Summary:
Looking for connected components in a random graph. This test performs the following:
- Generates a random graph that is NOT sequential in memory (otherwise itertion over edges is 2 or more times faster).
- Connectivity by iterating over all the edges.
- Ditto over vertices.
- Ditto over vertices in parallel.
Not done:
- Edge filtering based on XY. I could/should add that to see how it affects perf.
- Getting component info out from union-find.
Local results are encouraging. Iterating over the graph is the bottleneck. Still, I get connectivity of 10M vertices/edges in <7sec (parallel over vertices). Will test on 250M remote now.
Locally obtained results (20M/20M, 2 threads)
```
I1115 14:57:55.136875 357 otto_parallel.cpp:50] Generating 2000000 vertices...
I1115 14:58:19.057734 357 otto_parallel.cpp:74] Generated 2000000 vertices in 23.9208 seconds.
I1115 14:58:19.919221 357 otto_parallel.cpp:82] Generating 2000000 edges...
I1115 14:58:39.519951 357 otto_parallel.cpp:93] Generated 2000000 edges in 19.3398 seconds.
I1115 14:58:39.520349 357 otto_parallel.cpp:196] Running Edge iteration...
I1115 14:58:43.857264 357 otto_parallel.cpp:199] Done in 4.33691 seconds, result: 3999860270398
I1115 14:58:43.857316 357 otto_parallel.cpp:196] Running Vertex iteration...
I1115 14:58:49.498181 357 otto_parallel.cpp:199] Done in 5.64087 seconds, result: 4000090070787
I1115 14:58:49.498208 357 otto_parallel.cpp:196] Running Connected components - Edges...
I1115 14:58:54.232530 357 otto_parallel.cpp:199] Done in 4.73433 seconds, result: 323935
I1115 14:58:54.232570 357 otto_parallel.cpp:196] Running Connected components - Vertices...
I1115 14:59:00.412395 357 otto_parallel.cpp:199] Done in 6.17983 seconds, result: 323935
I1115 14:59:00.412422 357 otto_parallel.cpp:196] Running Parallel connected components - Vertices...
I1115 14:59:04.662087 357 otto_parallel.cpp:199] Done in 4.24967 seconds, result: 323935
I1115 14:59:04.662116 357 otto_parallel.cpp:196] Running Expansion...
I1115 14:59:13.913015 357 otto_parallel.cpp:199] Done in 9.25091 seconds, result: 323935
```
Reviewers: buda, mislav.bradac, dgleich, teon.banek
Reviewed By: buda, teon.banek
Subscribers: teon.banek, pullbot
Differential Revision: https://phabricator.memgraph.io/D982
Summary: Vertex and Edge now use Address for storing connections to other Edges and Vertices, to support distributed storage.
Reviewers: mislav.bradac, dgleich, buda
Reviewed By: mislav.bradac, dgleich
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D977
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:
Previously, named path symbols remained untracked as `new_symbols` during planning. This meant that
operator `Optional` would be left unaware of those symbols, and therefore not reset them to `Null`
if optional matching failed.
Test Optional operator will be aware of path symbols
Reviewers: florijan, mislav.bradac
Reviewed By: mislav.bradac
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D974
Summary:
Tests have been updated to catch this error and other behaviour. Other
than this change, `AND` should behave as before.
Reviewers: florijan, mislav.bradac
Reviewed By: florijan
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D970
Summary:
Use sigaction to register signal handlers.
This is preferred over `signal` function, according to `man 3p signal`.
Add global sig_atomic_t flag when shutting down.
Block other signal handlers when shutting down.
Reviewers: mislav.bradac, mferencevic
Reviewed By: mferencevic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D943
Summary:
Remove name from GraphDb.
Take GraphDb in query test macros instead of accessor.
Add is_accepting_transactions flag to GraphDb.
Reviewers: mislav.bradac, florijan, mferencevic
Reviewed By: mislav.bradac
Subscribers: mferencevic, pullbot
Differential Revision: https://phabricator.memgraph.io/D940
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:
Move QueryParts and Filters to a new file.
Reorganize FilterInfo struct.
Remove label filter if we do indexed scan by label.
Remove property filter used in indexed scan.
Reviewers: florijan
Reviewed By: florijan
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D915
Summary: Locked version. There are some benchmarks, it seems the lock won't be the bottleneck in the WAL (DB ops causing WAL delta insertions into it will be slower, flushing the WAL be slower).
