#### Problem
As we start supporting new storage formats, those account-meta
structs will be shared by different storage formats and thus need
a new home.
#### Summary of Changes
This PR creates meta.rs under account_storage and moves all the account-meta
structs out from append_vec.rs.
#### Current implementation of ReplicaAccountInfo restricts
possibilities for inflight account filtration
Current implementation includes transaction signature in
ReplicaAccountInfo. This approach does not allow to filter accounts by
matching other accounts in transaction in-flight (e. g. accept only
those accounts included in transactions for specific programs). Current
implementation forces to collect ALL accounts and transactions for some
period of time and perform such complex filtration afterwards.
#### Pass reference to transaction object instead of transaction
signature into ReplicaAccountInfo
Advanced in-flight filtration can be implemented in plugins by passing
reference to transaction for every update_account event. This change
doesn't bring any overhead comparing to current implementation (only
data type of reference is changed) and brings only minor changes in
source code.
There's no direct linkage between account-update events and transaction-events
Issue is linked with geyser plugin interface
Currently, there's no straightforward way to determine what notify_transaction call is related to particular update_account call. So, there's no simple way to determine what transaction caused what changes in accounts. This issue is especially valuable in case when several transactions modifies single account in the same slot.
Add txn_signature field to ReplicaTransactionInfo structure
This additional field will contain the signature of transaction which caused this account update event. This modification is not bringing significant overhead because all necessary information for such linkage already available inside Accounts::collect_accounts_to_store method
Problem
Slot status can be used of in other scenarios in addition to account information such as transactions, blocks. The current implementation is too tightly coupled.
Summary of Changes
Decouple the slot status notification from accounts notification. Created a new slot status notification module.
Use bulk insertion to Postgres at startup to reduce time taken for initial snapshot restore for postgres plugin. Avoid duplicate writes of accounts at startup. Doing account plugin notification and indexing in parallel.
Improved error handling for postgres plugin to show the real db issues for debug purpose
Added more metrics for postgres plugin.
Refactored plugin centric code out to a sub module from accounts_db and added unit tests
Summary of Changes
Create a plugin mechanism in the accounts update path so that accounts data can be streamed out to external data stores (be it Kafka or Postgres). The plugin mechanism allows
Data stores of connection strings/credentials to be configured,
Accounts with patterns to be streamed
PostgreSQL implementation of the streaming for different destination stores to be plugged in.
The code comprises 4 major parts:
accountsdb-plugin-intf: defines the plugin interface which concrete plugin should implement.
accountsdb-plugin-manager: manages the load/unload of plugins and provide interfaces which the validator can notify of accounts update to plugins.
accountsdb-plugin-postgres: the concrete plugin implementation for PostgreSQL
The validator integrations: updated streamed right after snapshot restore and after account update from transaction processing or other real updates.
The plugin is optionally loaded on demand by new validator CLI argument -- there is no impact if the plugin is not loaded.