Latest news

NEW: APRIL NEWSLETTER

• We list all the latest Java performance related news and articles
  • "software engineering has a cost model that mostly encourages us to build incomplete constructs, because it's relatively cheap to fix."
• All the latest Java performance tips extracted in concise form
  • "Where a deadlock is caused by reversing the ordering of acquiring locks from both a synchronized object and ReentrantLock read lock, the JVM does not (yet) detect this." & "Common load balancing algorithms (ignoring affinity) include: simple round-robin (each request goes to the next resource in a list); weighted round-robin (higher weighted resources get requests more frequently than lower weighted resources, resources of the same weight have requests distributed evenly); random distribution; utilisation-balanced (requests are sent to the resource which currently has the lowest utilisation)."

MARCH NEWSLETTER

• We list all the latest Java performance related news and articles
  • "Load tests and stress tests rarely check for request storms on startup or failover, because the standard testing paradigm is to ramp up load gradually since that tends to be the most common load increase. If you don't have the 'request storm on startup and failover' scenario in your load test performance suite - it's time to add it."
• All the latest Java performance tips extracted in concise form
  • "If application processing is slow but there doesn't seem to be an abnormally high CPU usage, look for blocked threads across several stack dumps. These are likely showing lock contention causing a bottleneck in an otherwise parallel application. The stack traces and lock information show exactly where the contention is occurring."

FEBRUARY NEWSLETTER

• We list all the latest Java performance related news and articles
  • "Java is continually pronounced dead by Cluebies - let's just hope none of these Cluebies provide investment advice; with a track record that consistently wrong they would have recommended every disaster from Enron to Lehman as the next big winner to invest in!"
• All the latest Java performance tips extracted in concise form
  • "Percentiles (50th, 99th, 99.9th, 99.99th) are more accurate and informative than averages in the vast majority of distributed systems. Averages are normally only meanignfull for normal distribution statistics, and distributed systems tend to not show normal distribution for the statistics of most interest" and "Monitoring workflow consists of: collecting metrics; tracking them against a threshold; notifying if the threshold is breached; notifications are routed to the people that can handle them asap; providing dashboards (with drill down) that allow operators to see the status of (parts of) the system; providing trend visualization to allow identification and resolution of issues; and capacity analysis"

JANUARY NEWSLETTER

• We list all the latest Java performance related news and articles
  • "I've categorised the first batch of the 600 java performance tools we've listed over the last 12 years"
• All the latest Java performance tips extracted in concise form
  • "There is a difference between design optimization and code optimization - optimization is usually necessary at the design phase, and is not premature; not optimizing at the design phase can easily lead to bad architecture." and "Appropriate choices of data structures and algorithms are optimisations that are NOT premature."

Previous newsletters

All our previous newsletters can be viewed from here

How to use this site

This site has four main information resources:

• The uncategorized tips page lists many other web pages with Java performance tuning related information. Each web page has its performance tuning tips extracted and listed immediately after the URL is listed. These tips are being categorized, and the tips page links to those categories currently available. If the performance area you are interested in is not yet categorized, send us an email from this page telling us the categorization you'd like to see. In any of the tips pages, use your browser's "find" or "search" option to identify particular tips you are interested in on the page, and follow up by reading the referenced web page if necessary or desired.
• The resources page lists Java performance tuning resources including books, tools, reports, other performance tuning sites of interest, and Java performance tuning discussion groups.
• The news pages are monthly newsletters listing any new Java performance tuning related information, together with Kirk Pepperdine's discussion group roundup and Javva The Hutt.
• The tool reports pages are detailed introductory reports on various Java performance related tools, for both free and commercial tools.

This site has been designed to download almost as fast as possible. (Some stylistic markup and required server-side processing has been used in preference to absolute speed contraints.) The web tree contains very few graphics and almost no complex typesetting markup except for very simple tables, and the main pages can be accessed directly from the menu.

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