Commit Graph

5 Commits

Author SHA1 Message Date
Jordan Hrycaj 7688148565
Snap sync can start on saved checkpoint (#1327)
* Stop negotiating pivot if peer repeatedly replies w/usesless answers

why:
  There is some fringe condition where a peer replies with legit but
  useless empty headers repetely. This goes on until somebody stops.
  We stop now.

* Rename `missingNodes` => `sickSubTries`

why:
  These (probably missing) nodes represent in reality fully or partially
  missing sub-tries. The top nodes may even exist, e.g. as a shallow
  sub-trie.

also:
  Keep track of account healing on/of by bool variable `accountsHealing`
  controlled in `pivot_helper.execSnapSyncAction()`

* Add `nimbus` option argument `snapCtx` for starting snap recovery (if any)

also:
+ Trigger the recovery (or similar) process from inside the global peer
  worker initialisation `worker.setup()` and not by the `snap.start()`
  function.
+ Have `runPool()` returned a `bool` code to indicate early stop to
  scheduler.

* Can import partial snap sync checkpoint at start

details:
 + Modified what is stored with the checkpoint in `snapdb_pivot.nim`
 + Will be loaded within `runDaemon()` if activated

* Forgot to import total coverage range

why:
  Only the top (or latest) pivot needs coverage but the total coverage
  is the list of all ranges for all pivots -- simply forgotten.
2022-11-25 14:56:42 +00:00
Jordan Hrycaj bba1bea4c8
Snap sync state save (#1302)
* Piecemeal trie inspection

details:
  Trie inspection will stop after maximum number of nodes visited.
  The inspection can be resumed using the returned state from the
  last session.

why:
  This feature allows for task switch between `piecemeal` sessions.

* Extract pivot helper code from `worker.nim` => `pivot_helper.nim`

* Accounts import will now return dangling paths from `proof` nodes

why:
  With proper bookkeeping, this can be used to start healing without
  analysing the the probably full trie.

* Update `unprocessed` account range handling

why:
  More generally, the API of a pairs of unprocessed intervals favours
  the first set and not before that is exhausted the second set comes
  into play.

  This was unfortunately implemented which caused the ranges to be
  unnecessarily fractioned. Now the number of range interval typically
  remains in the lower single digit numbers.

* Save sync state after end of downloading some accounts

details:
  restore/resume to be implemented later
2022-11-16 23:51:06 +00:00
Jordan Hrycaj e14fd4b96c
Prep for full sync after snap make 6 (#1291)
* Update log ticker, using time interval rather than ticker count

why:
  Counting and logging ticker occurrences is inherently imprecise. So
  time intervals are used.

* Use separate storage tables for snap sync data

* Left boundary proof update

why:
  Was not properly implemented, yet.

* Capture pivot in peer worker (aka buddy) tasks

why:
  The pivot environment is linked to the `buddy` descriptor. While
  there is a task switch, the pivot may change. So it is passed on as
  function argument `env` rather than retrieved from the buddy at
  the start of a sub-function.

* Split queues `fetchStorage` into `fetchStorageFull` and `fetchStoragePart`

* Remove obsolete account range returned from `GetAccountRange` message

why:
  Handler returned the wrong right value of the range. This range was
  for convenience, only.

* Prioritise storage slots if the queue becomes large

why:
  Currently, accounts processing is prioritised up until all accounts
  are downloaded. The new prioritisation has two thresholds for
  + start processing storage slots with a new worker
  + stop account processing and switch to storage processing

also:
  Provide api for `SnapTodoRanges` pair of range sets in `worker_desc.nim`

* Generalise left boundary proof for accounts or storage slots.

why:
  Detailed explanation how this works is documented with
  `snapdb_accounts.importAccounts()`.

  Instead of enforcing a left boundary proof (which is still the default),
  the importer functions return a list of `holes` (aka node paths) found in
  the argument ranges of leaf nodes. This in turn is used by the book
   keeping software for data download.

* Forgot to pass on variable in function wrapper

also:
  + Start healing not before 99% accounts covered (previously 95%)
  + Logging updated/prettified
2022-11-08 18:56:04 +00:00
Jordan Hrycaj d53eacb854
Prep for full sync after snap (#1253)
* Split fetch accounts into sub-modules

details:
  There will be separated modules for accounts snapshot, storage snapshot,
  and healing for either.

* Allow to rebase pivot before negotiated header

why:
  Peers seem to have not too many snapshots available. By setting back the
  pivot block header slightly, the chances might be higher to find more
  peers to serve this pivot. Experiment on mainnet showed that setting back
  too much (tested with 1024), the chances to find matching snapshot peers
  seem to decrease.

* Add accounts healing

* Update variable/field naming in `worker_desc` for readability

* Handle leaf nodes in accounts healing

why:
  There is no need to fetch accounts when they had been added by the
  healing process. On the flip side, these accounts must be checked for
  storage data and the batch queue updated, accordingly.

* Reorganising accounts hash ranges batch queue

why:
  The aim is to formally cover as many accounts as possible for different
  pivot state root environments. Formerly, this was tried by starting the
  accounts batch queue at a random value for each pivot (and wrapping
  around.)

  Now, each pivot environment starts with an interval set mutually
  disjunct from any interval set retrieved with other pivot state roots.

also:
  Stop fishing for more pivots in `worker` if 100% download is reached

* Reorganise/update accounts healing

why:
  Error handling was wrong and the (math. complexity of) whole process
  could be better managed.

details:
  Much of the algorithm is now documented at the top of the file
  `heal_accounts.nim`
2022-10-08 18:20:50 +01:00
Jordan Hrycaj eca5882238
Isolating sync action modules (#1249)
* Miscellaneous updates TBC

* Disentangled pivot2 module from snap

why:
  Wrote as template on top of sync so it can be shared by fast and snap
  sync.

* Renamed and relocated pivot sources

* Integrated `best_pivot` module into full and snap sync

why:
  Full sync used an older version of `best_pivot`

* isolating download module from full sync

why;
  might be shared with snap sync at a later stage
2022-09-30 09:22:14 +01:00