* Add AUTH system tx deltas
* Add auth data RPC and handlers
* Support multiple system deltas in a single transaction
* Added e2e test
* Bugfix: KVStore segfault after move
---------
Co-authored-by: Gareth Lloyd <gareth.lloyd@memgraph.io>
* Split queries into system and data queries
* System queries are sequentially executed and generate separate transaction deltas
* System transaction try locks for 100ms
* last_commited_system_ts saved to DBMS durability
* Replicating CREATE/DROP DATABASE
* Sending a system snapshot if REPLICA behind
* Passing a copy of the gatekeeper::access as std::any to all functions that could call an async execution
* Removed delete_on_drop flag (we now always delete on drop)
* Using UUID as the directory name for databases
* DBMS durability update (added versioning and salient information)
* Automatic migration from previous version
* Interpreter can run some queries without a target database
* SHOW REPLICA returns the status of the currently active DB
* Returning UUID instead of db name in the RPC responses
* Using UUIDs for database specification in RPC (not name)
* FrequentCheck forces update on reconnect
* TimestampRpc will detect if a replica is behind, and will update client's state
* Safer SLK reads
* Split SHOW DATABASES in two SHOW DATABASES (list of current databases) and SHOW DATABASE a single string naming the current database
---------
Co-authored-by: Gareth Lloyd <gareth.lloyd@memgraph.io>
* Fix up REPLICA GetInfo and CreateSnapshot
Subtle bug where these actions were using the incorrect transactional
access while in REPLICA role. This casued timestamp to be incorrectly
bumped, breaking REPLICA from doing replication.
* Delay DNS resolution
Rather than resolve at endpoint creation, we will instread resolve only
on Socket connect. This allows k8s deployments to change their IP during
pod restarts.
* Minor sonarsource fixes
---------
Co-authored-by: Andreja <andreja.tonev@memgraph.io>
Co-authored-by: DavIvek <david.ivekovic@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
---------
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
---------
Co-authored-by: Andreja Tonev <andreja.tonev@memgraph.io>
Add a report for the case where a sync replica does not confirm within a timeout:
-Add a new exception: ReplicationException to be returned when one sync replica does not confirm the reception of messages (new data, new constraint/index, or for triggers)
-Update the logic to throw the ReplicationException when needed for insertion of new data, triggers, or creation of new constraint/index
-Add end-to-end tests to cover the loss of connection with sync/async replicas when adding new data, adding new constraint/indexes, and triggers
Add end-to-end tests to cover the creation and drop of indexes, existence constraints, and uniqueness constraints
Improved tooling function mg_sleep_and_assert to also show the last result when duration is exceeded
* Storage takes care of the saving of setting when a new replica is added
* Restore replicas at startup
* Modify interactive_mg_runner + memgraph to support that data-directory can be configured in CONTEXT
* Extend e2e test
* Correct typo
* Add flag to config to specify when replication should be stored (true by default when starting Memgraph)
* Remove un-necessary "--" in yaml file
* Make sure Memgraph stops if a replica can't be restored.
* Add UT covering the parsing of ReplicaStatus to/from json
* Add assert in e2e script to check that a port is free before using it
* Add test covering crash on Jepsen
* Make sure applciaiton crashes if it starts on corrupted replications' info
Starting with a non-reponsive replica is allowed.
* Add temporary startup flag: this is needed so jepsen do not automatically restore replica on startup of main. This will be removed in T0835
* Add config for replication client/server
* Add SSL to replication
* Add semi-sync replication
* Expose necessary information about replication
* Thread pool fix
* Set BasicResult value type to void
* Add basic communication process using commit timestamp
* Add file number to req
* Add proper recovery handling
* Allow loading of WALs with same seq num
* Allow always desired commit timestamp
* Set replica timestamp for operation
* Mark non-transactional timestamp as finished
* Add file transfer over RPC
* Snapshot transfer implementation
* Allow snapshot creation only for MAIN instances
* Replica and main can have replication clients
* Use only snapshots and WALs that are from the Main storage
* Add flush lock and expose buffer
* Add fstat for file size and TryFlushing method
* Use lseek for size
Co-authored-by: Antonio Andelic <antonio.andelic@memgraph.io>
* Add tests for multiple clients
* Use variant for RPC server and clients
* Using synchronized list for replication clients, extracted variant access to a function
* Set MAIN as default, add unregister function, add a name for replication clients
* Use the regular list for clients
* Use test fixture so storage directory is cleaned
* Use seq_cst for replication_state
Co-authored-by: Antonio Andelic <antonio.andelic@memgraph.io>
This implements the initial version of synchronous replication.
Currently, only one replica is supported and that isn't configurable.
To run the main instance use the following command:
```
./memgraph \
--main \
--data-directory main-data \
--storage-properties-on-edges \
--storage-wal-enabled \
--storage-snapshot-interval-sec 300
```
To run the replica instance use the following command:
```
./memgraph \
--replica \
--data-directory replica-data \
--storage-properties-on-edges \
--bolt-port 7688
```
You can then write/read data to Bolt port 7687 (the main instance) and also you
can read the data from the replica instance using Bolt port 7688.
NOTE: The main instance *must* be started without any data and the replica
*must* be started before any data is added to the main instance.
* Add basic synchronous replication test
* Using RWLock for replication stuff
Co-authored-by: Matej Ferencevic <matej.ferencevic@memgraph.io>
Co-authored-by: Antonio Andelic <antonio.andelic@memgraph.io>
