Posted by Coder.
Feb
27
Posted by Coder.
Embedded.com – Using design patterns to identify and partition RTOS tasks: Part 1
… any operation whose deadline is measured in milliseconds—not microseconds—is a candidate for a high priority task. Assuming that your system has some serious computing to do at least once in a while, then anything that your system must do in milliseconds will miss its deadline if it has to wait for the serious computing to complete. (If your system never has any time-consuming CPU activity, then you’re …
Feb
21
Posted by coder.
ACM Queue – High-Performance Team – Does your development team have a high-performance mind-set?
If you want to keep producing high-performance software, you must be able to run reproducible, comparable performance tests. Ideally, you’ll have dedicated, standard hardware on which to run these tests; this should be representative of, if not directly comparable with, what your customers run in production. You’ll run a basic set of performance tests as part of your release cycle, plus more comprehensive benchmarks as required.So what …
Feb
21
Posted by coder.
ACM Queue – High-Performance Team – Does your development team have a high-performance mind-set?
Designing for performance is a controversial area; there are those who think you must always start by designing for performance, and others who think you should start with something that works and optimize it later. Both approaches have their merits; as always, it’s a case of finding the right balance between the two.
High-level design decisions are often hard to change, and thus are fundamentally tough to optimize. …
Feb
21
Posted by coder.
ACM Queue – A Conversation with Jarod Jenson – Tales from the trenches with a former Enron performance guru
Chances are your algorithm is good, so you should do some hunting elsewhere. Use the tools you have today, such as DTrace or VTune. Ask where the application is spending its time. If it is in the code, you’re back to where you started, but I would be willing to bet if you’re having massive performance problems, it’s not directly in your …
Feb
10
Posted by coder.
Sun Dialogue Programs
(Q): If you have to pick top 10 things that you must monitor on any server to look for performance and/or scalability issues…what would they be?
Richard McDougall (A): Off the top of my head, in no particular order:
CPU: Check idle time and run queue length.
If there’s a CPU bottleneck, check if it’s an application or kernel CPU utilization issue with mpstat: high percentages of users indicate it’s an application issue. High sys may point to high network load …
Jan
27
Posted by coder.
Allies pledge $10 billion to boost Itanium | CNET News.com
Intel, Hewlett-Packard and seven other server companies (Unisys, Silicon Graphics Inc., NEC, Hitachi, Fujitsu, Fujitsu-Siemens and Groupe Bull.) will spend $10 billion through 2010 to try to increase adoption of the Itanium processor.
And the kicker…
“Itanium has been taking share from both IBM power and Sun Sparc. We’re on the right trajectory, but we want to go faster,” Tom Kilroy, general manager of Intel’s Digital Enterprise Group, said at a press event …
Jan
26
Posted by coder.
Performance Information and Tools
My observation is that utilization is useless as a metric and should be abandoned. It has been useless in virtualized disk subsystems for some time, and is now useless for CPU measurement as well. There used to be a clear relationship between response time and utilization, but systems are now so complex that those relationships no longer hold. Instead, you need to directly measure response time and relate it to throughput. Utilization is properly defined …
Jan
23
Posted by coder.
developerWorks : Blogs : Grady Booch
Distributed two-phase commit will be avoided by recoverable messaging to applications (via services) that consult and modify the database and send a recoverable reply. Database size will become a non-issue. We’ll see lots of low-latency asynchronous replication of reference data among databases serving various applications and their associated service interfaces.
Jan
19
Posted by coder.
AskTom “”Not to do” Things”
don’t accept string literals from end users and concatenate them into your SQL (eg: DO use binds in almost all cases)
don’t test on an empty database or a database with a small percentage of the real system. Importing statistics from a “real” database doesn’t work. You need real data volumes if you want to see what will actually happen in real life.
don’t test with a single user, scalability issues will never make themselves apparent.
don’t say …
Jan
15
Posted by coder.
New features added to Servlet 2.5
Annotation performance
Whether or not you use annotations—and especially if you don’t—it’s important to understand the performance impact they can have on a server at startup. In order for the server to discover annotations on classes, it must load the classes, which means that at startup, a server will look through all the classes in WEB-INF/classes and WEB-INF/lib, looking for annotations. (Per the specification, servers don’t have to look outside these two places.) You can avoid …