Frequently Asked Questions
The Zing High Performance JVM
For Open Source Developers
- What is Zing?
- Zing is a 100% Java-compatible JVM based on Oracle HotSpot and optimized for Linux and x86. Designed for enterprise applications and workloads that require large memory, high transaction rates, consistent response times and high sustained throughput, Zing is the only JVM that delivers response times independent of heap size.
- How is Zing different from traditional JVMs for deploying Java applications?
Zing is a highly optimized JVM and elastic runtime that breaks traditional Java scale barriers and provides applications with orders of magnitude improvement in Java responsiveness, scale and throughput. The Zing JVM distribution includes a non-intrusive, production-time application visibility tool, called Zing Vision (ZVision). With ZVision IT organizations have for the first time a zero-overhead, fine-grained visibility tool that can help find problems and accelerate resolution of elusive production issues.
- Why is Zing important to Java developers, architects and application owners?
With Zing 5.0 Azul has created the most scalable Java Virtual Machine (JVM) for enterprise workloads and made it available on cost-efficient commodity hardware. With Zing 5.0 enterprises can now dramatically simplify Java deployments by using fewer instances while achieving greater response time consistency under load and dramatically lowering operating costs.
- Isn’t Zing just another JVM?
No. At its core, Zing uses the Azul C4 (Continuously Concurrent Compacting Collector) which eliminates "stop-the-world" pauses that limit the scalability of all traditional JVMs. Because a single instance can scale beyond a few Gigabytes to more than a 1/2 Terabyte of memory, Zing can dramatically reduce the total number of instances needed to support enterprise applications or multi-tenancy SaaS/PaaS solutions, simplifying deployments, dramatically improving response time consistency and lowering operational costs.
- How does Zing deliver better performance than other JVMs?
Zing eliminates "stop-the-world" garbage collection pauses that limit the scalability of other JVMs so that each Zing JVM instance can scale to over 300 GB of heap memory. In addition, Zing utilizes highly optimized client and server compilers and uses tiered compilation by default (e.g. C1 + C2).
- Will Zing work on my desktop machine/mobile device?
Zing is designed for use on servers only.
- How can I try Zing?
Through our free managed trial program. You can see if your environment is supported by checking our specifications page.
- How can I buy Zing?
Contact us via email, phone (+1 650.230.6500) or web form.
- What is Zing Vision?
Zing Vision is a zero overhead, always-on production time monitoring, diagnostic and tuning tool instrumented into the Zing JVM. The Zing JVM is always collecting data as a side-effect of work it has to do anyway, which allows systems administrators to utilize this information through Zing Vision without fear of impacting running applications.
- Is Zing Java certified?
Yes, Zing is a fully Java-compliant JVM. As an Oracle Sun Community Source Code Licensee (SCSL), Azul derives Zing from the same source base as Oracle HotSpot and certifies Zing with the identical Java 6 Technology Compatibility Kit (TCK). Hence, every version of the Zing JVM is 100% Java Compatible.
- Do I need to port my application to Zing?
No. Deploying Zing requires no changes to existing applications. You merely point the application’s JAVA_HOME environmental variable to the Zing JDK and you are running on the most scalable JVM on the market. Zing also requires no changes to other aspects of your infrastructure – security, other applications, monitoring tools, etc.
- What are the major improvements in the latest release (Zing 5.2)?
Zing 5.2 is optimized for the Linux OS on x86 servers and adds the option to deploy without a hypervisor (i.e. standalone, native JVM deployment). In this version Azul has also added support for more Linux distros, including RHEL 5/6, CentOS 5/6, Ubuntu 10.04 LTS, Ubuntu 12.04 LTS and SUSE SLES 11 sp1 and sp2. Additional distros will be certified this year. Zing 5.2 also has a number of performance improvements. You can read more in the press release here.
- How does the Zing JVM support large heap sizes and how is it elastic?
Zing allows Java applications to utilize any amount of memory they need to execute, limited only by the physical memory in a system or the amount recognizable by the hypervisor. Because of Zing’s unique garbage collector, based on Azul’s groundbreaking C4 (Continuously Concurrent Compacting Collector) technology, GC pauses are independent of size of the JVM heap and do not limit application scalability. In addition, Zing includes a patented innovation of “memory pools” (i.e. memory reserves) that allows Zing JVMs to dynamically grow its memory footprint based on real-time demand; when demand lessens, Zing gives this memory back to the system. This memory reserve not only ensure consistent performance under heavy load, but it can act as emergency memory for JVMs that encounter “memory leaks” due to bugs or coding errors.
- What versions of the JDK does Zing support?
Zing supports any Java SE/EE 6 and most J2SE 5.0 applications.
- How is the Zing JVM invoked by an application?
