The SpectrumSCM Proxy offers a solution for distributed development in bandwidth
constrained environments. If the SpectrumSCM server is in a remote location and
the available bandwidth between the local and remote ends is small, operations that
require a file to be transferred across the wire can exhibit considerable lag. The
proxy tries to address this issue by maintaining a "Local Cache" which reduces the
number of file transfer operations across the WAN. Here is an example scenario:
Assume that the Clients C1 and C2 are on a 100BaseT LAN and the WAN pipe is a < 256 kbps pipe. In the absence of the Proxy, the clients directly interact with the server and all file transfer operations happen over W. This can be slow and inefficient considering the fact that the bandwidth is small. In such situations, whenever a client downloads a file from the server across the wire, other clients who need the same file in the future can make use of the file downloaded by the first client. Assuming that the file contents have not changed, the clients can bypass the server and get the file from within the LAN, which makes the operation extremely fast. Thus over a period of time, files downloaded from the server can be used to serve similar requests from different clients, provided that the file contents have not changed. This is handled by the SpectrumSCM Proxy, which maintains a passive cache for files downloaded from the server.
Whenever a client needs a file from the server, it routes the request through the proxy. The proxy checks its cache to see if it has the file that is being requested. If it determines that the file being requested and the cached copy are the same, it serves the request without downloading the file from the server. Thus it becomes a local file transfer. If it is a miss, it downloads the file from the server, passes it on to the client and caches it for future use. Over a period of time, the number of hits will surpass the number of misses making checkout operations considerably fast. The proxy not only caches head revisions but also caches previous versions, which is extremely useful during release extracts and extract files by version/CRs.
In addition to the obvious use in bandwidth constrained networks, the user can start a proxy on his/her own box and thus use the proxy as a local cache.
Starting the SpectrumSCM ProxyWindows:
Goto the SpectrumSCM menu under the Start menu and choose the Start Proxy menu item OR
Open a command prompt window and go to the <SpectrumSCM Install>/bin directory. Use the startProxy.bat script
Open a terminal window and go to the <SpectrumSCM Install>/bin directory. Use the startProxy script
The startProxy script uses the following arguments:
The proxy log files are maintained under <specified cache dir>/logs directory
Stopping the SpectrumSCM ProxyWindows:
Goto the SpectrumSCM menu under the Start menu and choose the Stop Proxy menu item OR
Open a command prompt window and go to the <SpectrumSCM Install>/bin directory. Use the stopProxy.bat script
Open a terminal window and go to the <SpectrumSCM Install>/bin directory Use the stopProxy script
The stopProxy script uses the following arguments:
How to use the SpectrumSCM Proxy
For further assistance, send a mail to firstname.lastname@example.org or contact Spectrum Software at 770.448.8662. For additional information on SpectrumSCM please visit our website at www.spectrumscm.com.