Refs #8093
Refs /scylladb/scylla-tools-java#218
Adds keyword that can preface value tuples in (a, b, c) > (1, 2, 3)
expressions, forcing the restriction to bypass column sort order
treatment, and instead just create the raw ck bounds accordningly.
This is a very limited, and simple version, but since we only need
to cover this above exact syntax, this should be sufficient.
v2:
* Add small cql test
v3:
* Added comment in multi_column_restriction::slice, on what "mode" means and is for
* Added small document of our internal CQL extension keywords, including this.
v4:
* Added a few more cases to tests to verify multi-column restrictions
* Reworded docs a bit
v5:
* Fixed copy-paste error in comment
v6:
* Added negative (error) test cases
v7:
* Added check + reject of trying to combine SCYLLA_CLUST... slice and
normal one
Closes#8094
Nodes automatically ensure that the latest CDC generation's list of
streams is present in the streams description table. When a new
generation appears, we only need to update the table for this
generation; old generations are already inserted.
However, we've changed the description table (from
`cdc_streams_descriptions` to `cdc_streams_descriptions_v2`). The
existing mechanism only ensures that the latest generation appears in
the new description table. This commit adds an additional procedure that
rewrites the older generations as well, if we find that it is necessary
to do so (i.e. when some CDC log tables may contain data in these
generations).
Until now, the lists of streams in the `cdc_streams_descriptions` table
for a given generation were stored in a single collection. This solution
has multiple problems when dealing with large clusters (which produce
large lists of streams):
1. large allocations
2. reactor stalls
3. mutations too large to even fit in commitlog segments
This commit changes the schema of the table as described in issue #7993.
The streams are grouped according to token ranges, each token range
being represented by a separate clustering row. Rows are inserted in
reasonably large batches for efficiency.
The table is renamed to enable easy upgrade. On upgrade, the latest CDC
generation's list of streams will be (re-)inserted into the new table.
Yet another table is added: one that contains only the generation
timestamps clustered in a single partition. This makes it easy for CDC
clients to learn about new generations. It also enables an elegant
two-phase insertion procedure of the generation description: first we
insert the streams; only after ensuring that a quorum of replicas
contains them, we insert the timestamp. Thus, if any client observes a
timestamp in the timestamps table (even using a ONE query),
it means that a quorum of replicas must contain the list of streams.
We had Alternator's current compatibility with DynamoDB described in
two places - alternator.md and compatibility.md. This duplication was
not only unnecessary, in some places it led to inconsistent claims.
In general, the better description was in compatibility.md, so in
this patch we remove the compatibility section from alternator.md
and instead link to compatibility.md. There was a bit of information
that was missing in compatibility.md, so this patch adds it.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20210215203057.1132162-1-nyh@scylladb.com>
in all expressions' from Nadav Har'El.
This series fixes#5024 - which is about adding support for nested attribute
paths (e.g., a.b.c[2]) to Alternator. The series adds complete support for this
feature in ProjectionExpression, ConditionExpression, FilterExpression and
UpdateExpression - and also its combination with ReturnValues. Many relevant
tests - and also some new tests added in this series - now pass.
The first patch in the series fixes#8043 a bug in some error cases in
conditions, which was discovered while working in this series, and is
conceptually separate from the rest of the series.
Closes#8066
* github.com:scylladb/scylla:
alternator: correct implemention of UpdateItem with nested attributes and ReturnValues
alternator: fix bug in ReturnValues=UPDATED_NEW
alternator: implemented nested attribute paths in UpdateExpression
alternator: limit the depth of nested paths
alternator: prepare for UpdateItem nested attribute paths
alternator: overhaul ProjectionExpression hierarchy implementation
alternator: make parsed::path object printable
alternator-test: a few more ProjectionExpression conflict test cases
alternator-test: improve tests for nested attributes in UpdateExpression
alternator: support attribute paths in ConditionExpression, FilterExpression
alternator-test: improve tests for nested attributes in ConditionExpression
alternator: support attribute paths in ProjectionExpression
alternator: overhaul attrs_to_get handling
alternator-test: additional tests for attribute paths in ProjectionExpression
alternator-test: harden attribute-path tests for ProjectionExpression
alternator: fix ValidationException in FilterExpression - and more
Start improving CONTRIBUTING.md, as suggested in issue #8037:
1. Incorporate the few lines we had in coding-style.md into CONTRIBUTING.md.
This was mostly a pointer to Seastar's coding style anyway, so it's not
helpful to have a separate file which hopeful developers will not find
anyway.