Once a Zing LX JVM is installed on a system, invoking it is done just like any other JVM/JDK (i.e. by simply changing JAVA_HOME to point to the Zing JDK).
- Which operating systems and versions are supported?
x86: Linux (RedHat 5.4 or later, CentOS 5/6, SUSE SLES 11 sp1 and sp2, Ubuntu 10.04 LTS and 12.04 LTS)
- How does the Zing JVM deliver pauseless operation?
The Zing JVM uses the Azul C4 garbage collector by default. The C4 collector is continuously compacting regardless of heap size and never uses 'stop-the-world' pauses for garbage collection.
- What is the C4 garbage collector?
The C4 (Continuously Concurrent Compacting Collector) is an updated generational form of the Azul Pauseless GC Algorithm and is the default collector of the Zing JVM.
- Can Zing help resolve database contention?
Yes. With fewer application instances, your database will see fewer connections and less contention.
- Has Zing been tested with a wide variety of Java applications?
Yes. Azul is a SCSL/OCSL (Sun/Oracle Source Code Licensee) which includes access to tens of thousands of tests which ensure ongoing Java compatibility. In addition to these tests, for each release we test a variety of application stacks (including WebLogic, WebSphere Application Server, JBoss and Tomcat), open source software and 3rd party apps. Please contact us if you have a question about a particular application.
- How much does Zing cost?
Pricing is based on an annual subscription per server.
- Why should business owners care about Zing?
Java applications are often business-critical and mission-critical. Performance and scalability issues that affect revenue and usage are often NOT due to the application, database or network but are more often related to the choice of JVM. By choosing the Zing JVM, you can eliminate unexpectedly long wait times for users and out-of-memory crashes to capture lost revenue and customers and deliver a consistent user experience even under heavy loads.
- My application has to deliver a strict SLA. How can Zing help?
Zing eliminates long response time delays, inconsistent response times (aka response time outliers) and system crashes that can cause SLA violations.
- How can Zing help my Cloud-based or SaaS-based application?
Because of memory and scalability limitations, conventional JVMs are not a good fit for cloud- and SaaS-based services. Zing is the best JVM for multitenant SaaS and cloud applications. Zing allows more tenants to be run on a single instance, scales elastically as loads increase to prevent one tenant's peak from affecting another tenant's response times, and lets you deploy large customers without worrying about scalability.
- We're a software company. Why should I encourage my customers to deploy on Zing?
Your Java-based application will run better - more scalable and more consistent - on Zing than any other JVM. Zing also makes deployments simpler, with fewer instances and less tuning; allows your customers more flexibility in deployment type, such as enterprise clouds or virtualized systems; and provides always-on monitoring tools to optimize performance on production (running) systems.
- How can Zing save me money on database licenses?
Zing allows you to deploy fewer instances for the same number of users, so you can also have fewer database servers.
For Open Source Developers
- How is Zing different from traditional JVMs for deploying open source applications?
Zing is optimized for Linux and x86 hardware favored by users of open source. Zing improves the performance of your open source applications with orders of magnitude improvement in Java responsiveness, scale and throughput. The Zing JVM distribution also includes a non-intrusive, production-time application visibility tool called Zing Vision (ZVision). With ZVision you can debug development issues quickly, and your users have for the first time a zero-overhead, fine-grained visibility tool that can help find problems and accelerate resolution of elusive production issues.
- Why is Zing important to open source developers?
With Zing open source developers can now take advantage of very large memory heaps and achieve greater response time consistency under load.
- How can I use Zing in my open source development project?
Through our free open source developer access program. Email us at email@example.com to request access. You can see if your environment is supported by checking our specifications page.
- How can users of my open source project buy Zing?
Please refer your users to Azul Systems. They can contact us via email, phone (+1 650.230.6500) or web form. Please feel free to post this information on your web site.
- What license do I need for open source development, qualification and testing?
You will need the Azul open source development license. When you download the Zing JVM, you will accept this license as part of the process.
- What license will users of my project need for deployment?
Users of your open source project will need to purchase a production license and maintenance from Azul Systems. Licenses are based on an annual subscription per server. Please direct your users to call us at +1.650.230.6500, email us at firstname.lastname@example.org or use our web form to request licensing assistance.
- Is the Zing JVM open source?
Zing is not open source.
- How can I get support during development?
Free support is available on the developer forum here. You may also purchase a developer support contract from Azul Systems. Please contact us for more information.
- Can I embed Zing in my open source project or in software that I sell?
You may include Zing with your open source project or commercial software. Your users or buyers will need a production license in order to deploy the software on the Zing JVM.
1J2SE 5.0 applications that use functionality not explicitly removed in Java SE 6. For more information, please see our specifications page.