Posted by admin.
Oct
10
Posted by admin.
Hot off the press – October 2011!
http://www.amazon.com/Java-Performance-Charlie-Hunt/dp/0137142528
“The definitive master class in performance tuning Java applications…if you love all the gory details, this is the book for you.”
–James Gosling, creator of the Java Programming Language
Improvements in the Java platform and new multicore/multiprocessor hardware have made it possible to dramatically improve the performance and scalability of Java software.
Java™ Performance covers the latest Oracle and third-party tools for monitoring and measuring performance on a wide variety of hardware architectures and operating systems. The …
Aug
28
Posted by admin.
On GC Threads (via Hiroshi Yamauchi):
Since ParallelCMSThreads is computed based on the value of ParallelGCThreads, overriding ParallelGCThreads when using CMS affects ParallelCMSThreads and the CMS performance.
Knowing how the default values of the flags helps better tune both the parallel GC and the CMS GC. Since the Sun JVM engineers probably empirically determined the default values in certain environment, it may not necessarily be the best for your environment.
Aug
19
Posted by admin.
Watch out for false sharing; it’s an invisible scalability buster. The general case to watch out for is when you have two objects or fields that are frequently accessed (either read or written) by different threads, at least one of the threads is doing writes, and the objects are so close in memory that they’re on the same cache line.
Detecting the problem isn’t always easy. Typical CPU monitors completely mask memory waiting by counting it as busy time, which doesn’t …
Aug
19
Posted by admin.
http://static.googleusercontent.com/externalcontent/untrusteddlcp/research.google.com/en/us/people/jeff/stanford-295-talk.pdf
L1 cache reference 0.5 ns
Branch mispredict 5 ns
L2 cache reference …
Dec
27
Posted by admin.
What Your Computer Does While You Wait : Gustavo Duarte
Many discrete wait periods are required when accessing memory. The electrical protocol for access calls for delays after a memory row is selected, after a column is selected, before data can be read reliably, and so on. The use of capacitors calls for periodic refreshes of the data stored in memory lest some bits get corrupted, which adds further overhead. Certain consecutive memory accesses may happen more quickly but there are …
Jul
18
Posted by admin.
Hadoop Summit 2010 – Agenda
Hadoop is a powerful platform for data analysis and processing, but many struggle to understand how it fits in with regard to existing infrastructure and systems. A series of common integration points, technologies, and patterns are defined and illustrated in this presentation. [slides]
Apr
11
Posted by admin.
“As to why I left, it’s difficult to answer: just about anything I could say that would be accurate and honest would do more harm than good.”
He soldiered on till the end… then time came to turn off the lights and call it a night… Keep on truckin’, James!
Aug
2
Posted by admin.
Why can’t I see a transactional malloc()/free()? – Intel® Software Network
Intel STM Prototype v3.0 does provide transactional malloc() and free(). Any time malloc and free are used in __tm_atomic region or a function marked with tm_callable attribute they are replaced with a transactional safe malloc and free. For functions which are marked with tm_safe attribute, the compiler assumes user guarantees the safety of that function and does not replace the malloc and free. The user has …
Jul
4
Posted by admin.
FAQ
Will Oracle continue to invest in JRockit technology? Absolutely! JRockit is a strategic product for Oracle and its customers. Oracle will continue to invest in it significantly. Oracle will continue to pay attention to legacy-BEA and Oracle customers needs and customers should expect a strong roadmap for the JRockit JVM and all JRockit products.
Going forward, is JRockit going to be free or a for-charge product?Consistent with Oracle policies, JRockit Mission Control and JRockit Real Time, which include the JRockit JVM and …
May
25
Posted by admin.
Hueniverse: Scaling a Microblogging Service – Part I
The social web is creating demand for new scaling tools and
technologies. Current databases and caching solutions are simply unable
to handle a complex network of multiple relationship between objects.
While databases are still a good solution for persistent storage of
social data, each retrieval requires heavy calculation.