The targets {dev|debug|release}-test run all unit tests, including
alternator/run. But this test requires the Scylla executable, which
wasn't among the dependencies. Fix it by adding build/$mode/scylla to
the dependency list.
Fixes#6855.
Tests: `ninja dev-test` after removing build/dev/scylla
Signed-off-by: Dejan Mircevski <dejan@scylladb.com>
It is legal for a user to create a table with name that has a
_scylla_cdc_log suffix. In such case, the table won't be treated as a
cdc log table, and does not require a corresponding base table to exist.
During refactoring done as a part of initial implemetation of of
Alternator streams (#6694), `is_log_for_some_table` started throwing
when trying to check a name like `X_scylla_cdc_log` when there was no
table with name `X`. Previously, it just returned false.
The exception originates inside `get_base_table`, which tries to return
the base table schema, not checking for its existence - which may throw.
It makes more sense for this function to return nullptr in such case (it
already does when provided log table name does not have the cdc log
suffix), so this patch adds an explicit check and returns nullptr when
necessary.
A similar oversight happened before (see #5987), so this patch also adds
a comment which explains why existence of `X_scylla_cdc_log` does not
imply existence of `X`.
Fixes: #6852
Refs: #5724, #5987
Currently, repair uses an integer to identify a repair job. The repair
id starts from 1 since node restart. As a result, different repair jobs
will have same id across restart.
To make the id more unique across restart, we can use an uuid in
addition to the integer id. We can not drop the use of the integer id
completely since the http api and nodetool use it.
Fixes#6786
The markdown syntax in the contribution section is incorrect, which is
why the links appear on the same line.
Improve the contribution section by making it more explicit what the
links are about.
Message-Id: <20200714070716.143768-1-penberg@scylladb.com>
This test usually fails, with the following error. Marking it "xfail" until
we can get to the bottom of this.
dynamodb = dynamodb.ServiceResource()
dynamodbstreams = <botocore.client.DynamoDBStreams object at 0x7fa91e72de80>
def test_get_records(dynamodb, dynamodbstreams):
# TODO: add tests for storage/transactionable variations and global/local index
with create_stream_test_table(dynamodb, StreamViewType='NEW_AND_OLD_IMAGES') as table:
arn = wait_for_active_stream(dynamodbstreams, table)
p = 'piglet'
c = 'ninja'
val = 'lucifers'
val2 = 'flowers'
> table.put_item(Item={'p': p, 'c': c, 'a1': val, 'a2': val2})
test_streams.py:316:
...
E botocore.exceptions.ClientError: An error occurred (Internal Server Error) when calling the PutItem operation (reached max retries: 3): Internal server error: std::runtime_error (cdc::metadata::get_stream: could not find any CDC stream (current time: 2020/07/15 17:26:36). Are we in the middle of a cluster upgrade?)
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Merged pull request https://github.com/scylladb/scylla/pull/6694
by Calle Wilund:
Implementation of DynamoDB streams using Scylla CDC.
Fixes#5065
Initial, naive implementation insofar that it uses 1:1 mapping CDC stream to
DynamoDB shard. I.e. there are a lot of shards.
Includes tests verified against both local DynamoDB server and actual AWS
remote one.
Note:
Because of how data put is implemented in alternator, currently we do not
get "proper" INSERT labels for first write of data, because to CDC it looks
like an update. The test compensates for this, but actual users might not
like it.
In the script test/alternator/run, which runs Scylla for the Alternator
tests, add the "--experimental-features=cdc" option, to allow us testing
the streams API whose implementation requires the experimenal CDC feature.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
* tools/java 50dbf77123...3eca0e3511 (1):
> config: Avoid checking options and filtering scylla.yaml
* tools/jmx 5820992...aa94fe5 (3):
> dist: redhat: reduce log spam from unpacking sources when building rpm
> Merge 'gitignore: fix typo and add scylla-apiclient/target/' from Benny
> apiclient: Bump Jackson version to 2.10.4
On .deb package with new relocatable package format, all files moved to
under scylla/ directory.
So we need to call ./scylla/install.sh on debian/rules, but it does not work
correctly, since install.sh does not support calling from other directory.
To support this, we need to changedir to scylla top directory before
copying files.
Merge pull request https://github.com/scylladb/scylla/pull/6834 by
Juliusz Stasiewicz:
NULLs used to give false positives in GT, LT, GEQ and LEQ ops performed upon
ALLOW FILTERING. That was a consequence of not distinguishing NULL from an
empty buffer.
