Summary:
Added a new config parameter, replication timeout. This parameter sets the
upper limit to the replication phase and once the timeout exceeds, the
transaction engine stops accepting new transactions.
We could experience this timeout in two cases:
1. a network partition
2. majority of the cluster stops working
Reviewers: ipaljak
Reviewed By: ipaljak
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1893
Summary: Removing Kafka, auth and audit log features from HA instance for the time being.
Reviewers: mferencevic, msantl
Reviewed By: mferencevic, msantl
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1882
Summary:
Added index creation and deletion handling in StateDelta.
Also included an integration test that creates an index and makes sure that it
gets replicated by killing each peer eventually causing a leader re-election.
Reviewers: ipaljak
Reviewed By: ipaljak
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1886
Summary: `DataRpcClient` and `DataRpcServer` now work with both old and new record. This will be needed later when I replace `Cache` with `LruCache`.
Reviewers: msantl, teon.banek, ipaljak
Reviewed By: msantl, teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1875
Summary:
`EdgesIterable` is used for iterating over Edges in distributed memgraph. Because of lru cache there is a possibility of data getting evicted as someone iterates over it.
To prevent that `EdgesIterable` will lock that data and release it when it's deconstructed.
Reviewers: msantl
Reviewed By: msantl
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1868
Summary: Check that the import works without a specified field type.
Reviewers: teon.banek
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1877
Summary:
CachedDataLock is necessary for lru cache as remote data is no longer
persistent. Most methods internally handle this, but for methods that
return pointers or references to remote data, we need to manually
lock data.
Reviewers: msantl, ipaljak
Reviewed By: msantl
Subscribers: teon.banek, pullbot
Differential Revision: https://phabricator.memgraph.io/D1869
Summary: Benchmark shows that database with `ExistenceConstraints` is around 16% slower compared to case without `ExistenceConstraints`.
Reviewers: teon.banek, msantl, ipaljak, mferencevic
Reviewed By: msantl
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1876
Summary:
This is a short update which should explain the primary entrypoint to
query parsing and execution.
Reviewers: mtomic, llugovic
Reviewed By: mtomic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1856
Summary:
Our query parsing, planning and execution architecture was described on
Phabricator wiki pages, Phriction. This commit copies the said
documentation here, so that it's easier to access for all developers.
Additional benefit is tracking the changes and hopefully suggesting to
developers to keep it up to date.
Besides making a copy, the documentation has been updated to reflect the
current state of the codebase. Note that some things are still missing,
but what was written should now be correct.
Reviewers: mtomic, llugovic
Reviewed By: mtomic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1854
Summary:
Existence constraint ensures that all nodes with certain label have a certain property.
`ExistenceRule` defines label -> properties rule and `ExistenceConstraints` manages all
constraints.
Reviewers: msantl, ipaljak, teon.banek, mferencevic
Reviewed By: msantl, teon.banek, mferencevic
Subscribers: mferencevic, pullbot
Differential Revision: https://phabricator.memgraph.io/D1797
Summary:
RecordAccessor doesn't implement `operator<`, so it doesn't make sense
to have it inherit TotalOrdering.
Reviewers: mferencevic, msantl, vkasljevic
Reviewed By: vkasljevic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1866
Summary: Teon found this nit so we might fix it.
Reviewers: ipaljak
Reviewed By: ipaljak
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1860
Summary:
During the following scenario:
- start a HA cluster with 3 machines
- find the leader and start sending queries
- SIGTERM the leader but leave other 2 machines untouched
The leader would be stuck in the shutdown phase.
This was happening because during the shutdown phase of the Bolt server, a
`graph_db_accessor` would try to commit a transaction after we've already shut
down Raft server. Raft, although not running, is still thinking it's in the
Leader mode. Tx Engine calls the `SafeToCommit` method to Commit transactions,
and ends up in an infinite loop.
Since Raft was shut down it won't handle any of the incoming RPCs and won't
change it's mode.
The fix here is to shut down the Bolt server before Raft, so we don't have any
pending commits once Raft is shut down.