2. Mention the Scylla developers mailing list, not just the Scylla users
mailing list. The Scylla developers mailing list is where all the action
happens, and it's very odd not to mention it.
3. The decisions that github pull requests are forbidden was retracted
a long time ago, so change the explanation on pull requests.
4. Some smaller phrasing changes.
Refs #8037.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20210214152752.1071313-1-nyh@scylladb.com>
This patch adds full support for nested attribute paths (e.g., a.b[3].c)
in UpdateExpression. After in previous patches we already added such
support for ProjectionExpression, ConditionExpression and FilterExpression
this means the nested attribute paths feature is now complete, so we
remove the warning from the documents. However, there is one last loose
end to tie and we will do it in the next patch: After this patch, the
combination of UpdateExpression with nested attributes and ReturnValues
is still wrong, and the test for it in test_returnvalues.py still xfails.
Note that previous patches already implemented support for attribute paths
in expression evaluations - i.e., the right-hand side of UpdateExpression
actions, and in this patch we just needed to implement the left hand side:
When an update action is on an attribute a.b we need to read the entire
content of the top-level a (an RWM operation), modify just the b part of
its json with the result of the action, and finally write back the entire
content of a. Of course everything gets complicated by the fact that we
can have multiple actions on multiple pieces of the same JSON, and we also
need to detect overlapping and conflicting actions (we already have this
detection in the attribute_path_map<> class we introduced in a previous
patch).
I decided to leave one small esoteric difference, reproduced by the xfailing
test_update_expression.py::test_nested_attribute_remove_from_missing_item:
As expected, "SET x.y = :val" fails for an item if its attribute x doesn't
exist or the item itself does not exist. For the update expression
"REMOVE x.y", DynamoDB fails if the attribute x doesn't exist, but oddly
silently passes if the entire item doesn't exist. Alternator does not
currently reproduce this oddity - it will fail this write as well.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
"
Currently inactive readers are stored in two different places:
* reader concurrency semaphore
* querier cache
With the latter registering its inactive readers with the former. This
is an unnecessarily complex (and possibly surprising) setup that we want
to move away from. This series solves this by moving the responsibility
if storing of inactive reads solely to the reader concurrency semaphore,
including all supported eviction policies. The querier cache is now only
responsible for indexing queriers and maintaining relevant stats.
This makes the ownership of the inactive readers much more clear,
hopefully making Benny's work on introducing close() and abort() a
little bit easier.
Tests: unit(release, debug:v1)
"
* 'unify-inactive-readers/v2' of https://github.com/denesb/scylla:
reader_concurrency_semaphore: store inactive readers directly
querier_cache: store readers in the reader concurrency semaphore directly
querier_cache: retire memory based cache eviction
querier_cache: delegate expiry to the reader_concurrency_semaphore
reader_concurrency_semaphore: introduce ttl for inactive reads
querier_cache: use new eviction notify mechanism to maintain stats
reader_concurrency_semaphore: add eviction notification facility
reader_concurrency_semaphore: extract evict code into method evict()
Related issue scylladb/sphinx-scylladb-theme#88
Once this commit is merged, the docs will be published under the new domain name https://scylla.docs.scylladb.com
Frequently asked questions:
Should we change the links in the README/docs folder?
GitHub automatically handles the redirections. For example, https://scylladb.github.io/sphinx-scylladb-theme/stable/examples/index.html redirects to https://sphinx-theme.scylladb.com/stable/examples/index.html
Nevertheless, it would be great to change URLs progressively to avoid the 301 redirections.
Do I need to add this new domain in the custom dns domain section on GitHub settings?
It is not necessary. We have already edited the DNS for this domain and the theme creates programmatically the required CNAME file. If everything goes well, GitHub should detect the new URL after this PR is merged.
The DNS doesn't seem to have the right SSL certificates
GitHub handles the certificate provisioning but is not aware of the subdomain for this repo yet. make multi-version will create a new file "CNAME". This is published in gh-pages branch, therefore GitHub should create the missing cert.
