Fixes root cause of a cascade of failures in replication code:
- Replica handling of deleting an edge is now corrected. Now tolerant of multiple edges of the same relationship type.
- Improved robustness: correct exception handling around failed stream of current WAL file. This now means a REPLICA failure will no longer prevent transactions on MAIN from performing WAL writes.
- Slightly better diagnostic messages, not user friendly but helps get developer to correct root cause quicker.
- Proactively remove vertex+edges during Abort rather than defer to GC to do that work, this included fixing constraints and indexes to be safe.
Co-authored-by: Andreja Tonev <andreja.tonev@memgraph.io>
Single (instance level) connection to a replica (messages from all databases get multiplexed through it)
ReplicationClient split in two: ReplicationClient and ReplicationStorageClient
New ReplicationClient, moved under replication, handles the raw connection, owned by MainRoleData
ReplicationStorageClient handles the storage <-> replica state machine and holds to a stream
Removed epoch and storage from *Clients
rpc::Stream proactively aborts on error and sets itself to a defunct state
Removed HandleRpcFailure, instead we simply log the error and let the FrequentCheck handle re-connection
replica_state is now a synced variable
ReplicaStorageClient state machine bugfixes
Single FrequentCheck that goes through DBMS
Moved ReplicationState under DbmsHandler
Moved some replication startup logic under the DbmsHandler's constructor
Removed InMemoryReplicationClient
CreateReplicationClient has been removed from Storage
Simplified GetRecoverySteps and made safer
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Co-authored-by: Gareth Lloyd <gareth.lloyd@memgraph.io>
* Interpreter transaction ID decoupled from storage transaction ID
* Transactional scope for indices, statistics and constraints
* Storage::Accessor now has 2 modes (unique and shared)
* Introduced ResourceLock to fix pthread mutex problems
* Split InfoQuery in two: non-transactional SystemInfoQuery and transactional DatabaseInfoQuery
* Replicable and durable statistics
* Bumped WAL/Snapshot versions
* Initial implementation of the Lamport clock
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Co-authored-by: Andreja Tonev <andreja.tonev@memgraph.io>
Concurrent access to the same query module had a race condition on the
pointer that was used to handle the custom memory management. With this
commit, a mapping has been added to keep information about what
thread used the pointer to handle the memory resources. This should be
fine since the respected query executions are running on a dedicated
thread. Access to the mapping itself is threadsafe. A simple RAII
wrapper for the mapping container has also been added for simpler
client-side use.
Add supernode vertex cache to account for long delta chains and modifications in the same module being independent of scanning of the nodes in the next iteration of the pulling mechanism.
* Decouple BoltSession and communication::bolt::Session
* Add CREATE/USE/DROP DATABASE
* Add SHOW DATABASES
* Cover WebSocket session
* Simple session safety implemented via RWLock
* Storage symlinks for backward. compatibility
* Extend the audit log with the DB info
* Add auth part
* Add tenant recovery
