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Showing posts from June, 2010

Performance

Ubuntu 9.10 ext4 copy disk->disk
~22-29MB/sec
~25MB/sec avg
~1.4GB/min
~10min to copy 14GB

Java DNS cache

Replace Java DNS with dnsjava

Prior to Java 6 DNS resolutions were cached forever.

Defaults: Java 6 DNS positive responses are cached for 30 seconds and negative responses for 10 seconds

-Dsun.net.inetaddr.ttl=3600


By default, when a security manager is installed, in order to protect against DNS spoofing attacks, the result of positive host name resolutions are cached forever. When a security manager is not installed, the default behavior is to cache entries for a finite (implementation dependent) period of time. The result of unsuccessful host name resolution is cached for a very short period of time (10 seconds) to improve performance.

HTML and CSS

Adobe Reader Install - Ubuntu

JBoss

Scan rate to detect changes, i.e., jsp

<JBOSS-INSTALL_DIR>\server\<server config>\conf\jboss-service.xml

<!-- Frequency in milliseconds to rescan the URLs for changes -->
<attribute name="ScanPeriod">5000

JNDI testing

Trillion node network

Trillions video
trillion node network
scalability - no central authorities (registration, namespaces, ontologies)
no device individual attention
tracktability size can't increase complexity
comprehensiveness

bit, byte, name/value

Internet of Things