id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	launchpad_bug
661	Dynamic share migration to maintain file health	mmore		"Dynamic share repair to maintain file health. based on the following features
already exist in Allmydata-Tahoe1.3 we can improve automatic repair:

 1. Foolscap provides the knowledge of the alive nodes.

 2. Verification of file availability can be delegated to other node through
    read-cap or a verify-cap without security risk.

The proposed auto repair process:

 1. Using memory-based algorithm, because client know where the file shares
    exist so we can keep tack of alive file shares, for simplicity we
    consider that share availability from its node availability.

 2. repair process triggered automatically from the repairer, repair
    responsibility has many technique based repair cost ; network bandwidth
    and fault tolerant.

 3. time out , we can use lazy repair technique to avoid node temporary node
    failure, i.e waiting for a certain time before repair process starts.

 4. reintegration, using memory-based repair technique remembering failed
    storage servers, who come back to life, will help in reducing Tahoe grid
    resources such as network bandwidth and storage space.

 5. repairer, selection of repair responsibly takes many issues into
    consideration: security , repairer location , repairer resources.
"	enhancement	closed	major	undecided	code-encoding	1.3.0	duplicate	repair preservation availability