This is my personal blog. The views expressed on these pages are mine alone and not those of my employer.

Friday, September 26, 2003

Wow, this is damn cool: Hamsam is a multi-protocol instant messaging API, developed in Java, that helps in development of instant messaging applications.

High Availability, Scalable Storage, Dynamic Peer Networks: Pick Two: "Abstract
Peer-to-peer storage aims to build large-scale, reliable
and available storage from many small-scale unreliable,
low-availability distributed hosts. Data redundancy
is the key to any data guarantees. However, preserving
redundancy in the face of highly dynamic membership
is costly. We use a simple resource usage model to measured
behavior from the Gnutella file-sharing network to
argue that large-scale cooperative storage is limited by
likely dynamics and cross-system bandwidth ónot by
local disk space. We examine some bandwidth optimization
strategies like delayed response to failures, admission
control, and load-shifting and find that they do not
alter the basic problem. We conclude that when redundancy,
data scale, and dynamics are all high, the needed
cross-system bandwidth is unreasonable."

Querying the Internet with PIER: "The database research community prides itself on
scalable technologies. Yet database systems traditionally
do not excel on one important scalability dimension:
the degree of distribution. This limitation
has hampered the impact of database technologies
on massively distributed systems like the Internet.
In this paper, we present the initial design of
PIER, a massively distributed query engine based
on overlay networks, which is intended to bring
database query processing facilities to new, widely
distributed environments. We motivate the need for
massively distributed queries, and argue for a relaxation
of certain traditional database research goals
in the pursuit of scalability and widespread adoption.
We present simulation results showing PIER
gracefully running relational queries across thousands
of machines, and show results from the same
software base in actual deployment on a large experimental

Robust and Efficient Data Management for a Distributed Hash Table: "This thesis presents a new design and implementation of the DHash distributed hash table
based on erasure encoding. This design is both more robust and more efficient than the
previous replication-based implementation.
DHash uses erasure coding to store each block as a set of fragments. Erasure coding in-
creases availability while saving storage and communication costs compared to a replication
based design. DHash combines Chord's synthetic coordinates with the the set of fragments
to implement server selection on block retrieval.
DHash enhances robustness by implementing efficient fragment maintenance protocols.
These protocols restore missing or misplaced fragments caused by hosts joining and leaving
the system.
Experiments with a 270-node DHash system running on the PlanetLab and RON
testbeds show that the changes to DHash increase the rate at which the system can fetch
data by a factor of six, and decrease the latency of a single fetch by more than a factor of two.
The maintenance protocols ensure that DHash is robust without penalizing performance.
Even up to large database size, the per host memory footprint is less than 10 MB and the
per host network bandwidth is under 2 KB/sec over a wide range of system half-lives."

Hard lessons learned about Technology Evangelism: "Now that I am much older I can see that I have been able to achieve more by taking a less principled stance. That the most important part of talking about technology is actually listening. And that it is only technology, that it is only one of a set of tools to solve someone's problems. That is important to see context, and that you have to realize it is not about you, but all about solving the problem. Any professional evangelist should have some mandatory psychotherapy before he starts his job."

Guardian Unlimited | Special reports | Colombia kidnap victim reunited with family: "Mr Scott was marched along a mountainous jungle track with seven other frightened hostages before making his escape the day after being captured. He leapt from a high ravine and plunged into a swollen river before stumbling across some indigenous people after 12 days alone in the jungle."

Talking Points Memo: "For quite some time this White House has functioned like a heavily leveraged business, an overextended investor that suddenly gets a margin call. To extend the business metaphor, the White House has been surviving not on profits but expectations of future profits or, in other words, credibility. The White House has been able to get the public to sit tight with a lot of objectively poor news (a poor economy, big deficits, bad news from abroad) on the basis of trust. But a combination of the manifest incompetence of the planning for post-war Iraq and the dishonesty of the build-up for the war have become increasingly difficult to defend or deny. And that's struck a grave blow against the president's credibility."

Framing a Democratic Agenda: "Interestingly, the wealthy benefit disproportionately from the American infrastructure. The Securities and Exchange Commission creates honest stock markets. Most of the judicial system is used for corporate law. Drugs developed with National Institutes of Health funding can be patented for private profit. Chemical companies hire scientists trained under National Science Foundation grants. Airlines hire pilots trained by the Air Force. The beef industry grazes its cattle cheaply on public lands. The more wealth you accumulate using what the dues payers have provided, the greater the debt you owe to those who have made your wealth possible. That is the logic of progressive taxation."

Unleashing Your Erotic Intelligence: "It is not that romance fades over time. It becomes riskier."

For a future release of P2P Sockets, I've thought about giving every "site" a "search" interface, which would really be a way to access the rendezvous peers for that peer group. Programmers would then simply feel like they are calling the search CGI-BIN for a site when in fact they are calling the rendezvous peers. This search interface could either be exposed as a standard part of the URL, such as ""
or it could be exposed as a standard port number that you post the information to. What could be returned would simply be a multi-part document of Jxta advertisements, which is simple, but it does expose some Jxta stuff. That's not necessarily bad if it solves the problem.

One thing I'm concerned about, however, is that I want to have some concrete "problems" that are trying to be solved before I start creating ungrounded mechanisms.

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