Am 28.02.2012 um 19:15 schrieb Yanni Chiu: > On 28/02/12 11:03 AM, Norbert Hartl wrote: >> >> I first used image persistence but the image grow to large. Then I added >> fuel as journal to be written before image save in order to be able to >> recover from an emergency. >> Now we redo the persistence part. An account object graph is dissected >> into configuration part and payload part. The payload is written >> directly to mongo db in a Json format. The configuration part will be >> written as fuel blob to mongo. Planned is that at startup a configured >> amount of account fuel blobs are loaded and started. Those >> configurations have their own proces ses that write back payload to >> mongo. Etc. > > That's similar to what I do, except no image save and no mongo db. > As soon as the fuel blobs are in mongo (or on disk) no image save is needed then and I will start fresh everytime which is more reliable. Mongo is quite nice because I have a few hundred megabytes of data. And via cron it runs a map/reduce task to create the statistics about the data that has been fetched. The statistical data is displayed in charts on the web site again.
Norbert > Here's how it goes: > - on restart the image reconstructs a Pier kernel saved via Fuel to a file > - included in the Pier kernel is what you're calling the "configuration part" > - there are custom (non-std Pier) components here. > - the components in the reconstructed image can read/write a "payload" part, > which is serialized to files using Fuel and SandstoneDb. > - additionally, a "sub-tree" of the Pier kernel can be exported to a file > using Fuel serialization, and later imported using Fuel deserialization. > > No URL available at the moment. > > Aside - before Fuel/SandstoneDb, I was using Glorp/PostgreSQL. I've gained a > lot of simplicity, but lost sequence numbers and object caching (and maybe > more things, that have not been a problem so far). I've written a seqno > replacement, but the lack of object caching is not a problem at the moment > (i.e. small data sets, so far). > >