This patch excludes NULLs on high level, preventing them from entering LHS
of any comparison, i.e. it assumes that any binary operation should return
false whenever the LHS operand is NULL (note: at the moment filters with
RHS NULL, such as ...WHERE x=NULL ALLOW FILTERING, return empty sets anyway).
Fixes#6295
* '6295-do-not-compare-nulls-v2' of github.com:jul-stas/scylla:
filtering_test: check that NULLs do not compare to normal values
cql3/restrictions: exclude NULLs from comparison in filtering
The data model is now
bplus::tree<Key = int64_t, T = array<entry>>
where entry can be cache_entry or memtable_entry.
The whole thing is encapsulated into a collection called "double_decker"
from patch #3. The array<T> is an array of T-s with 0-bytes overhead used
to resolve hash conflicts (patch #2).
branch:
tests: unit(debug)
tests before v7:
unit(debug) for new collections, memtable and row_cache
unit(dev) for the rest
perf(dev)
* https://github.com/xemul/scylla/commits/row-cache-over-bptree-9:
test: Print more sizes in memory_footprint_test
memtable: Switch onto B+ rails
row_cache: Switch partition tree onto B+ rails
memtable: Count partitions separately
token: Introduce raw() helper and raw comparator
row-cache: Use ring_position_comparator in some places
dht: Detach ring_position_comparator_for_sstables
double-decker: A combination of B+tree with array
intrusive-array: Array with trusted bounds
utils: B+ tree implementation
test: Move perf measurement helpers into header
impl_count_function doesn't explicitly initialize _count, so its correctness
depends on default initialization. Let's explicitly initialize _count to
make the code future proof.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Message-Id: <20200714162604.64402-1-raphaelsc@scylladb.com>
Option to control the alternator streams CDC query/shard range time
confidence interval, i.e. the period we enforce as timestamp threshold
when reading. The default, 10s, should be sufficient on a normal
cluster, but across DCs:, or with client timestamps or whatever, one might
need a larger window.
Subroutines needed by (in this case) streams implementation
moved from being file-static to class-static (exported).
To make putting handler routines in separate sources possible.
Because executor.cc is large and slow to compile.
Separation is nice.
Unfortunately, not all methods can be kept class-private,
since unrelated types also use them.
Reviewer suggested to instead place there is a top-level
header for export, i.e. not class-private at all.
I am skipping that for now, mainly because I can't come up
with a good file name. Can be part of a generate refactor
of helper routine organization in executor.
Add types exception overloads for ValidationException, ResourceNotFoundException, etc,
to avoid writing explicit error type as string everywhere (with the potential for
spelling errors ever present).
Also allows intellisense etc to complete the exception when coded.
To allow immediate json value conversion for types we
have TypeHelper<...>:s for.
Typed opt-get to get both automatic type conversion, _and_
find functionality in one call.
Tested operators are: `<` and `>`. Tests all types of NULLs except
`duration` because durations are explicitly not comparable. Values
to compare against were chosen arbitrarily.
The row cache memory footprint changed after switch to B+
because we no longer have a sole cache_entry allocation, but
also the bplus::data and bplus::node. Knowing their sizes
helps analyzing the footprint changes.
Also print the size of memtable_entry that's now also stored
in B+'s data.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
The change is the same as with row-cache -- use B+ with int64_t token
as key and array of memtable_entry-s inside it.
The changes are:
Similar to those for row_cache:
- compare() goes away, new collection uses ring_position_comparator
- insertion and removal happens with the help of double_decker, most
of the places are about slightly changed semantics of it
- flags are added to memtable_entry, this makes its size larger than
it could be, but still smaller than it was before
Memtable-specific:
- when the new entry is inserted into tree iterators _might_ get
invalidated by double-decker inner array. This is easy to check
when it happens, so the invalidation is avoided when possible
- the size_in_allocator_without_rows() is now not very precise. This
is because after the patch memtable_entries are not allocated
individually as they used to. They can be squashed together with
those having token conflict and asking allocator for the occupied
memory slot is not possible. As the closest (lower) estimate the
size of enclosing B+ data node is used
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
The row_cache::partitions_type is replaced from boost::intrusive::set
to bplus::tree<Key = int64_t, T = array_trusted_bounds<cache_entry>>
Where token is used to quickly locate the partition by its token and
the internal array -- to resolve hashing conflicts.
