* 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.
* 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
* Update docu and logging
* Extracted and updated constants from `worker_desc` into separate file
* Update and re-calibrate communication error handling
* Allow simplified pivot negotiation
why:
This feature allows to turn off pivot negotiation so that peers agree
on a a pivot header.
For snap sync with fast changing pivots this only throttles the sync
process. The finally downloaded DB snapshot is typically a merged
version of different pivot states augmented by a healing process.
* Re-model worker queues for accounts download & healing
why:
Currently there is only one data fetch per download or healing task.
This task is then repeated by the scheduler after a short time. In
many cases, this short time seems enough for some peers to decide to
terminate connection.
* Update main task batch `runMulti()`
details:
The function `runMulti()` is activated in quasi-parallel mode by the
scheduler. This function calls the download, healing and fast-sync
functions.
While in debug mode, after each set of jobs run by this function the
database is analysed (by the `snapdb_check` module) and the result
printed.