Peer-to-peer architecture with no single point of failure. Not master-slave or multi-master . Repositories at every site are fully readable and writeable. Subversion repositories connected over a WAN synchronize automatically with each write operation. Developers at all locations experience LAN speed performance over a WAN for both read and write operations. Built-in hot backup and automated disaster recovery features make third party solutions completely unnecessary. Transparent implementation doesn’t change Subversion’s behavior, so there’s no retraining. Key Features

Peer-to-peer architecture with no single point of failure.

Not master-slave or multi-master .

Repositories at every site are fully readable and writeable.

Subversion repositories connected over a WAN synchronize automatically with each write operation.

Developers at all locations experience LAN speed performance over a WAN for both read and write operations.

Built-in hot backup and automated disaster recovery features make third party solutions completely unnecessary.

Transparent implementation doesn’t change Subversion’s behavior, so there’s no retraining.

Replicator implemented as a transparent network proxy at each site. Normally installed on the same server as Apache at each location. Listens on same port clients use to connect to Subversion: Port 80 for HTTP. Port 443 for HTTPS. No client configuration changes. No changes to Subversion server. Architecture

Replicator implemented as a transparent network proxy at each site.

Normally installed on the same server as Apache at each location.

Listens on same port clients use to connect to Subversion:

Port 80 for HTTP.

Port 443 for HTTPS.

No client configuration changes.

No changes to Subversion server.

LAN-speed performance over a WAN results from a combination of Subversion MultiSite’s: Active-active replication capability: Subversion servers become active nodes on a network. Each node works cooperatively with its peers to agree on transaction ordering. Each node’s repository becomes an exact replica of every other. Quorum Configuration Only a quorum of nodes have to agree on transaction ordering. Quorum based on distribution of users/activity across sites for best performance . Network Architecture Minimizes number of WAN roundtrips and bandwidth usage. Architecture

LAN-speed performance over a WAN results

from a combination of Subversion MultiSite’s:

Active-active replication capability:

Subversion servers become active nodes on a network.

Each node works cooperatively with its peers to agree on transaction ordering.

Each node’s repository becomes an exact replica of every other.

Quorum Configuration

Only a quorum of nodes have to agree on transaction ordering.

Quorum based on distribution of users/activity across sites for best performance .

Network Architecture

Minimizes number of WAN roundtrips and bandwidth usage.

How it works: The replicator generates a proposal (header) for each write at its location and sends it to its peers. The proposal contains a globally unique transaction id and other data used to determine if conflicts exist. The proposal’s unique transaction id is used at every location to guarantee consistent transaction order. Users experience LAN speed performance. Once agreement is received from a quorum of nodes, the write goes forward at the site where it originated. No waiting for other sites to complete the write. Agreement takes less than half a second between US and India over a typical E-1 line. All reads are local and generate no WAN traffic. Active-Active Replication

How it works:

The replicator generates a proposal (header) for each write at its location and sends it to its peers.

The proposal contains a globally unique transaction id and other data used to determine if conflicts exist.

The proposal’s unique transaction id is used at every location to guarantee consistent transaction order.

Users experience LAN speed performance.

Once agreement is received from a quorum of nodes, the write goes forward at the site where it originated.

No waiting for other sites to complete the write.

Agreement takes less than half a second between US and India over a typical E-1 line.

All reads are local and generate no WAN traffic.

Quorum Configuration How it works: Quorum configuration options: Majority - Only 51% of nodes required to respond to proposal. Distinguished Node – node used as tie-breaker with an even number of nodes Singleton - The Distinguished Node is the quorum . Ideal if one site has many more users and activity than others. Superior performance at the quorum site. Responses from remote nodes are not required at the Distinguished node No WAN traffic generated for agreement process . Writes get sent to other nodes after agreement process completes at distinguished node. Unanimous - Responses required from all nodes Follow-the-sun quorum rotation Optimizes performance for each region’s normal working hours.

How it works:

Quorum configuration options:

Majority - Only 51% of nodes required to respond to proposal.

Distinguished Node – node used as tie-breaker with an even number of nodes

Singleton - The Distinguished Node is the quorum .

Ideal if one site has many more users and activity than others.

Superior performance at the quorum site.

