Summary:
The current idea is that the same MG binary can be used for single-node,
distributed master and distributed worker. The transactional engine in
the single-node and distributed master is the same: it determines the
transactional time and exposes all the "global" functionalities. In the
distributed worker the "global" functions must contact the master.
Reviewers: dgleich, mislav.bradac, buda
Reviewed By: dgleich
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1013
Summary:
The CSV importer used to generate non-unique edge IDs when
generating edges from multiple CSV files. This is incompatible with the
unique ID requirements introduced by the WAL. Tested and fixed in this
diff.
Reviewers: teon.banek, mferencevic
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D980
Summary:
My dear fellow Memgraphians. It's friday afternoon, and I am as ready to pop as WAL is to get reviewed...
What's done:
- Vertices and Edges have global IDs, stored in `VersionList`. Main storage is now a concurrent map ID->vlist_ptr.
- WriteAheadLog class added. It's based around buffering WAL::Op objects (elementraly DB changes) and periodically serializing and flusing them to disk.
- Snapshot recovery refactored, WAL recovery added. Snapshot format changed again to include necessary info.
- Durability testing completely reworked.
What's not done (and should be when we decide how):
- Old WAL file purging.
- Config refactor (naming and organization). Will do when we discuss what we want.
- Changelog and new feature documentation (both depending on the point above).
- Better error handling and recovery feedback. Currently it's all returning bools, which is not fine-grained enough (neither for errors nor partial successes, also EOF is reported as a failure at the moment).
- Moving the implementation of WAL stuff to .cpp where possible.
- Not sure if there are transactions being created outside of `GraphDbAccessor` and it's `BuildIndex`. Need to look into.
- True write-ahead logic (flag controlled): not committing a DB transaction if the WAL has not flushed it's data. We can discuss the gain/effort ratio for this feature.
Reviewers: buda, mislav.bradac, teon.banek, dgleich
Reviewed By: dgleich
Subscribers: mtomic, pullbot
Differential Revision: https://phabricator.memgraph.io/D958
Summary:
- Removed durability::Summary because it was wired into reader and stopped me from recovering WAL files.
- Refactored and renamed BufferedFile(Reader/Writer) to HashedFile(Reader/Writer).
- Vertex and edge counts in the snapshot are now hashed.
Breaking snapshot compatibility again (hashing), but since the previous version was not released, and we are not caching snapshots, the previous version does not need to be supported.
Reviewers: teon.banek, mislav.bradac, buda
Reviewed By: teon.banek, mislav.bradac
Subscribers: dgleich, pullbot
Differential Revision: https://phabricator.memgraph.io/D932
Summary:
Time csv_to_snapshot conversion and log it.
Check if writing csv_to_snapshot failed.
Extract LoadConfig from memgraph_bolt to config.hpp.
Read memgraph config in csv_to_snapshot for snapshot_directory.
Rename csv_to_snapshot to mg_import_csv.
Add tests for tools.
Run tools tests in apollo.
Reviewers: mislav.bradac, florijan, mferencevic, buda
Reviewed By: mferencevic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D931
Summary:
New snapshot structure:
- magic number
- snapshot version (old-version recovery not yet implemented)
- transaction snapshot (will be used in the WAL)
- the rest is as before (indices, vertices, edges)
Not backward compatible with the old snapshotting.
Does not improve error handling (user feedback). A task for that has been added.
Reviewers: buda, mislav.bradac, mferencevic, teon.banek
Reviewed By: teon.banek
Subscribers: teon.banek, dgleich, pullbot
Differential Revision: https://phabricator.memgraph.io/D912
Summary:
Add json and cppitertools to libs/CMakeLists.txt.
Import external projects as libraries.
This removes the need to use `add_dependencies` in order to link with
external project.
Extract common ExternalProject_Add function.
Add macro for easier addition of external libraries.
Reviewers: mislav.bradac, mferencevic
Reviewed By: mislav.bradac
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D845
Summary:
Setup scaffolding for building Memgraph tools.
Change `utils::Split` without delimiter to split on whitespace.
This should make `Split` behave just like Python's `str.split`, which is
more practical for splitting on word boundaries.
Add `utils::StartsWith` function.
Rewrite csv_to_snapshot to C++.
Reviewers: mferencevic
Reviewed By: mferencevic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D822
