bnewport's blog

Memory usage and sizing information for IBM WebSphere eXtreme Scale

This blog entry describes how WebSphere eXtreme Scale uses memory. This allows customers to better size how much memory they need when storing a large number of key value pairs in a grid.

 The text is in my personal blog at this link.

Memory or disk based XTP or maybe XDP!

Yesterday, I said the most important aspect of an XTP platform is the management. Automatic placing of data on a grid of computers, automatic scale out as new boxes are added and automatic replica count maintenance as boxes fail or are taken out of the grid.

Is XTP about memory based replication? No, and here is why.

I was explaining XTP in a meeting this morning and covered the usual aspects. It (in the form employed by ObjectGrid and its gigoherence competitors) uses replicated memory based storage for persistent state AND it uses a self healing/scaling grid to deploy that storage fabric on.

Characteristics of DataGrids

This is a great question. Depending on who you ask, you get a different answer. Vendors will pitch what they think and why competitors are wrong. I guess I just want to put out what I think it is so here goes.

Topology

Topology wise, there are three styles. The fixed number of partitions where records hash to one partition is the first.

Defering partition placement in a grid to avoid redistribution thrashing and other issues

We have scenarios where a customer may want to have say 200 partitions and preload the data into the grid when the partition primaries are initially placed. The customer might want to load 100Gb of data and planned on 500MB of primary data and 500MB of replica data per JVM.

Java versus PHP

We started building http://www.trackpedia.com at the beginning of January this year. We initially knocked it together using mediawiki and vbulletin. It was very easy to do this.

SDTimes comments on OSGI

Andrews article can be viewed here. It's a good introduction on OSGI and you can find another good introduction at this link on OSCAR at source forge.

I think OSGI has a big future on the server side.

J2EE alive and well in China

The 4th International Conference on Information Technology in Financial Services is organized annually by State Street and the Zhejiang University. It's my second time at the conference and once again, it's been a great experience. The sessions were lively and very interactive, thats my favorite kind of session.

WebSphere 5.1 XD goes GA.

We just shipped WebSphere 5.1 XD a couple of weeks ago. XD has many features that should appeal to customers.