Our implementation of the "EQ" operator in Expected (conditional
operation) just compares the JSON represntation of the values.
This is almost always correct, but unfortunately incorrect for
sets - where we can have two equal sets despite having a
different order.
This patch just adds an (xfailing) test for this bug.
The bug itself can be fixed in the future in one of several ways
including changing the implementation of EQ, or changing the
serialization of sets so they'll always be sorted in the same
way.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20190909125147.16484-1-nyh@scylladb.com>
In this patch we implement the Expected parameter for the UpdateItem,
PutItem and DeleteItem operations. This parameter allows a conditional
update - i.e., do an update only if the existing value of the item
matches some condition.
This is the older form of conditional updates, but is still used by many
applications, including Amazon's Tic-Tac-Toe demo.
As usual, we do not yet provide isolation guarantees for read-modify-write
operations - the item is simply read before the modification, and there is
no protection against concurrent operation. This will of course need to be
addressed in the future.
The Expected parameter has a relatively large number of variations, and most
of them are supported by this code, except that currenly only two comparison
operators are supported (EQ and BEGINS_WITH) out of the 13 listed in the
documentation. The rest will be implemented later.
This patch also includes comprehensive tests for the Expected feature.
These tests are almost exhaustive, except for one missing part (labled FIXME) -
among the 13 comparison operations, the tests only check the EQ and BEGINS_WITH
operators. We'll later need to add checks to the rest of them as well.
As usual, all the tests pass on Amazon DynamoDB, and after this patch all
of them succeed on Alternator too.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20190905125558.29133-1-nyh@scylladb.com>
In order for Spark jobs to work correctly, a hardcoded PAY_PER_REQUEST
billing mode entry is returned when describing a table with
a DescribeTable request.
Also, one test case in test_describe_table.py is no longer marked XFAIL.
Message-Id: <a4e6d02788d8be48b389045e6ff8c1628240197c.1567688894.git.sarna@scylladb.com>
This patch adds a getting started document for alternator,
it explains how to start up a cluster that has an alternator
API port open and how to test that it works using either an
application or some simple and minimal python scripts.
The goal of the document is to get a user to have an up and
running docker based cluster with alternator support in the
shortest time possible.
As part of trying to make alternator more accessible
to users, we expect more documents to be created so
it seems like a good idea to give all of the alternator
docs their own directory.
When updating the second regular base column that is also a view
key, the code in Scylla will assume it only needs to update an entry
instead of replacing an old one. This leads to inconsitencies
exposed in the test case.
Message-Id: <5dfeb9f61f986daa6e480e9da4c7aabb5a09a4ec.1567599461.git.sarna@scylladb.com>
LSI tests are amended, so they no longer needlessly XPASS:
* two xpassing tests are no longer marked XFAIL
* there's an additional test for partial projection
that succeeds on DynamoDB and does not work fine yet in alternator
Message-Id: <0418186cb6c8a91de84837ffef9ac0947ea4e3d3.1567585915.git.sarna@scylladb.com>
The previous patch fixed test_describe_endpoints.py for a local run
without an AWS configuration. But when running with "--aws", we do
need to use that AWS configuration, and this patch fixes this case.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Even when running against a local Alternator, Boto3 wants to know the
region name, and AWS credentials, even though they aren't actually needed.
For a local run, we can supply garbage values for these settings, to
allow a user who never configured AWS to run tests locally.
Running against "--aws" will, of course, still require the user to
configure AWS.
The previous patch already fixed this for most tests, this patch fixes the
same issue in test_describe_endpoints.py, which had a separate copy of the
problematic code.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Even when running against a local Alternator, Boto3 wants to know the
region name, and AWS credentials, even though they aren't actually needed.
For a local run, we can supply garbage values for these settings, to
allow a user who never configured AWS to run tests locally.
Running against "--aws" will, of course, still require the user to
configure AWS.