Responses from remote nodes are not required at the Distinguished node

No WAN traffic generated for agreement process .

Writes get sent to other nodes after agreement process completes at distinguished node.

Unanimous - Responses required from all nodes

Follow-the-sun quorum rotation

Optimizes performance for each region’s normal working hours.

Network Optimization How it works: Reduces network traffic and bandwidth usage and costs All reads are local and generate no WAN traffic Streaming on Persistent connection between servers Connection pooling used for multiplexing TCP 3-Way Handshake Eliminated Uses WANdisco’s own protocol over the WAN Eliminates normal Subversion chattiness over the WAN WAN roundtrip times are significantly reduced Overcomes WAN performance issues with HTTP WebDAV Protocol Entire commit with multiple files can be sent over one connection. Other solutions open and close connections for each file.

How it works:

Reduces network traffic and bandwidth usage and costs

All reads are local and generate no WAN traffic

Streaming on Persistent connection between servers

Connection pooling used for multiplexing

TCP 3-Way Handshake Eliminated

Uses WANdisco’s own protocol over the WAN

Eliminates normal Subversion chattiness over the WAN

WAN roundtrip times are significantly reduced

Overcomes WAN performance issues with HTTP WebDAV Protocol

Entire commit with multiple files can be sent over one connection.

Other solutions open and close connections for each file.

Demo

Built-in Backup and Recovery Active-Active replication delivers continuous hot backup by default. Subversion MultiSite leverages this to provide automated recovery. Catch up from any other live node on restart after a network outage or server crash. Maintains a database-like redo log/pending transaction journal for recovery. Split brain is impossible. Users can failover to another site’s Subversion server while theirs is down and continue working. Makes full 24x7 operation possible in a globally distributed environment. Servers can be taken offline for maintenance without disrupting user access. Third party disk mirroring solutions are completely unnecessary.

Active-Active replication delivers continuous hot backup by default.

Subversion MultiSite leverages this to provide automated recovery.

Catch up from any other live node on restart after a network outage or server crash.

Maintains a database-like redo log/pending transaction journal for recovery.

Split brain is impossible.

Users can failover to another site’s Subversion server while theirs is down and continue working.

Makes full 24x7 operation possible in a globally distributed environment.

Servers can be taken offline for maintenance without disrupting user access.

Third party disk mirroring solutions are completely unnecessary.

Server Versions Supported Subversion server versions 1.3 and above are supported. Backend Support: FSFS and Berkeley DB are supported. Supported Clients Subversion command line, SmartSVN, RapidSVN, TortoiseSVN, Subclipse, and any HTTP client that works with Subversion. System Requirements WANdisco for Subversion will run in any J2SE 1.5 or above compliant Java runtime environment. A minimum of 64 MB of RAM and 450MHz CPU is recommended for the server System Requirements

Server Versions Supported

Subversion server versions 1.3 and above are supported.

Backend Support:

FSFS and Berkeley DB are supported.

Supported Clients

Subversion command line, SmartSVN, RapidSVN, TortoiseSVN, Subclipse, and any HTTP client that works with Subversion.

System Requirements

WANdisco for Subversion will run in any J2SE 1.5 or above compliant Java runtime environment. A minimum of 64 MB of RAM and 450MHz CPU is recommended for the server

Unique technology allows distributed development teams to work as one at LAN-speed over a WAN, instead of working in silos. Dramatically reduces development time and cost. Peer-to-peer architecture with no single point of failure. All servers can be monitored and administered from a single location. Built-in continuous hot backup and self-healing capabilities eliminate risk in a disaster recovery scenario. Makes full 24X7 operation possible in a globally distributed environment. Transparent implementation eliminates retraining. Most cost effective multi-site solution available. Summary

Unique technology allows distributed development teams to work as one at LAN-speed over a WAN, instead of working in silos.

Dramatically reduces development time and cost.

Peer-to-peer architecture with no single point of failure.

All servers can be monitored and administered from a single location.

Built-in continuous hot backup and self-healing capabilities eliminate risk in a disaster recovery scenario.

Makes full 24X7 operation possible in a globally distributed environment.

Transparent implementation eliminates retraining.

Most cost effective multi-site solution available.