Cloudburst is a compressing, log-structured virtual disk implemented in flash memory under the Linux operating system. Existing Linux filesystems (preferably with certain modifications) can run on top of Cloudburst. Unfortunately, more extensive filesystem modifications would be needed to make the results fully satisfactory than we had realized at first, and we did not complete them. Nevertheless, the Cloudburst design has some interesting aspects that may be of use to future efforts in flash file systems.
The Domain Name System (DNS) is a vital part of today's Internet, playing a role in vast numbers of web transfers each day. As the number of users and the number of names in the Internet grows exponentially, the DNS's ability to deliver name translations quickly becomes more and more integral to the performance of the web. This is a study of DNS latency. How long does the DNS take to return trans- lations? When it does take a long time, what went wrong? Do applications put DNS lookups in the critical performance path, or is DNS latency unimportant to apparent application responsiveness? We have taken traces of all network traffic in and out of a large research community. We analyzed the DNS activity and its relationship to other traffic and found that DNS does its job remarkably well most of the time: latencies are generally quite low. In rare cases of high latency, we found that at least half the time, one or more remote servers were down or unreachable. Finally, we found that while the information received in many DNS transactions was used right away, the delay between lookup and first use was often very large.
Cloudburst is a compressing, log-structured virtual disk implemented in flash memory under the Linux operating system. Existing Linux filesystems (preferably with certain modifications) can run on top of Cloudburst. Unfortunately, more extensive filesystem modifications would be needed to make the results fully satisfactory than we had realized at first, and we did not complete them. Nevertheless, the Cloudburst design has some interesting aspects that may be of use to future efforts in flash file systems.
