable an
application
There is
a chapter in the manual titled "An IP-enabled Application in Ten Minutes (or
less)", you can review that to get a good idea of the necessary steps. In
general you only need to add the extension template to each .App file that
comprises your application.
What 3rd party tools are compatible with the
IPDS?
Your
application is unchanged except that file access is over IP, so any 3rd party
tool, Windows API or embedded OCX will perform exactly as before IP-enabling
your application.
Is FileManager3 compatible with the IPDS?
Yes,
FileManager3 which must run on the server has been certified as compatible with
the IPDS.
Can I distribute the IP Data Server
royalty-free?
Yes, as
with all Clarion products there are no royalties on distribution.
Does the IPDS support BLOBs and Memo
fields?
Yes, both data types are supported and there is support for the /NoMemo
switch.
What are the advantages of client/server?
Client/Server computing offers some benefits over standalone
models:
*
Stability - If a client machine crashes or gets disconnected from the server,
other users are not affected, and there is a much smaller chance of database
corruption.
* Distributed Workload - When you run a client/server application you
have two computers working on a single task.
* Security - the IP Data server
can enforce user logon and file access security.
* Performance - The IPDS can
be used as a fast and simple method to solve the speed problems that are related
to the oplocks settings that MS
introduced starting with Win2k. Since all
I/O is done on the server the Windows
OS has no reason to start its
locking.
Can my client app invoke remote procedures on the
server?
Yes, the
IP Driver/Server support a special syntax of the SEND command that can be used
to invoke a remote procedure.
What does the application architecture look
like?
The
Clarion application program is linked with the IP Driver. When the client
application issues an OPEN(file) for an IP-enabled file, the IP driver transmits
a request to the IP data server to load the specified Data Manager and OPEN the
file. If the request is successful the IP Data Server spawns a new thread for
that client session.
More
questions? We
suggest that you download and review the IP Driver and Server manual
