Zing - A JVM for virtualized x86 platforms with pauseless GC

http://www.azulsystems.com/products/zing/

by cgbystrom • 16 years ago

59 25 16 years ago

Azul is a great innovator in the JVM space, and I think their innovation will start to trickle down to other VM based languages like Ruby, Python, PHP, JavaScript etc. They've already open sourced some of their innovations: http://www.managedruntime.org

nwmcsween• 16 years ago

Not so much in vms and more in beating current operating systems into actually working for the applications. I think a few other language vms had the same issue but instead of trying to beat Linux into usability they used bare hardware via qemu.

wccrawford• 16 years ago

I really, really hate sales sites that don't list prices.

I also think their use cases are either a joke or written by a fool. "Scary for Apps"? Seriously? http://www.azulsystems.com/products/zing/use-cases Also makes a lot of bold statements that it doesn't even try to back up with numbers like "Better application performance under hypervisors than if run natively".

My scam sense tells me to run for the hills just from that one page. I hope for their sake that they redo that page in a hurry.

Nrsolis6• 16 years ago

You probably don't buy much equipment.

Keep this in mind: most companies that sell to enterprise and service provider customers aren't looking to make money with their website. Their SALESPEOPLE are there to properly qualify the leads and demonstrate the value of the product.

The whole point of not listing prices is to get customers to self-qualify. Those that genuinely find value in the products as presented will make the effort to contact the company. Price is really only something that is mentioned towards the end of the sale and indicates that there is considerable room for discounting from list price.

THAT's how it's done.

KC8ZKF3• 16 years ago

That's the path Sun Microsystems took in the earlier part of this century. The problem was, it was much easier to head over to Dell and buy a box and slap Linux on it. Ten minutes of your time, and you didn't have to try to convince a salesperson you were worthy of buying something.

nl• 16 years ago

Azul isn't a scam - based on past performance on other platforms I'd take their claims fairly seriously.

Having said that, prices would be nice to see.

jaen• 16 years ago

Previous discussion about the (awesome) GC: http://news.ycombinator.com/item?id=2022723

codexon• 16 years ago

I wonder when a real time GC will be available for openjdk.

jburwell• 16 years ago

This technology could be extremely interesting -- especially if they make it easy to provision on EC2. Getting rid of the overhead to customize OS distributions simply to run a JVM would reduce TCO and time to market not to mention better resource utilization.

spullara• 16 years ago

If anyone sees an AMI that boots on EC2 built from the sources at http://www.managedruntime.org/ please send it my way.

nitrogen• 16 years ago

Simply regarding the pauseless GC aspect, what is preventing someone from adding an existing realtime garbage collector like Rollendurchmesserzeitsammler (hereinafter rdmzs) to OpenJDK? Obviously rdmzs is designed for audio processing, as it bases its heap size on the audio processing cycle time, but are these similar GC concepts, or is the "pauseless GC" mentioned here something completely different from what rdmzs does?

jasonwatkinspdx2• 16 years ago

I'm not familiar with the internals of rdmzs, but there's a fair bit of actual technical information available about the Azul collector. It makes heavy use of manipulating virtual address mappings, and by this gains the property of being relatively insensitive to heap size.

My impression is that it's a copying collector that works on pages at a time. When a page is relocated, it's marked protected in the memory address mappings, allowing the runtime to trap and fix any stale pointers at the moment they are used. At the same time, the collector proper uses memory fences to keep track of what pointers have been fixed, eventually allowing the protected pages to be released from the memory map.

I don't know GC literature very well, but AFAIK this design is novell. The original implementation made heavy use of high performance memory primitives supplied by the Azul hardware. I gather they now have found a way of running with acceptable performance on commodity x86 processors under the virtualization.

pmjordan• 16 years ago

This sounds brilliant, virtual memory is a hardware feature which is currently sorely underused in user space. Unfortunately, most mainstream kernels don't give you deep enough access to the VM subsystem for serious trickery. For example, you can't map the same memory at multiple addresses unless it's file-backed; there's just no API for it. I have to admit I don't know if this would cause problems with caches on certain hardware.

In any case, you're free to mess with (virtualised) page tables when the parent is a hypervisor.

po• 16 years ago

I'm actually more interested in the "elastic memory" bit: http://www.azulsystems.com/products/zing/elastic-memory

When I used to work with JVM's all day I was always frustrated about having to decide how big a maximum heap for a given app would be. We had some xml processing tasks that almost never used much memory but every now and then would need tons. It was one part I couldn't thin-provision.

Am I right in interpreting this as shipping the JVM work off to a dedicated appliance-like server? Does that mean the memory profile on the appliance is the one that can be thin-provisioned?

Heap size tuning is one of those things that made me hate the JVM.

Zing - A JVM for virtualized x86 platforms with pauseless GC

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