Open Heartbeat / News: Recent posts

Open Heartbeat now includes a feed handler for the popular Yahoo real time stock quote web service. Any number of instruments and fields can be selected from the library of instruments available on Yahoo's financial web site. The data collected is converted to the internal format used by Open Heartbeat and distributed throughout the Open Heartbeat network (Note - the use of Yahoo stock quotes is governed by the terms and conditions published on Yahoo's financial web site.

Nothing earth shattering, but my little test setup using two old laptops busy simulating and sharing updates as fast as there little CPUs can manage has just passed the billion message mark with zero errors, which makes me quite proud. Now these little guys have been plugging away at 250 or so messages per second for over 46 days in a row (and serving up my personal web pages etc at the same time). I'm publishing a screen shot of the admin web page on the openheartbeat home page to prove it.
I had a previous long-running test interrupted after a few weeks by one of those rare power outages in Los Angeles. This is running on Linux though - it's hard to imagine doing this under windows. I've never seen a socket connection last uninterrupted for more than a few days - nor run for more than a week or two before some auto-loaded system updates forces a reboot. I should note that there have been several such automatic patches on my servers over this period - but under Linux, this never forces a system reboot (unless the kernel itself is upgraded) and (as shown here) doesn't even break working socket connections.

I've just released a new version (for linux - windows will have to wait a few days) with some tiny changes to the demo gui piece. Nothing else changed.
The changes include a running message-per-second display in the title bar, and modifying the sample configuration file to select the built-in simulator mode which makes it a hundred times easier for a newbie to see it in action. Try it out. I've set the internal delays for around 1000 message-per-second on my old Bell workstation, which keeps the CPU pretty busy though still perfectly responsive (streaming movies at the same time is a bit of a challenge). It would be nice to see what a fast machine could support. 10,000/sec should be doable.

So far, everything happens in the dark - you can connect via telnet etc and query the built-in web server to get an idea of how it all works, but to really see something happen - we needed a GUI. More than that, we needed a GUI fast enough to keep up, and at 1000 or more updates a second, that's no mean feat. This version includes a super-fast X11 based gui that can handle 10 to 20 thousand updates per second on a low end Intel PC - and show every one on the screen. Now that's low latency.
And since the GUI is built on the same library as the daemon, it also has it's own mini web server for admin etc, and can run with or without a local daemon. I have a Windows based GUI client in the works too - almost as fast as this one. I just need to do a bit more polishing before releasing it.

I have been testing this during development with a simple price quote simulator running as a separate program. I was thinking about releasing this piece as a separate binary/source combo but instead decided to build the simulation capability in - using conditional compilation so that a stripped down version can be built if desired. Actually, it adds only a couple of K to the binary so there is little incentive to strip it out.... read more

I made a slight change to the web admin piece, using Ajax for the real time status updates instead of a 1 second refresh meta-tag. New source and windows + Linux binaries posted

The second significant release now features an identical feature set running on Windows as a service.
The code base is a bit different as a result - in fact, I changed the tree to be based on ohb (for Open Heartbeat) rather than the tentative tpd (Ticker Price Daemon). The tpd branch is now officially dead.

There are three versions available - Binary install sets for both Windows and Linux and the source code version. The source code version works as a standard Linux redistributable (./configure, make and make install) an also contains a VisualStudio10 solution.
All versions work seamlessly together.

I made the first code drop - actually 4 drops, each adding on a little bit or fixing some nasty little autotools related problems. This code drop is for Linux only this time, providing the core daemon functionality to collect, cache, compress and redistribute ticker quotes etc.
The basic functionality is there, though I still need to work on the auto-reconnect functionality. This version installs as a background daemon, managed through /etc/init.d/tpd start/stop etc. it also has a simple auto-refreshing web interface showing status and latest data snapshots on demand.... read more