Closes#7877
A tool which lists all partitions contained in an sstable index. As all
partitions in an sstable are indexed, this tool can be used to find out
what partitions are contained in a given sstable.
The printout has the following format:
$pos: $human_readable_value (pk{$raw_hex_value})
Where:
* $pos: the position of the partition in the (decompressed) data file
* $human_readable_value: the human readable partition key
* $raw_hex_value: the raw hexadecimal value of the binary representation
of the partition key
For now the tool requires the types making up the partition key to be
specified on the command line, using the `--type|-t` command line
argument, using the Cassandra type class name notation for types.
As these are not assumed to be widely known, this patch includes a
document mapping all cql3 types to their Cassandra type class name
equivalent (but not just).
Signed-off-by: Botond Dénes <bdenes@scylladb.com>
Message-Id: <20201208092323.101349-1-bdenes@scylladb.com>
This PR adds the Sphinx documentation generator and the custom theme ``sphinx-scylladb-theme``. Once merged, the GitHub Actions workflow should automatically publish the developer notes stored under ``docs`` directory on http://scylladb.github.io/scylla
1. Run the command ``make preview`` from the ``docs`` directory.
3. Check the terminal where you have executed the previous command. It should not raise warnings.
3. Open in a new browser tab http://127.0.0.1:5500/ to see the generated documentation pages.
The table of contents displays the files sorted as they appear on GitHub. In a subsequent iteration, @lauranovich and I will submit an additional PR proposing a new folder organization structure.
Closes#7752
* github.com:scylladb/scylla:
docs: fixed warnings
docs: added theme
Add to the DynamoDB compatibility document, docs/alternator/compatibility.md,
a mention that Alternator streams are still an experimental features, and
how to turn it on (at this point CDC is no longer an experimental feature,
but Alternator Streams are).
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20201112184436.940497-1-nyh@scylladb.com>
Drop the adjective "experimental" used to describe Alternator in
docs/alternator/getting-started.md.
In Scylla, the word "experimental" carries a specific meaning - no support
for upgrades, not enough QA, not ready for general use) and Alternator is
no longer experimental in that sense.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20201112185249.941484-1-nyh@scylladb.com>
This patch adds a new document, docs/alternator/compatibility.md,
which focuses on what users switching from DynamoDB to Alternator
need to know about where Alternator differs from DynamoDB and which
features are missing.
The compatibility information in the old alternator.md is not deleted
yet. It probably should.
Fixes#7556
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20201110180242.716295-1-nyh@scylladb.com>
In commit de38091827 the two IO priority classes streaming_read
and streaming_write into just one. The document docs/isolation.md
leaves a lot to be desired (hint, hint, to anyone reading this and
can write content!) but let's at least not have incorrect information
there.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20201101102220.2943159-1-nyh@scylladb.com>
"
Focusing on different aspects of debugging Scylla. Also expand some of
the existing segments and fix some small issues around the document.
"
* 'debugging.md-advanced-guides/v1' of https://github.com/denesb/scylla:
docs/debugging.md: add thematic debugging guides
docs/debugging.md: tips and tricks: add section about optimized-out variables
docs/debugging.md: TLS variables: add missing $ to terminal command
docs/debugging.md: TUI: describe how to switch between windows
docs/debugging.md: troubleshooting: expand on crash on backtrace
When Alternator is enabled over HTTPS - by setting the
"alternator_https_port" option - it needs to know some SSL-related options,
most importantly where to pick up the certificate and key.
Before this patch, we used the "server_encryption_options" option for that.
However, this was a mistake: Although it sounds like these are the "server's
options", in fact prior to Alternator this option was only used when
communicating with other servers - i.e., connections between Scylla nodes.
For CQL connections with the client, we used a different option -
"client_encryption_options".
This patch introduces a third option "alternator_encryption_options", which
controls only Alternator's HTTPS server. Making it separate from the
existing CQL "client_encryption_options" allows both Alternator and CQL to
be active at the same time but with different certificates (if the user
so wishes).
For backward compatibility, we temporarily continue to allow
server_encryption_options to control the Alternator HTTPS server if
alternator_encryption_options is not specified. However, this generates
a warning in the log, urging the user to switch. This temporary workaround
should be removed in a future version.