Summary of changes in cache_entry:
- compare's goes away as the new collection needs tri-compare one which
is provided by ring_position_comparator
- when initialized the dummy entry is added with "after_all_keys" kind,
not "before_all_keys" as it was by default. This is to make tree
entries sorted by token
- insertion and removing of cache_entries happens inside double_decker,
most of the changes in row_cache.cc are about passing constructor args
from current_allocator.construct into double_decker.empace_before()
- the _flags is extended to keep array head/tail bits. There's a room
for it, sizeof(cache_entry) remains unchanged
The rest fits smothly into the double_decker API.
Also, as was told in the previous patch, insertion and removal _may_
invalidate iterators, but may leave them intact. However, currently
this doesn't seem to be a problem as the cache_tracker ::insert() and
::on_partition_erase do invalidate iterators unconditionally.
Later this can be otimized, as iterators are invalidated by double-decker
only in case of hash conflict, otherwise it doesn't change arrays and
B+ tree doesn't invalidate its.
tests: unit(dev), perf(dev)
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
In next patches the entries having token on-board will be
moved onto B+-tree rails. For this the int64_t value of the
token will be used as B+ key, so prepare for this.
One corner case -- the after_all_keys tokens must be resolved
to int64::max value to appear at the "end" of the tree. This
is not the same as "before_all_keys" case, which maps to the
int64::min value which is not allowed for regular tokens. But
for the sake of B+ switch this is OK, the conflicts of token
raw values are explicitly resolved in next patches.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
The row cache (and memtable) code uses own comparators built on top
of the ring_position_comparator for collections of partitions. These
collections will be switched from the key less-compare to the pair
of token less-compare + key tri-compare.
Prepare for the switch by generalizing the ring_partition_comparator
and by patching all the non-collections usage of less-compare to use
one.
The memtable code doesn't use it outside of collections, but patch it
anyway as a part of preparations.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Next patches will generalize ring_position_comparator with templates
to replace cache_entry's and memtable_entry's comparators. The overload
of operator() for sstables has its own implementation, that differs from
the "generic" one, for smoother generalization it's better to detach it.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
The collection is K:V store
bplus::tree<Key = K, Value = array_trusted_bounds<V>>
It will be used as partitions cache. The outer tree is used to
quickly map token to cache_entry, the inner array -- to resolve
(expected to be rare) hash collisions.
It also must be equipped with two comparators -- less one for
keys and full one for values. The latter is not kept on-board,
but it required on all calls.
The core API consists of just 2 calls
- Heterogenuous lower_bound(search_key) -> iterator : finds the
element that's greater or equal to the provided search key
Other than the iterator the call returns a "hint" object
that helps the next call.
- emplace_before(iterator, key, hint, ...) : the call construct
the element right before the given iterator. The key and hint
are needed for more optimal algo, but strictly speaking not
required.
Adding an entry to the double_decker may result in growing the
node's array. Here to B+ iterator's .reconstruct() method
comes into play. The new array is created, old elements are
moved onto it, then the fresh node replaces the old one.
// TODO: Ideally this should be turned into the
// template <typename OuterCollection, typename InnerCollection>
// but for now the double_decker still has some intimate knowledge
// about what outer and inner collections are.
Insertion into this collection _may_ invalidate iterators, but
may leave intact. Invalidation only happens in case of hashing
conflict, which can be clearly seen from the hint object, so
there's a good room for improvement.
The main usage by row_cache (the find_or_create_entry) looks like
cache_entry find_or_create_entry() {
bound_hint hint;
it = lower_bound(decorated_key, &hint);
if (!hint.found) {
it = emplace_before(it, decorated_key.token(), hint,
<constructor args>)
}
return *it;
}
Now the hint. It contains 3 booleans, that are
- match: set to true when the "greater or equal" condition
evaluated to "equal". This frees the caller from the need
to manually check whether the entry returned matches the
search key or the new one should be inserted.
This is the "!found" check from the above snippet.
To explain the next 2 bools, here's a small example. Consider
the tree containing two elements {token, partition key}:
{ 3, "a" }, { 5, "z" }
As the collection is sorted they go in the order shown. Next,
this is what the lower_bound would return for some cases:
{ 3, "z" } -> { 5, "z" }
{ 4, "a" } -> { 5, "z" }
{ 5, "a" } -> { 5, "z" }
Apparently, the lower bound for those 3 elements are the same,
but the code-flows of emplacing them before one differ drastically.
{ 3, "z" } : need to get previous element from the tree and
push the element to it's vector's back
{ 4, "a" } : need to create new element in the tree and populate
its empty vector with the single element
{ 5, "a" } : need to put the new element in the found tree
element right before the found vector position
To make one of the above decisions the .emplace_before would need
to perform another set of comparisons of keys and elements.
