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>
alternator/getting-started.md had a missing grave accent (`) character,
resulting in messed up rendering of the involved paragraph. Add the missing
quote.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20200827110920.187328-1-nyh@scylladb.com>
As suggested by Avi, let's move the tarballs from
"build/dist/<mode>/tar" to "build/<mode>/dist/tar" to retain the
symmetry of different build modes, and make the tarballs easier to
discover. While at it, let's document the new tarball locations.
Message-Id: <20200818100427.1876968-1-penberg@scylladb.com>
Previously system.paxos TTL was set as max(3h, gc_grace_seconds).
Introduce new per-table option named `paxos_grace_seconds` to set
the amount of seconds which are used to TTL data in paxos tables
when using LWT queries against the base table.
Default value is equal to `DEFAULT_GC_GRACE_SECONDS`,
which is 10 days.
This change allows to easily test various issues related to paxos TTL.
Fixes#6284
Tests: unit (dev, debug)
Co-authored-by: Alejo Sanchez <alejo.sanchez@scylladb.com>
Signed-off-by: Alejo Sanchez <alejo.sanchez@scylladb.com>
Signed-off-by: Pavel Solodovnikov <pa.solodovnikov@scylladb.com>
Message-Id: <20200816223935.919081-1-pa.solodovnikov@scylladb.com>
"
Let users disable the unencrypted native transport too by setting the port to
zero in the scylla.yaml configuration file.
Fixes#6997
"
* penberg-penberg/native-transport-disable:
docs/protocol: Document CQL protocol port configuration options
transport: Allow user to disable unencrypted native transport
maintainers.md contains a very helpful explanation of how to backport
Seastar fixes to old branches of Scylla, but has a tiny typo, which
this patch corrects.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20200811095350.77146-1-nyh@scylladb.com>
"
This is inspired by #6781. The idea is to make Scylla listen for CQL connections on port 9042 (where both old shard-aware and shard-unaware clients can still connect the traditional way). On top of that I added a new port, where everything works the same way, only the port from client's socket used to determine the shard No. to connect to. Desired shard No. is the result of `clientside_port % num_shards`.
The new port is configurable from scylla.yaml and defaults to 19042 (unencrypted, unless user configures encryption options and omits `native_shard_aware_transport_port_ssl` in DB config).
Two "SUPPORTED" tags are added: "SCYLLA_SHARD_AWARE_PORT" and "SCYLLA_SHARD_AWARE_PORT_SSL". For compatibility, "SCYLLA_SHARDING_ALGORITHM" is still kept.
Fixes#5239
"
* jul-stas-shard-aware-listener:
docs: Info about shard-aware listeners in protocol-extensions
transport: Added listener with port-based load balancing
Issue #6919 was caused by an incorrect assumption: I *assumed* that we see
the tracing session record, we can be sure that the event records for this
session had already been written. In this patch we add a paragraph to
the tracing documentation - docs/tracing.md, which explains that this
assumption is in fact incorrect:
1. On a multi-node setup, replicas may continue to write tracing events
after the coordinator "finished" (moved to background) the request
and wrote the session record.
2. Even on a single-node setup, the writes of the session record and the
individual events are asynchronous, and can happen in an unexpected
order (which is what happened in issue #6919).
Refs #6919.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20200727102438.1194314-1-nyh@scylladb.com>
This adds a '--io-setup N' command line option, which users can pass to
specify whether they want to run the "scylla_io_setup" script or not.
This is useful if users want to specify I/O settings themselves in
environments such as Kubernetes, where running "iotune" is problematic.
Fixes#6587
Instead, label the mapped volume by passing `:z` options to `-v`
argument, like we do for other mapped volumes in the `dbuild` script.
Passing the `--privileged` flag doesn't work after the most recent
Fedora update and anyway, using `:z` is the proper way to make sure the
mounted volume is accessible. Historically it was needed to be able to
open cores as well, but since 5b08e91bd this is not necessary as the
container is created with SYS_PTRACE capability.
Signed-off-by: Botond Dénes <bdenes@scylladb.com>
Message-Id: <20200703072703.10355-1-bdenes@scylladb.com>
Currently the section on "Debugging coredumps" only briefly mentions
relocatable binaries, then starts with an extensive subsection on how to
open cores generated by non-relocatable binaries. There is a subsection
about relocatable binaries, but it just contains some out-of-date
workaround without any context.
In this patch we completely replace this outdated and not very useful
subsection on relocatable binaries, with a much more extensive one,
documenting step-by-step a procedure that is known to work. Also, this
subsection is moved above the non-relocatable one. All our current
releases except for 2019.1 use relocatable binaries, so the subsection
about these should be the more prominent one.
Signed-off-by: Botond Dénes <bdenes@scylladb.com>
Message-Id: <20200630145655.159926-1-bdenes@scylladb.com>
This patch set adds a few new features in order to fix issue
The list of changes is briefly as follows:
- Add a new `LWT` flag to `cql3::prepared_metadata`,
which allows clients to clearly distinguish betwen lwt and
non-lwt statements without need to execute some custom parsing
logic (e.g. parsing the prepared query with regular expressions),
which is obviously quite fragile.