Also modified the README to be clearer, and more focused on the local
runs.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20190708121420.7485-1-nyh@scylladb.com>
Unfortunately the previous 100s limit proved to be not enough
for creating tables with both local and global indexes attached
to them. Empirically 200s was chosen as a safe default,
as the longest test oscillated around 100s with the deviation of 10s.
With this patch, LocalSecondaryIndexes can be added to a table
during its creation. The implementation is heavily shared
with GlobalSecondaryIndexes and as such suffers from the same TODOs:
projections, describing more details in DescribeTable, etc.
We currently reserve the column name "attrs" for a map of attributes,
so the user is not allowed to use this name as a name of a key.
We plan to lift this reservation in a future patch, but until we do,
let's at least choose a more obscure name to forbid - in this patch ":attrs".
It is even less likely that a user will want to use this specific name
as a column name.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20190903133508.2033-1-nyh@scylladb.com>
Currently, we reserve the name ATTRS_COLUMN_NAME ("attrs") - the user
cannot use it as a key column name (key of the base table or GSI or LSI)
because we use this name for the attribute map we add to the schema.
Currently, if the user does attempt to create such a key column, the
result is undefined (sometimes corrupt sstables, sometimes outright crashes).
This patches fixes it to become a clean error, saying that this column name is
currently reserved.
The test test_create_table_special_column_name now cleanly fails, instead
of crashing Scylla, so it is converted from "skip" to "xfail".
Eventually we need to solve this issue completely (e.g., in rare cases
rename columns to allow us to reserve a name like ATTRS_COLUMN_NAME,
or alternatively, instead of using a fixed name ATTRS_COLUMN_NAME pick a
different one different from the key column names). But until we do,
better fail with a clear error instead of a crash.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20190901102832.7452-1-nyh@scylladb.com>
The file initially consists of a very simple case that succeeds
with `--aws` and expectedly fails without it, because the expression
is not implemented yet.
This adds a "alternator-address" and "alternator-port" configuration
options to the Docker image, so people can enable Alternator with
"docker run" with:
docker run --name some-scylla -d <image> --alternator-port=8080
Message-Id: <20190902110920.19269-1-penberg@scylladb.com>
When an unsupported expression parameter is encountered -
KeyConditionExpression, ConditionExpression or FilterExpression
are such - alternator will return an error instead of ignoring
the parameter.
This patch make two chagnes to the alternator stats:
1. It add estimated_histogram for the get, put, update and delete
operation
2. It changes the metrics naming, so the operation will be a label, it
will be easier to handle, perform operation and display in this way.
Signed-off-by: Amnon Heiman <amnon@scylladb.com>
The test_gsi_3, involving creating a GSI with two key columns which weren't
previously a base key, now passes, so drop the "xfail" marker.
We still have problems with such materialized views, but not in the simple
scenario tested by test_gsi_3.
Later we should create a new test for the scenario which still fails, if
any.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Creating an underlying materialized view with 2 regular base columns
is risky in Scylla, as second's column liveness will not be correctly
taken into account when ensuring view row liveness.
Still, in case specific conditions are met:
* the regular base column value is always present in the base row
* no TTLs are involved
then the materialized view will behave as expected.
Creating a GSI with 2 base regular columns issues a warning,
as it should be performed with care.
Message-Id: <5ce8642c1576529d43ea05e5c4bab64d122df829.1567159633.git.sarna@scylladb.com>
It is important that BillingMode should default to PROVISIONED, as it
does on DynamoDB. This allows old clients, which don't specify
BillingMode at all, to specify ProvisionedThroughput as allowed with
PROVISIONED.
Also added a test case for this case (where BillingMode is absent).
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20190829193027.7982-1-nyh@scylladb.com>
When querying on a missing index, DynamoDB returns different errors in
case the entire table is missing (ResourceNotFoundException) or the table
exists and just the index is missing (ValidationException). We didn't
make this distinction, and always returned ValidationException, but this
confuses clients that expect ResourceNotFoundException - e.g., Amazon's
Tic-Tac-Toe demo.
