Author: Rahul Bhargava
All these repositories then stay in sync with each other, regardless of
where updates occur. Consistency across repositories is guaranteed no
matter what – communication links going down, hardware failures, process failures.
Deployment is a breeze, with no changes to the CVS server, the CVS repository or the CVS clients. All CVS features work as before, and you get unparalleled reliability and performance. Intrigued? Read our architecture white paper to see how it works
http://www.wandisco.com/cvs .
Key benefits include :
1. Transparent Gateway
The replicator acts as a gateway between CVS clients and CVS server. It intercepts CVS protocol.
CVS Clients don’t need any configuration change. If the Gateway is listening on the standard CVS port, even CVSROOT for clients doesn’t need to change.
Full CVS protocol is supported including SSH, CVS_RSH, Glib compression.
2. Local Reads
CVS commands like checkout, update, status, log are read commands. They always pass through the Replicator to the local CVS server with no WAN traffic.
CVS users typically do a lot of repository browsing, be it checkouts or looking at change logs. Replicator always executes CVS read commands locally ensuring low latencies for the end user. For an offshore site, this is a huge win.
3. Rotating Quorum
Quorum is a minimal set of CVS nodes that must be available for a write command. This amazing feature makes it possible to implement a follow-the-sun development model. Offsite developers even when they execute CVS write commands like check-in, tag, branching, do not see WAN latencies! It’s as if they have a local autonomous CVS server. Patent-pending Rotating Quorum technology ensures that repositories remain in sync.
4. Multisite, Active-Active Architecture
Replicator is the only game in town, that lets you setup “write-anywhere” active CVS replicas without using half-way solutions like branching and merge.
Load on any given CVS server is reduced, as read commands can be scaled to multiple CVS servers. This provides better responsiveness to the end CVS user.
There is no upper limit on how many active replicas you can setup. You could setup one for each R&D site.
5. Reduced TCP Chatter
CVS protocol is text based and verbose. A typical write command like check-in incurs atleast 4.5 network round trips. Our Replicators talk via an optimized binary protocol.
We reduce the WAN traffic to 1 round trip. That’s how long a CVS client may have to wait to complete a write with our Replicator. Of course with Rotating Quorum the CVS client’s WAN latency can be reduced to 0!!