Reviewers: buda, mislav.bradac, dgleich
Reviewed By: mislav.bradac
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D919
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: It wasn't used in MG, only in tests.
Reviewers: buda, dgleich, mislav.bradac
Reviewed By: mislav.bradac
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D909
Summary: This change increases the planning time, but should reduce memory consumption.
Reviewers: florijan, mislav.bradac
Reviewed By: mislav.bradac
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D901
Summary: In the current state, it was not possible to iterate, or even access a const map, or const set structure because of an incorrect implementation of "ConstAccessors".
Reviewers: mislav.bradac, teon.banek, buda
Reviewed By: teon.banek, buda
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D902
Summary:
This puts the whole installation and packaging under a single point of
entry. (Docker, DEB, RPM, etc.)
Rename alpha.dockerfile to beta.dockerfile
Use Debian Stretch for docker
Remove building old hardcoded compiler
Rename build_interpreter to build_memgraph
Remove unused config-file
Reviewers: mferencevic, buda
Reviewed By: mferencevic, buda
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D857
Summary:
- Removed BreadthFirstAtom, using EdgeAtom only with a Type enum.
- Both variable expansions (breadth and depth first) now have mandatory inner node and edge Identifiers.
- Both variable expansions use inline property filtering and support inline lambdas.
- BFS and variable expansion now have the same planning process.
- Planner modified in the following ways:
- Variable expansions support inline property filtering (two filters added to all_filters, one for inline, one for post-expand).
- Asserting against existing_edge since we don't support that anymore.
- Edge and node symbols bound after variable expansion to disallow post-expand filters to get inlined.
- Some things simplified due to different handling.
- BreadthFirstExpand logical operator merged into ExpandVariable. Two Cursor classes remain and are dynamically chosen from.
As part of planned planner refactor we should ensure that a filter is applied only once. The current implementation is very suboptimal for property filtering in variable expansions.
@buda: we will start refactoring this these days. This current planner logic is too dense and complex. It is becoming technical debt. Most of the time I spent working on this has been spent figuring the planning out, and I still needed Teon's help at times. Implementing the correct and optimal version of query execution (avoiding multiple potentially expensive filterings) was out of reach also due to tech debt.
Reviewers: buda, teon.banek
Reviewed By: teon.banek
Subscribers: pullbot, buda
Differential Revision: https://phabricator.memgraph.io/D852
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:
- The new BFS syntax implemented as proposed.
- AST BreadthFirstAtom now uses EdgeAtom members: has_range_{true}, upper_bound_, lower_bound_
- Edges data structure now handles all the edge filtering (single or multiple edges), to ease planning. Additional edge filtering (additional Filter op in the plan) is removed. AST EdgeTypeTest is no longer used and is removed.
Current state is stable but there are things left to do:
- BFS property filtering.
- BFS lower_bound_ support.
- Support for lambdas in variable length expansion. This includes obligatory (even if not user_defined) inner_node and inner_edge symbols for easier handling.
- Code-sharing between BFS and variable length expansions.
I'll add asana tasks (and probably start working on them immediately) when/if this lands.
Reviewers: buda, teon.banek, mislav.bradac
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D836
Summary: - modified all utils/algorithm functions to be inline and in the utils namespace
Reviewers: teon.banek
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D830
Summary:
I started with cleaning flags up (removing unused ones, documenting undocumented ones). There were some flags to remove in `QueryEngine`. Seeing how we never use hardcoded queries (AFAIK last Mislav's testing also indicated they aren't faster then interpretation), when removing those unused flags the `QueryEngine` becomes obsolete. That means that a bunch of other stuff becomes obsolete, along with the hardcoded queries. So I removed it all (this has been discussed and approved on the daily).
Some flags that were previously undocumented in `docs/user_technical/installation` are now documented. The following flags are NOT documented and in my opinion should not be displayed when starting `./memgraph --help` (@mferencevic):
```
query_vertex_count_to_expand_existsing (from rule_based_planner.cpp)
query_max_plans (rule_based_planner.cpp)
```
If you think that another organization is needed w.r.t. flag visibility, comment.
@teon.banek: I had to remove some stuff from CMakeLists to make it buildable. Please review what I removed and clean up if necessary if/when this lands. If the needed changes are minor, you can also comment.
Reviewers: buda, mislav.bradac, teon.banek, mferencevic
Reviewed By: buda, mislav.bradac
Subscribers: pullbot, mferencevic, teon.banek
Differential Revision: https://phabricator.memgraph.io/D825
