let's see if i got this... On 06 17, 07, at 3:28 PM, Orlando Andico wrote: > coherence can be compared most directly to Terracotta. > > however Terracotta only provides 2-way clustering, and the second node > must be a standby. coherence provides a single-image shared memory for > multiple java applications across a grid; and all grid nodes are fully > active (can read/write to the shared memory) and replicated. so losing > a node is not fatal (all data on a node is replicated on AT LEAST one > other node). > > adding new nodes means some backups get copied to that new node to > distribute the load more effectively. losing nodes means the data on > that node is shifted to the backup node, while backups on that node > are re-copied to one of the surviving nodes. > > with a 1000-node cluster, coherence can do ~25M aggregations per > second (that's 25M puts into the shared store). of course reads are > much, much faster, and a general workload would have an app reading > stuff from the store, crunching on it for a long-ish time, and then > doing a put back into the store once done. >
Johnny-Johnny's favoriteApp is running on the grid. TheGrid using Terracotta is like a cluster file system is to memory. favoriteApp does a read of a file from Lala's workstation which is in Singapore... favoriteApp needs X amount of memory. TheGrid provides the memory. it doesn't need to say X memory is in sf... though physically the said address is located in Sara's Uber-Workstation in San Francisco at the Company's WestCoast base (since all other memory is currently occupied). and the TheGrid "hides" these facts to johnny- johnny's favoriteApp and terracotta handles the local caches and such... did i understand it correctly? ------------ Cocoy Dayao [EMAIL PROTECTED] big mango - http://arkangel1a.blogspot.com "People who are really serious about software should make their own hardware." --Alan Kay _________________________________________________ Philippine Linux Users' Group (PLUG) Mailing List [email protected] (#PLUG @ irc.free.net.ph) Read the Guidelines: http://linux.org.ph/lists Searchable Archives: http://archives.free.net.ph
