Wednesday, June 10, 2009 at 4:00AM I spend a blog entry discussing single partition and every partition transactions when using distributed KV systems and solutions for some common problems
Tuesday, March 17, 2009 at 11:08PM IBM WebSphere eXtreme Scale is IBMs in memory data grid product (IMDG). It can be used as a key-value store which partitions the keys (using a form of consistent hashing) over a set of servers such that each server is responsible for a subset of the keys. It automatically handles replication which can be either synchronous of asynchronous and handles advanced placement so that replicas can be placed in different physical zones when compared to the placement of the primary. Think buildings, racks, floor, data centers. It is fully elastic in that servers can be added and removed and it automatically redistributes the partition primaries and backups. It can be scaled from one server to hundreds if not thousands of JVMs in a single grid. Each additional server provides more CPU, memory capacity and network and it scales linearly with grid growth. It also has a key-graph mode where a graph of objects can be associated with a single key and it allows fine grained modification of that graph. The object graph and key is stored in tuple form in this mode. This allows clients using different object representations of some subset of the IMDG schema to share data stored in the IMDG. It comes with automatic integration with databases so that values are automatically pulled from a database if not present and are written to the database when they change. Write behind logic allows writes to the database to be much more efficient and allows the grid to run with the database down. It comes with a HTTP Session filter to provide HTTP Session management for servlet containers. It have a flexible deployment model allowing a lot of customization by customers. We do a weekly video podcast on iTunes (search for extreme scale in iTunes) and make it available on YouTube also for customer education. We answer customer questions and forum topics from the week in a casual two person chat forum.
Wednesday, March 11, 2009 at 2:10AM I try to group XTP in to two main groups, type 1 and 2 and then subdivide type 2 in to 2a and 2b. I describe how I do this grouping and then amplify it a little in the context of cloud services.