This patch adds a test for the first case (the completely missing table) -
we already had a test for the second case - and returns the correct
error codes. As usual the test passes against DynamoDB as well as Alternator,
ensure they behave the same.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20190829174113.5558-1-nyh@scylladb.com>
We needlessly split the trace-level log message for the request to two
messages - one containing just the operation's name, and one with the
parameters. Moreover we printed them in the opposite order (parameters
first, then the operation). So this patch combines them into one log
message.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20190829165341.3600-1-nyh@scylladb.com>
Alternator puts in the Scylla table a column called "attrs" for all the
non-key attributes. If the user happens to choose the same name, "attrs",
for one of the key columns, the result of writing two different columns
with the same name is a mess and corrupt sstables.
This test reproduces this bug (and works against DynamoDB of course).
Because the test doesn't cleanly fail, but rather leaves Scylla in a bad
state from which it can't fully recover, the test is marked as "skip"
until we fix this bug.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20190828135644.23248-1-nyh@scylladb.com>
Updating key columns is not allowed in UpdateItem requests,
but the series introducing GSI support for regular columns
also introduced redundant duplicates checks of this kind.
This condition is already checked in resolve_update_path helper function
and existing test_update_expression_cannot_modify_key test makes sure that
the condition is checked.
Message-Id: <00f83ab631f93b263003fb09cd7b055bee1565cd.1567086111.git.sarna@scylladb.com>
The test test_update_expression_cannot_modify_key() verifies that an
update expression cannot modify one of the key columns. The existing
test only tried the SET and REMOVE actions - this patch makes the
test more complete by also testing the ADD and DELETE actions.
This patch also makes the expected exception more picky - we now
expect that the exception message contains the word "key" (as it,
indeed, does on both DynamoDB and Alternator). If we get any other
exception, there may be a problem.
The test passed before this patch, and passes now as well - it's just
stricter now.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20190829135650.30928-1-nyh@scylladb.com>
The code previously used clustering_key::from_singular() to compute
a clustering key value. It works fine, but has two issues:
1. involves one redundant deserialization stage compared to
from_single_value
2. does not work with compound clustering keys, which can appear
when using indexes
With more GSI features implemented, tests with XPASS status are promoted
to being enabled.
One test case (test_gsi_describe) is partially done as DescribeTable
now contains index names, but we could try providing more attributes
(e.g. IndexSizeBytes and ItemCount from the test case), so the test
is left in the XFAIL state.
The DescribeTable request now contains the list of index names
as well. None of the attributes of the list are marked as 'required'
in the documentation, so currently the implementation provides
index names only.
In order to be able to create a Global Secondary Index over a regular
column, this column is upgraded from being a map entry to being a full
member of the schema. As such, it's possible to use this column
definition in the underlying materialized view's key.
In order to prepare alternator for adding regular columns to schema,
i.e. in order to create a materialized view over them,
the code is changed so that updating no longer assumes that only keys
are included in the table schema.
Since in the future we may want to have more regular columns
in alternator tables' schemas, the code is changed accordingly,
so all regular columns will be fetched instead of just the attribute
map.
If no regular column attributes are passed to PutItem, the attr
collector serializes an empty collection mutation nonetheless
and sends it. It's redundant, so instead, if the attr colector
is empty, the collection does not get serialized and sent to replicas.
Keeping an instance of client_state is a convenient way of being able
to use tracing for alternator. It's also currently used in paging,
so adding a client state to executor removes the need of keeping
a dummy value.
String views used in JSON serialization should use not only the pointer
returned by rapidjson, but also the string length, as it may contain
\0 characters.
Additionally, one unnecessary copy is elided.
Add a link to a longer document (currently, around 40 pages) about
DynamoDB's features and how we implemented or may implement them in
Alternator.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20190825121201.31747-2-nyh@scylladb.com>
