ClassifySegmentPieces uses custom set implementation instead map.
Side note, for custom set implementation I also checked int8 bit set but
it didn't give better performance so I used simpler implementation.
Benchmark results (compared against part 2 optimization change):
name old time/op new time/op delta
RemoteSegment/healthy_segment-8 21.7µs ± 8% 15.4µs ±16% -29.38% (p=0.008 n=5+5)
name old alloc/op new alloc/op delta
RemoteSegment/healthy_segment-8 7.41kB ± 0% 1.87kB ± 0% -74.83% (p=0.000 n=5+4)
name old allocs/op new allocs/op delta
RemoteSegment/healthy_segment-8 150 ± 0% 130 ± 0% -13.33% (p=0.008 n=5+5)
Change-Id: I21feca9ec6ac0a2558ac5ce8894451c54f69e52d
Currently, graceful exit is a complicated subsystem that keeps a queue
of all pieces expected to be on a node, and asks the node to transfer
those pieces to other nodes one by one. The complexity of the system
has, unfortunately, led to numerous bugs and unexpected behaviors.
We have decided to remove this entire subsystem and restructure graceful
exit as follows:
* Nodes will signal their intent to exit gracefully
* The satellite will not send any new pieces to gracefully exiting nodes
* Pieces on gracefully exiting nodes will be considered by the repair
subsystem as "retrievable but unhealthy". They will be repaired off of
the exiting node as needed.
* After one month (with an appropriately high online score), the node
will be considered exited, and held amounts for the node will be
released. The repair worker will continue to fetch pieces from the
node as long as the node stays online.
* If, at the end of the month, a node's online score is below a certain
threshold, its graceful exit will fail.
Refs: https://github.com/storj/storj/issues/6042
Change-Id: I52d4e07a4198e9cb2adf5e6cee2cb64d6f9f426b
The repair checker and repair worker both need to determine which pieces
are healthy, which are retrievable, and which should be replaced, but
they have been doing it in different ways in different code, which has
been the cause of bugs. The same term could have very similar but subtly
different meanings between the two, causing much confusion.
With this change, the piece- and node-classification logic is
consolidated into one place within the satellite/repair package, so that
both subsystems can use it. This ought to make decision-making code more
concise and more readable.
The consolidated classification logic has been expanded to create more
sets, so that the decision-making code does not need to do as much
precalculation. It should now be clearer in comments and code that a
piece can belong to multiple sets arbitrarily (except where the
definition of the sets makes this logically impossible), and what the
precise meaning of each set is. These sets include Missing, Suspended,
Clumped, OutOfPlacement, InExcludedCountry, ForcingRepair,
UnhealthyRetrievable, Unhealthy, Retrievable, and Healthy.
Some other side effects of this change:
* CreatePutRepairOrderLimits no longer needs to special-case excluded
countries; it can just create as many order limits as requested (by
way of len(newNodes)).
* The repair checker will now queue a segment for repair when there are
any pieces out of placement. The code calls this "forcing a repair".
* The checker.ReliabilityCache is now accessed by way of a GetNodes()
function similar to the one on the overlay. The classification methods
like MissingPieces(), OutOfPlacementPieces(), and
PiecesNodesLastNetsInOrder() are removed in favor of the
classification logic in satellite/repair/classification.go. This
means the reliability cache no longer needs access to the placement
rules or excluded countries list.
Change-Id: I105109fb94ee126952f07d747c6e11131164fadb