Fortunately, the needed information was already known inside the
lower_bound call and can be reported via the hint.
Said that,
- key_match: set to true if tree.lower_bound() found the element
for the Key (which is token). For above examples this will be
true for cases 3z and 5a.
- key_tail: set to true if the tree element was found, but when
comparing values from array the bounding element turned out
to belong to the next tree element and the iterator was ++-ed.
For above examples this would be true for case 3z only.
And the last, but not least -- the "erase self" feature. Which is
given only the cache_entry pointer at hands remove it from the
collection. To make this happen we need to make two steps:
1. get the array the entry sits in
2. get the b+ tree node the vectors sits in
Both methods are provided by array_trusted_bounds and bplus::tree.
So, when we need to get iterator from the given T pointer, the algo
looks like
- Walk back the T array untill hitting the head element
- Call array_trusted_bounds::from_element() getting the array
- Construct b+ iterator from obtained array
- Construct the double_decker iterator from b+ iterator and from
the number of "steps back" from above
- Call double_decker::iterator.erase()
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
A plain array of elements that grows and shrinks by
constructing the new instance from an existing one and
moving the elements from it.
Behaves similarly to vector's external array, but has
0-bytes overhead. The array bounds (0-th and N-th
elemements) are determined by checking the flags on the
elements themselves. For this the type must support
getters and setters for the flags.
To remove an element from array there's also a nothrow
option that drops the requested element from array,
shifts the righter ones left and keeps the trailing
unused memory (so called "train") until reconstruction
or destruction.
Also comes with lower_bound() helper that helps keeping
the elements sotred and the from_element() one that
returns back reference to the array in which the element
sits.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
// The story is at
// https://groups.google.com/forum/#!msg/scylladb-dev/sxqTHM9rSDQ/WqwF1AQDAQAJ
This is the B+ version which satisfies several specific requirements
to be suitable for row-cache usage.
1. Insert/Remove doesn't invalidate iterators
2. Elements should be LSA-compactable
3. Low overhead of data nodes (1 pointer)
4. External less-only comparator
5. As little actions on insert/delete as possible
6. Iterator walks the sorted keys
The design, briefly is:
There are 3 types of nodes: inner, leaf and data, inner and leaf
keep build-in array of N keys and N(+1) nodes. Leaf nodes sit in
a doubly linked list. Data nodes live separately from the leaf ones
and keep pointers on them. Tree handler keeps pointers on root and
left-most and right-most leaves. Nodes do _not_ keep pointers or
references on the tree (except 3 of them, see below).
changes in v9:
- explicitly marked keys/kids indices with type aliases
- marked the whole erase/clear stuff noexcept
- disposers now accept object pointer instead of reference
- clear tree in destructor
- added more comments
- style/readability review comments fixed
Prior changes
**
- Add noexcepts where possible
- Restrict Less-comparator constraint -- it must be noexcept
- Generalized node_id
- Packed code for beging()/cbegin()
**
- Unsigned indices everywhere
- Cosmetics changes
**
- Const iterators
- C++20 concepts
**
- The index_for() implmenetation is templatized the other way
to make it possible for AVX key search specialization (further
patching)
**
- Insertion tries to push kids to siblings before split
Before this change insertion into full node resulted into this
node being split into two equal parts. This behaviour for random
keys stress gives a tree with ~2/3 of nodes half-filled.
With this change before splitting the full node try to push one
element to each of the siblings (if they exist and not full).
This slows the insertion a bit (but it's still way faster than
the std::set), but gives 15% less total number of nodes.
- Iterator method to reconstruct the data at the given position
The helper creates a new data node, emplaces data into it and
replaces the iterator's one with it. Needed to keep arrays of
data in tree.
- Milli-optimize erase()
- Return back an iterator that will likely be not re-validated
- Do not try to update ancestors separation key for leftmost kid
This caused the clear()-like workload work poorly as compared to
std:set. In particular the row_cache::invalidate() method does
exactly this and this change improves its timing.
- Perf test to measure drain speed
- Helper call to collect tree counters
**
- Fix corner case of iterator.emplace_before()
- Clean heterogenous lookup API
- Handle exceptions from nodes allocations
- Explicitly mark places where the key is copied (for future)
- Extend the tree.lower_bound() API to report back whether
the bound hit the key or not
- Addressed style/cleanness review comments
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
