Summary:
Command id is necessary in remote produce to identify an ongoing pull
because a transaction can have multiple commands that all belong under
the same plan and tx id.
Reviewers: teon.banek, mtomic, buda
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1386
Summary:
Removing `AS_IS` from GraphView because it doesn't seem like it is necessary for query execution and it also has weird semantics (you might get a mix of old and new records). `Unwind`, `OrderBy` and `PullRemoteOrderBy` now use `OLD` graph view.
Remove AS_IS from GraphView
Fix query_cost_estimator tests
Fix query_expression_evaluator tests
Fix query_plan_match_filter_return tests
Fix query_plan_create_set_remove_delete tests
Fix query_plan_accumulate_aggregate tests
Reviewers: teon.banek, buda
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1390
Summary:
Since we are moving from boost to Capnp for serialization, it makes
sense to keep all of the LogicalOperator classes in LCP format. This
will make it easier to generate Capnp code.
Depends on D1361
Reviewers: buda, mferencevic, msantl, dgleich, ipaljak, mculinovic, mtomic
Reviewed By: mtomic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1362
Summary:
Pointers in AstTreeStorage can point to same nodes. These nodes
should be serialized(saved) only once when serializing Ast tree.
Same goes for deserializing(loading).
When deserializing nodes, one should not use storage Create method,
because it will add node which isn't completely loaded to storage vector.
Therefore, one should use new Deserialize method which doesn't
add node to storage vector. Inserting node into storage vector
is defered until all node data is loaded.
Pass pointer to saved uids set, instead of storage
Delete unused set
Reviewers: teon.banek, msantl
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1344
Summary:
Added a new markdown file for concepts and a new test to test the edge
case with upper bound.
Reviewers: teon.banek, mtomic, dgleich, buda, ipaljak
Reviewed By: teon.banek, dgleich
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1366
Summary:
When commiting/aborting a transaction in tx master engine, make a two
phase commit to all workers so they can stop all futures and clear
transactional cache.
Reviewers: dgleich, florijan
Reviewed By: dgleich
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1320
Summary:
Before we used `utils::Future` only where it's created by our `ThreadPool`.
I suggest in this diff that we use it everywhere, it's a bit more defensive and
should not have any downsides.
Reviewers: msantl, teon.banek
Reviewed By: msantl
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1316
Summary:
Add different priority VLOGs for distributed memgraph.
For level 3 you'll get logs for dispatching/consuming plans.
For level 4 you'll get logs for tx start/commit/abort, remote produce, remote
pull, remote result consume,
For level 5 there will be a log for each request/response made by the RPC
client.
Master log snippet P9
Worker log snippet P10
Reviewers: florijan, teon.banek
Reviewed By: florijan
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1296
Summary:
Remove "produce_" and "Produce" as prefix from all distributed stuff.
It's not removed in src/query/ stuff (operators).
Reviewers: dgleich
Reviewed By: dgleich
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1315
Summary:
Ensures that query plans are invalidated on the remote only when it's
guaranteed they will never be used on the master. This is done by
invalidating remote caches in the `CachedPlan` destructor.
There are two unplesant side-effects. First, an RPC call is made in an
object destructor. This is somewhat ugly, but not that different then
making an RPC call that must succeed in any other function. Note that
this does NOT slow down any query execution because the relevant
destructor is called by the skiplist garbage collector. The second ugly
side-effect is that in the unit test now we need to sleep to ensure the
skiplist GC destructs a cached plan before checking that it's
invalidated on the remote worker.
We might want to redesign this at some point.
Reviewers: teon.banek
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1302
Summary:
- Remove caches on workers as a result of plan expiration or race
during insertion.
- Extract caching functionality into a class.
- Minor refactor of Interpreter::operator()
- New RPC and test for it.
- Rename ConsumePlanRes to DispatchPlanRes for consistency, remove
return value as it's always true and never used.
- Interpreter is now constructed with a `GraphDb` reference. At the
moment only for reaching the `distributed::PlanDispatcher`, but in
the future we should probably use that primarily for planning.
I added a function to `PlanConsumer` that is only used for testing.
I prefer not doing this, but I felt this needed testing. I can remove
it now if you like.
Reviewers: teon.banek, msantl
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1292
Summary:
This fixes a bug where the planning would raise NotYetImplemented error,
due to preventing plan splitting while the operator is already on
master. For example, `MATCH (a), (b) CREATE (a)-[e:r]->(b) RETURN e`
would split the plan after Cartesian and before Create. Thus, the rest
of the plan would be on master, including the Accumulate before Produce.
We still can (and must) replace Accumulate with Synchronize but this
would fail due to unneeded check.
Reviewers: florijan, msantl
Reviewed By: msantl
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1272
Summary:
I have not thoroughly thought this through, especially the worker
destruction (is it legit to abort all running tx?), but it's tested to
abort during remote pull, what we need.