Reviewers: ipaljak
Reviewed By: ipaljak
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1853
Summary:
Added a new awesome function called `storageInfo`. This function
returns a list of key-value pairs containing the following (useful?)
information:
* number of vertices
* number of edges
* average degree
* memory usage
* disk usage
The current implementation is in `awesome_memgraph_functions` but it will end up
as a separate clause for better access control.
Reviewers: teon.banek, mtomic, mferencevic
Reviewed By: teon.banek
Subscribers: pullbot, buda
Differential Revision: https://phabricator.memgraph.io/D1850
Summary:
I've refactored the integration test for HA so we can reuse the common
parts like starting/stopping workers.
I've also added a test that triggers the log compaction and it checks that the
snapshot that has been transferred is the same as the origin one.
Reviewers: ipaljak
Reviewed By: ipaljak
Subscribers: mferencevic, pullbot
Differential Revision: https://phabricator.memgraph.io/D1847
Summary:
This change splits mg-communication into mg-communication and
mg-comm-rpc. The main reason for doing this, is to make separation of
enterprise features from community Memgraph more clear.
Reviewers: mferencevic, msantl
Reviewed By: msantl
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1844
Summary:
In Raft, we often need to access persistent state of the server
without modifying it. In order to speed up such operations, we
keep an in-memory copy of that state.
In this diff we make a copy of all persistent state except for
the log itself. Running our feature benchmark locally, we manage
to increase the throughput for cca 750 queries/s.
Reviewers: msantl
Reviewed By: msantl
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1843
Summary:
RuleBasedPlanner now generates only the regular ScanAll operations, and
Filter operations are appended as soon as possible. The newly added
Rewrite step, takes this operator tree and replaces viable Filter &
ScanAll operators with appropriate ScanAllBy<Index> operator. This
change ought to simplify the behaviour of DistributedPlanner when that
stage is moved before the indexed lookup rewrite.
Showing unoptimized plan in interactive planner is also supported.
Reviewers: mtomic, llugovic
Reviewed By: mtomic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1839
Summary:
All AST nodes had a member `uid_` that was used as a key in
`SymbolTable`. It is renamed to `symbol_pos_` and it appears only in
`Identifier`, `NamedExpression` and `Aggregation`, since only those types were
used in `SymbolTable`. SymbolGenerator is now responsible for creating symbols
in `SymbolTable` and assigning positions to AST nodes.
Cloning and serialization code is now simpler since there is no need to track
UIDs.
Reviewers: teon.banek
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1836
Summary:
In this part of log compaction for raft, I've implemented snapshooting
and snapshot recovery. I've also refactored the code a bit, so `RaftServer` now
has a pointer to the `GraphDb` and it can do some things by itself.
Log compaction requires some further work. Since snapshooting isn't synchronous
between peers, and each peer can work at their own pace, once we've compacted
the log so that the next log to be sent to peer `x` isn't available anymore, we
need to send the snapshot over the wire. This means that the next part will
contain the `InstallSnapshotRPC` and then maybe one more that will implement the
logic of sending `LogEntry` or the whole snapshot.
Reviewers: ipaljak
Reviewed By: ipaljak
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1834
Summary:
`ReplicationLog` had a classic off-by-one bug. The `valid_prefix`
variable wasn't set properly.
This diff also includes a poor man's version of a HA client. This client
assumes that all the HA instances run on a single machine and that the
corresponding Bold endpoints have open ports ranging from `7687` to
`7687 + num_machines - 1`.
This should make it easeir to test certain things, ie. disk usage, P25.
This test revealed the bug with `ReplicationLog`
Reviewers: ipaljak
Reviewed By: ipaljak
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1813
Summary:
Variable expansions cannot appear in merge patterns or after updates,
so they can only be planned with GraphState::OLD. Because of that, it makes
sense to remove GraphView parameter from them to reduce confusion.
Reviewers: teon.banek, llugovic
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1825
Summary:
Implement proper plan cloning using LCP instead of hacking it with
serialization.
depends on D1815
Reviewers: teon.banek, llugovic
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1816
