Robotics Service Bus

Spread 4.4 has just been released and contains some interesting features (less overhead for small messages, new protocol for highest performance, improved windows build system):

Available for download from here: http://www.spread.org/download.html

Spread 4.4.0 RC1 http://www.spread.org

Spread Concepts LLC is happy to announce the release of a
new release candidate version, 4.4.0 RC1, of the Spread toolkit.

The Spread 4.4 release is an important release that incorporates a new,
accelerated ring protocol.  This protocol is tailored for data center networks
and can provide 30%-50% higher throughput and 20-35% lower latency in modern
local area networks  This version also supports Spread's old ring protocol.

A new AcceleratedRing parameter has been added to Spread's configuration file.
If this parameter is set to true, then the accelerated ring protocol will be used.
If it is set to false, then the old ring protocol will be used.  If it is left
unspecified, then Spread will try to determine which protocol is likely better for
your environment.  If your configuration looks like it might be a LAN (i.e. - all
daemon IPs are in the same /16 network) rather than a WAN, then Spread will use
the accelerated protocol.  Otherwise, it will use the original protocol.  All the
daemons in a configuration must use the same ring protocol.  Daemons with different
protocols will refuse to communicate with one another.

A new AcceleratedWindow parameter, with a value between 0 and the value of the
PersonalWindow parameter, should be specified as a flow control parameter in the
spread.conf file.  The higher the parameter the more acceleration is expected --
up to a point.  The sample.spread.conf file included in this release has
example settings for these parameters that enable the Accelerated Ring
protocol, as well as a description of their functions.

The main new features of this release are:

1) Accelerated Ring protocol to improve both throughput and latency in local area networks.

2) Redesigned message-packing, reducing overhead for small messages.

3) Updated MSVS project files for Windows source builds.

4) Several bugfixes that make Spread less likely to exit under high loss.

5) Expanded and improved logging.

For details check the Readme.txt file.

This release does not include any API changes, so applications should
be able to be relinked or recompiled with the new Spread library without
changes.

The Spread toolkit provides a high performance messaging service
that is resilient to faults across local and wide area networks.
Spread functions as a unified message bus for distributed applications,
and provides highly tuned application-level multicast, group communication,
and point to point support. Spread services range from reliable messaging
to fully ordered messages with virtual synchrony delivery guarantees, even in case
of computer failures and network partitions.

We should check whether these changes impose any problems and update our packages / plugins accordingly. This could also pose an opportunity to introduce plugins to the Java library.