This patch also:
1. fixes the test run code (which has an "--https" option to test over
https) to use the new name of the option.
2. Adds documentation of the new option in alternator.md and protocols.md -
previously the information on how to control the location of the
certificate was missing from these documents.
Fixes#7204.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20200930123027.213587-1-nyh@scylladb.com>
The wording on how CQL with SSL is configured was ambigous. Clarify the
text to explain that by default, it is *disabled*. We recommend to enable
it on port 9142 - but it's not a "default".
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20201014144938.653311-1-nyh@scylladb.com>
Let's build scylla-unified-package.tar.gz in build/<mode>/dist/tar for
symmetry. The old location is still kept for backward compatibility for
now. Also document the new official artifact location.
Message-Id: <20200917071131.126098-1-penberg@scylladb.com>
This patch adds support for 2 hash commands HDEL and HGETALL.
Internally it introduces the hashes_result_builder class to
read hashes and stored them in a std::map.
Other changes:
- one exception return string was fixed
- tests now use pytest.raises
Signed-off-by: Etienne Adam <etienne.adam@gmail.com>
Message-Id: <20200907202528.4985-1-etienne.adam@gmail.com>
This improves the build documentation beyond just packaging:
- Explain how the configure.py step works
- Explain how to build just executables and tests (for development)
- Explain how to build for specific build mode if you didn't specify a
build mode in configure.py step
- Fix build artifact locations, missing .debs, and add executables and
tests
Message-Id: <20200904084443.495137-1-penberg@iki.fi>
Documentation states that `SCYLLA_LWT_OPTIMIZATION_META_BIT_MASK`
is a 32-bit integer that represents bit mask. What it fails to mention
is that it's a unsigned value and in fact it takes value of 2147483648.
This is problematic for clients in languages that don't have unsigned
types (like Java).
This patch improves the documentation to make it clear that
`SCYLLA_LWT_OPTIMIZATION_META_BIT_MASK` is represented by unsigned
value.
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
Message-Id: <7166b736461ae6f3d8ffdf5733e810a82aa02abc.1599382184.git.piotr@scylladb.com>
We use a lot of TLS variables yet GDB is not of much help when working
with these. So in this patch I document where they are located in
memory, how to calculate the address of a known TLS variable and how to
find (identify) one given an address.
Signed-off-by: Botond Dénes <bdenes@scylladb.com>
Message-Id: <20200903131802.1068288-1-bdenes@scylladb.com>
Commit a6ad70d3da changed the format of
stream IDs: the lower 8 bytes were previously generated randomly, now
some of them have semantics. In particular, the least significant byte
contains a version (stream IDs might evolve with further releases).
This is a backward-incompatible change: the code won't properly handle
stream IDs with all lower 8 bytes generated randomly. To protect us from
subtle bugs, the code has an assertion that checks the stream ID's
version.
This means that if an experimental user used CDC before the change and
then upgraded, they might hit the assertion when a node attempts to
retrieve a CDC generation with old stream IDs from the CDC description
tables and then decode it.
In effect, the user won't even be able to start a node.
Similarly as with the case described in
d89b7a0548, the simplest fix is to rename
the tables. This fix must get merged in before CDC goes out of
experimental.
Now, if the user upgrades their cluster from a pre-rename version, the
node will simply complain that it can't obtain the CDC generation
instead of preventing the cluster from working. The user will be able to
use CDC after running checkAndRepairCDCStreams.
Since a new table is added to the system_distributed keyspace, the
cluster's schema has changed, so sstables and digests need to be
regenerated for schema_digest_test.
hget and hset commands using hashes internally, thus
they are not using the existing write_strings() function.
Limitations:
- hset only supports 3 params, instead of multiple field/value
list that is available in official redis-server.
- hset should return 0 when the key and field already exists,
but I am not sure it's possible to retrieve this information
without doing read-before-write, which would not be atomic.
I factorized a bit the query_* functions to reduce duplication, but
I am not 100% sure of the naming, it may still be a bit confusing
between the schema used (strings, hashes) and the returned format
(currently only string but array should come later with hgetall).
Signed-off-by: Etienne Adam <etienne.adam@gmail.com>
Message-Id: <20200830190128.18534-1-etienne.adam@gmail.com>