Also I improved error handling for vertex deletion failure during
remote pull (@dgleich).
Reviewers: teon.banek, msantl, dgleich
Reviewed By: dgleich
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1263
Summary:
If the `db` says we need to abort we should abort. There are two
places (in both `PullRemote` and `PullRemoteOrderBy`) where the check is made.
The first one is on the very beginning of the `Pull` method and the second one
is in the loop that checks/waits for remote results.
Reviewers: teon.banek, florijan
Reviewed By: florijan
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1265
Summary:
Usually a single RPC call takes 50us, which is a lot lower than our
millisecond sleep. Calling sleep with less than a ms duration may not
be really supported (due to timer granularity), but this change should
cause some sub-ms sleep.
Reviewers: florijan, msantl, mferencevic
Reviewed By: florijan
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1258
Summary:
During distributed execution, OrderBy is split across workers and the
master gets to merge those results via PullRemoteOrderBy. Since this
operator may be an input to almost any other operator, virtual accessors
to `input` have been added in LogicalOperator.
Depends on D1221
Reviewers: florijan, msantl, buda
Reviewed By: msantl
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1232
Summary:
Extracted `TypedValueVectorCompare` and `RemotePuller` from operators
so it can be reused.
The new `PullRemoteOrerBy` operator pulls one result from each worker and one
from master, relies on the fact that workers/master returned sorted results,
returns the next one in order, and pulls the source of that result to get the
next one.
Depends on D1215 that (at the moment) is still in review.
Reviewers: florijan, teon.banek
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1221
Summary:
- The expansion vertex gets created on the origin's worker
- The edge automatically gets created wherever necessary
- Vertex creation logic reuse
- End to end test
Reviewers: teon.banek, msantl
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1227
Summary:
- Add the said test
- Add `workerid` function
- Add random wait (enabled with flag) to `rpc::Client::Call` for network
latency simulation
Reviewers: buda, mferencevic, teon.banek
Reviewed By: buda, teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1222
Summary:
This may improve the query execution workload, because the Expand will
yield local results while it waits for remote ones. Note that we rely on
the fact that walking the graph produces results without any predetermined
order. Therefore, we can yield paths as we see fit. Enforcing the order
is done through OrderBy operator, and this change shouldn't affect that.
Reviewers: florijan, msantl, buda
Reviewed By: florijan
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1215
Summary:
- Add `database::GraphDb::GetWorkerIds()`
- Change `CreateNode` constructor API
- Make `CreateNode` distribute nodes uniformly over workers
Did not yet modify `CreateExpand`, coming in the next diff.
Reviewers: teon.banek
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1216
Summary:
This is still very much in progress. No advanced checks are done to
prevent planning unimplemented things. Basic Cartesian product should
work, for example `MATCH (a), (b) CREATE (a)-[:r]->(c)-[:r]->(b)`. But
anything more advanced may lead to undefined behaviour of the planner
and therefore execution. Use at your own risk!
Add ModifiedSymbols method to LogicalOperator
For planning Cartesian, we need information on which symbols are filled
by operator sub-trees. Currently, this is used to set symbols which
should be transferred over network. Later, they should be used to detect
whether filter expressions use symbols modified from Cartesian branches.
Then we will be able to ensure correct dependency of filters and their
behaviour.
Prepare DistributedPlan for multiple worker plans
Since Cartesian branches need to be split and handled by each worker, we
now dispatch multiple plans to workers.
Reviewers: florijan, msantl, buda
Reviewed By: florijan
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1208
Summary:
On the master cleanups are hooked directly into the transaction engine.
This is beneficial because the master might have bigger caches and we
want to clear them as soon as possible.
On the workers there is a periodic RPC call to the master about living
transactions, which takes care of releasing local caches. This is
suboptimal because long transactions will prevent cache GC (like with
data GC). It is however fairly simple.
Note that all cleanup is not done automatically and `RemotePull` has
been reduced accordingly. @msantl, please verify correctness and
consider if the code can be additionally simplified.
Reviewers: teon.banek, msantl
Reviewed By: msantl
Subscribers: pullbot, msantl
Differential Revision: https://phabricator.memgraph.io/D1202
Summary:
Pulls left op cursor and keeps the result, and then for each pull of
the right op cursor, adds all the left op results to produce a cartesian
product.
Reviewers: teon.banek, florijan
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1201
Summary:
Added a hidden flag, a int32 value, that represents the number of
milliseconds the thread that pulls remote results should sleep in case when the
local results are exhausted but there are still some remote results that are
pending.
Reviewers: teon.banek, florijan
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1198
Summary:
The same behaviour can now be achieved by passing a nullptr for input
operator.
Reviewers: florijan, msantl
Reviewed By: msantl
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1195
