This is in response to community feedback that our existing reputation
calculation is too likely to disqualify storage nodes unfairly with
extreme swings up and down.
For details and analysis, please see the data_loss_vs_dq_chance_sim.py
tool, the "tuning reputation further.ipynb" Jupyter notebook in the
storj/datascience repository, and the discussion at
https://forum.storj.io/t/tuning-audit-scoring/14084
In brief: changing the lambda and initial-alpha parameters in this way
causes the swings in reputation to be smaller and less likely to put a
node past the disqualification threshold unfairly.
Note: this change will cause a one-time reset of all (non-disqualified)
node reputations, because the new initial alpha value of 1000 is
dramatically different, and the disqualification threshold is going to
be much higher.
Change-Id: Id6dc4ba8fde1be3db4255b72282207bab5491ca3
In an effort to distribute load on the reputation database, the
reputation write cache scheduled nodes to be written at a time offset by
the local nodeID. The idea was that no two repair workers would have the
same nodeID, so they would not tend to write to the same row at the same
time.
Instead, since all satellite processes share the same satellite ID
(duh), this caused _all_ workers to try and write to the same row at the
same time _always_. This was not ideal.
This change uses a random number instead of the satellite ID. The random
number is sourced from the number of nanoseconds since the Unix epoch.
As long as workers are not started at the exact same nanosecond, they
ought to get well-distributed offsets.
Change-Id: I149bdaa6ca1ee6043cfedcf1489dd9d3e3c7a163
The ApplyUpdates() method on the reputation.DB interface acts like the
similar Update() method, but can allow for applying the changes from
multiple audit events, instead of only one.
This will be necessary for the reputation write cache, which will batch
up changes to each node's reputation in order to flush them
periodically.
Refs: https://github.com/storj/storj/issues/4601
Change-Id: I44cc47767ea2d9423166bb8fed080c8a11182041
This has been a cause of some confusion, even though the fields are
labeled as being copies of config values.
Having them be under a field explicitly named "Config" makes this
clearer, plus, allows the values to be passed in simply as a copy
of the Config struct from the satellite, rather than copying the fields
individually (which can be error-prone, particularly as the AuditCount
field in UpdateRequest is apparently not the same thing as the
AuditCount field in reputation.Config).
Refs: https://github.com/storj/storj/issues/4601
Change-Id: I386953347b71068596618616934aa28e3245cdc1
We added nodes.disqualification_reason recently, but we didn't add a
corresponding column in the reputations table (despite having a
corresponding `disqualified` column there).
Without this change, the (very useful and informative) assignments to
updateFields.DisqualificationReason in reputations.go have no effect.
Refs: https://github.com/storj/storj/issues/4601
Change-Id: I77404902ca64b56aed72f1de76b303fe82b76aab
Set disqualification reason when reputations stats are updated on DB.Update.
Added tests for DisqualifyNode and for disqualification cases which happens during Update.
Change-Id: I00130ab5d9722422805159ad2f183c205de60f7e
inconsistency
The original design had a flaw which can potentially cause discrepancy
for nodes reputation status between reputations table and nodes table.
In the event of a failure(network issue, db failure, satellite failure, etc.)
happens between update to reputations table and update to nodes table, data
can be out of sync.
This PR tries to fix above issue by passing through node's reputation from
the beginning of an audit/repair(this data is from nodes table) to the next
update in reputation service. If the updated reputation status from the service
is different from the existing node status, the service will try to update nodes
table. In the case of a failure, the service will be able to try update nodes
table again since it can see the discrepancy of the data. This will allow
both tables to be in-sync eventually.
Change-Id: Ic22130b4503a594b7177237b18f7e68305c2f122
package in audit
This PR implements reputation store and replace overlay in audit service
to use such store for storing node's audit stats.
In order to keep the changeset smaller, most of the changes in this PR is for copying audit logic in overlay to
reputation package. In a following PR, the duplicating code will be
removed from overlay.
Change-Id: I16c12494a0970f44c422b26cf603c1dc489e5bc1
