This is a hopeful fix for extra memory usage since mempow activated, due to adding a lot of load to the garbage collector. It only applies to accounts verified from the import queue; the optimization hasn't been applied to block processing. But verifying online accounts when processing blocks is rare and generally would only last a short amount of time.
This allows testnets to more easily coexist on the same machines that are running a mainnet instance, and still tests the mempow computation and verification in a non-resource-intensive way.
We no longer need all the code complexity, now that 24 hours have passed since activation. We don't validate online accounts beyond 12 hours, and the data is trimmed after 24 hours.
- Added "singleNodeTestnet" setting, allowing for fast and consecutive block minting, and no requirement for a minimum number of peers.
- Added "recoveryModeTimeout" setting (previously hardcoded in Synchronizer).
- Updated testnets documentation to include new settings and a quick start guide.
- Added "generic" minting account that can be used in testnets (not functional on mainnet), to simplify the process for new devs.
We expect a "Couldn't build a to-be-minted block" log on every startup due to trying to mint before having any accounts. This one has moved from error to info level because error logs can be quite intrusive when using an IDE.
The BLOCK_SUMMARIES message type would differentiate between an empty response and a missing/invalid response. However, in V2, a response with empty summaries would throw a BufferUnderflowException and be treated by the caller as a null message.
This caused problems when trying to find a common block with peers that have diverged by more than 8 blocks. With V1 the caller would know to search back further (e.g. 16 blocks) but in V2 it was treated as "no response" and so the caller would give up instead of increasing the look-back threshold.
This fix will identify BLOCK_SUMMARIES_V2 messages with no content, and return an empty array of block summaries instead of a null message.
Should be enough to recover any stuck nodes, as long as they haven't diverged more than 240 blocks from the main chain.
This should hopefully fix a potential issue where peer's chain tip data becomes contaminated with other summary data, causing incorrect sync decisions.
The `start.sh` & `stop.sh` scripts have already been marked as executables in the source folder... But since we have only piped their contents, we need to set correct file permissions again.
This allows the first pass to always be served from the peer's cache of 8 summaries. This allows a maximum of 7 to be returned, because the 8th spot is needed for the parent block's signature.
Loading from the cache should speed up sync decisions, particularly when choose which peer to sync from. The greater the number of connected peers, the more significant this optimization will be. It should also reduce wasted network requests and data usage.
Adding this check prior to making a network request is a simple way to introduce the new cached summaries from BLOCK_SUMMARIES_V2 without having to rewrite a lot of the complex sync / peer comparison logic. Longer term we may want to rewrite that logic to read from the cache directly, but it doesn't make sense to introduce that level of risk at this point time, especially as the Synchronizer may be rewritten soon to prefer longer chains.
Even so, this is still quite a high risk commit so lots of testing will be needed.
The main difference here is that we now remove items from the onlineAccountsImportQueue in a batch, _after_ they have been imported. This prevents duplicates from being added to the queue in the previous time gap between them being removed and imported.
This caused large gaps with no presence data. They are removed when they expire, causing the local count to drop to zero, and the node would only start requesting them again once a peer had pushed one or more entries proactively.
