November 15, 2005 - 21:00 UTC
Today we started the big master database merge. This step is simple in essence: we are combining all the scientific data from SETI@home classic and SETI@home/BOINC into one big database. However, this is the culmination of many months of effort.
What happened during those months? Among other things, we had to migrate all the data off of one server onto another, find and remove redundant data, add new fields to old records and populate them, write and test software to merge databases while keeping all relational constraints intact... Basically a lot of cleanup, a lot of testing, and backing up the entire set of databases between every major step.
While this merge is happening, nothing can be updating either of the master databases. We shut off the splitters (which input new workunits into the database) and the assimilators (which input new signals). Over the weekend we created a backlog of about 2 million results, so this should keep the clients well-fed for most of this outage. The assimilator queue, of course, will grow significantly. When everything but the signals themselves have been merged, we may turn the splitters back on (at this point they won't screw up any relational constraints by adding new work to the mix). When the merge is completely done, everything will be turned back on, and the assimilator queue should quickly drain.
Right now science being done in SETI@home classic is redundant to the science in SETI@home/BOINC, so this will be the last of the big science merges. The classic project will be shut down before the end of the year.
We do hope to eventually place the master science database on a faster machine with bigger/faster disks. This will mean another outage, but it will be a simple unload/reload of the data (as opposed to a unload/reload/correct/merge).
en résumé , ils commencent a fondre les données de seticlassic dnas seti/BOINC.
Plusieurs jours seront nécessaires et 2 000 000 d'unités ont été crées pour tenir pendant ces quelques jours.
Il s'agit de l'apothéose , de la manipulation finale de transfert de seticlassic à seti/BOINC.
Aprés cela , seticlassic n'aura plus aucun intéret car les résultat ne seront plus intégrés a leurs énormes bases de données. Tout le monde devra passer a BOINC.
Enfin seticlassic fermera définitivement avant la fin de l'année