- Introduce the negotiation procedure for cql protocol extensions.
This is done via `cql_protocol_extension` enum and is expected
to have an appropriate mirroring implementation on the client
driver side in order to work properly.
- Implmenent a `LWT_ADD_METADATA_MARK` cql feature on top of the
aforementioned algorithm to make the feature negotiable and use
it conditionally (iff both server and client agrees with each
other on the set of cql extensions).
The feature is meant to be further utilized by client drivers
to use primary replicas consistently when dealing with conditional
statements.
* git@github.com:ManManson/scylla feature/lwt_prepared_meta_flag_2:
lwt: introduce "LWT" flag in prepared statement metadata
transport: introduce `cql_protocol_extension` enum and cql protocol extensions negotiation
We already have a docker image option to enable alternator on an unencrypted
port, "--alternator-port", but we forgot to also allow the similar option
for enabling alternator on an encrypted (HTTPS) port: "--alternator-https-port"
so this patch adds the missing option, and documents how to use it.
Note that using this option is not enough. When this option is used,
Alternator also requires two files, /etc/scylla/scylla.crt and
/etc/scylla/scylla.key, to be inserted into the image. These files should
contain the SSL certificate, and key, respectively. If these files are
missing, you will get an error in the log about the missing file.
Fixes#6583.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20200621125219.12274-1-nyh@scylladb.com>
The patch introduces two new features to aid with negotiating
protocol extensions for the CQL protocol:
- `cql_protocol_extensions` enum, which holds all supported
extensions for the CQL protocol (currently contains only
`LWT_ADD_METADATA_MARK` extension, which will be mentioned
below).
- An additional mechainsm of negotiating cql protocol extensions
to be used in a client connection between a scylla server
and a client driver.
These extensions are propagated in SUPPORTED message sent from the
server side with "SCYLLA_" prefix and received back as a response
from the client driver in order to determine intersection between
the cql extensions that are both supported by the server and
acknowledged by a client driver.
This intersection of features is later determined to be a working
set of cql protocol extensions in use for the current `client_state`,
which is associated with a particular client connection.
This way we can easily settle on the used extensions set on
both sides of the connection.
Currently there is only one value: `LWT_ADD_METADATA_MARK`, which
regulates whether to set a designated bit in prepared statement
metadata indicating if the statement at hand is an lwt statement
or not (actual implementation for the feature will be in a later
patch).
Each extension can also propagate some custom parameters to the
corresponding key. CQL protocol specification allows to send
a list of values with each key in the SUPPORTED message, we use
that to pass parameters to extensions as `PARAM=VALUE` strings.
In case of `LWT_ADD_METADATA_MARK` it's
`SCYLLA_LWT_OPTIMIZATION_META_BIT_MASK` which designates the
bitmask for LWT flag in prepared statement metadata in order to be
used for lookup in a client library. The associated bits of code in
`cql3::prepared_metadata` are adjusted to accomodate the feature.
The value for the flag is chosen on purpose to be the last bit
in the flags bitset since we don't want to possibly clash with
C* implementation in case they add more possible flag values to
prepared metadata (though there is an issue regarding that:
https://issues.apache.org/jira/browse/CASSANDRA-15746).
If it's fixed in upstream Cassandra, then we could synchronize
the value for the flag with them.
Also extend the underlying type of `flag` enum in
`cql3::prepared_metadata` to be `uint32_t` instead of `uint8_t`
because in either case flags mask is serialized as 32-bit integer.
In theory, shard-awareness extension support also should be
reworked in terms of provided minimal infrastructure, but for the
sake of simplicity, this is left to be done in a follow-up some
time later.
This solution eliminates the need to assume that all the client
drivers follow the CQL spec carefully because scylla-specific
features and protocol extensions could be enabled only in case both
server and client driver negotiate the supported feature set.
Tests: unit(dev, debug)
Signed-off-by: Pavel Solodovnikov <pa.solodovnikov@scylladb.com>
Commit 968177da04 has changed the schema
of cdc_topology_description and cdc_description tables in the
system_distributed keyspace.
Unfortunately this was a backwards-incompatible change: these tables
would always be created, irrespective of whether or not "experimental"
was enabled. They just wouldn't be populated with experimental=off.
If the user now tries to upgrade Scylla from a version before this change
to a version after this change, it will work as long as CDC is protected
b the experimental flag and the flag is off.
However, if we drop the flag, or if the user turns experimental on,
weird things will happen, such as nodes refusing to start because they
try to populate cdc_topology_description while assuming a different schema
for this table.
The simplest fix for this problem is to rename the tables. This fix must
get merged in before CDC goes out of experimental.
If the user upgrades his cluster from a pre-rename version, he will simply
have two garbage tables that he is free to delete after upgrading.
sstables and digests need to be regenerated for schema_digest_test since
this commit effectively adds new tables to the system_distributed keyspace.
This doesn't result in schema disagreement because the table is
announced to all nodes through the migration manager.
