The unit test executes a simplified repair scenario by:
- producing a random stream of mutation mutation_fragments,
- convering them to repair_rows_on_wire,
- convering them to list of repair_rows using the conversion logic
extracted in previous commits from repair_meta,
- flushing the rows to an sstable using the logic extracted in previous
commits from repair_meta,
- comparing the sstable contents with the originally produced mutation
fragments.
The test checks only the flushing part and is not concerned with any
other piece of the repair pipeline.
Based on perf_simple_query, just bashes data into CL using
normal distribution min/max data chunk size, allowing direct
freeing of segments, _but_ delayed by a normal dist as well,
to "simulate" secondary delay in data persistance.
Needs more stuff.
Some baseline measurements on master:
--min-flush-delay-in-ms 10 --max-flush-delay-in-ms 200
--commitlog-use-hard-size-limit true
--commitlog-total-space-in-mb 10000 --min-data-size 160 --max-data-size 1024
--smp1
median 2065648.59 tps ( 1.1 allocs/op, 0.0 tasks/op, 1482 insns/op)
median absolute deviation: 48752.44
maximum: 2161987.06
minimum: 1984267.90
--min-data-size 256 --max-data-size 16384
median 269385.25 tps ( 2.2 allocs/op, 0.7 tasks/op, 3244 insns/op)
median absolute deviation: 15719.13
maximum: 323574.43
minimum: 228206.28
--min-data-size 4096 --max-data-size 61440
median 67734.22 tps ( 6.4 allocs/op, 2.9 tasks/op, 9153 insns/op)
median absolute deviation: 2070.93
maximum: 82833.17
minimum: 61473.57
--min-data-size 61440 --max-data-size 1843200
median 2281.37 tps ( 79.7 allocs/op, 43.5 tasks/op, 202963 insns/op)
median absolute deviation: 128.87
maximum: 3143.84
minimum: 2140.80
--min-data-size 368640 --max-data-size 6144000
median 679.76 tps (225.5 allocs/op, 116.3 tasks/op, 662700 insns/op)
median absolute deviation: 39.30
maximum: 1148.95
minimum: 586.86
Actual throughput obviously meaningless, as it is run on my slow
machine, but IPS might be relevant.
Note that transaction throughput plummets as we increase median data
sizes above ~200k, since we then more or less always end up replacing
buffers in every call.
Closes#10230
The flat_mutation_reader files were conflated and contained multiple
readers, which were not strictly necessary. Splitting optimizes both
iterative compilation times, as touching rarely used readers doesn't
recompile large chunks of codebase. Total compilation times are also
improved, as the size of flat_mutation_reader.hh and
flat_mutation_reader_v2.hh have been reduced and those files are
included by many file in the codebase.
With changes
real 29m14.051s
user 168m39.071s
sys 5m13.443s
Without changes
real 30m36.203s
user 175m43.354s
sys 5m26.376s
Closes#10194
There's nothing specific to scylla in the lister
classes, they could (and maybe should) be part of
the seastar library.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Memtables are a replica-side entity, and so are moved to the
replica module and namespace.
Memtables are also used outside the replica, in two places:
- in some virtual tables; this is also in some way inside the replica,
(virtual readers are installed at the replica level, not the
cooordinator), so I don't consider it a layering violation
- in many sstable unit tests, as a convenient way to create sstables
with known input. This is a layering violation.
We could make memtables their own module, but I think this is wrong.
Memtables are deeply tied into replica memory management, and trying
to make them a low-level primitive (at a lower level than sstables) will
be difficult. Not least because memtables use sstables. Instead, we
should have a memtable-like thing that doesn't support merging and
doesn't have all other funky memtable stuff, and instead replace
the uses of memtables in sstable tests with some kind of
make_flat_mutation_reader_from_unsorted_mutations() that does
the sorting that is the reason for the use of memtables in tests (and
live with the layering violation meanwhile).
Test: unit (dev)
Closes#10120
"
The table lists connected clients. For this the clients are
stored in real table when they connect, update their statuses
when needed and remove^w tombstone themselves when they
disconnect. On start the whole table is cleared.
This looks weird. Here's another approach (inspired by the
hackathon project) that makes this table a pure virtual one.
The schema is preserved so is the data returned.
The benefits of doing it virtual are
- no on-disk updates while processing clients
- no potentially failing updates on non-failing disconnect
- less usage of the global qctx thing
- less calls to global storage_proxy
- simpler support for thrift and alternator clients (today's
table implementation doesn't track them)
- the need to make virtual tables reg/unreg dynamic
branch: https://github.com/xemul/scylla/tree/br-clients-virtual-table-4
tests: manual(dev), unit(dev)
The manual test used 80-shards node and 1M connections from
1k different IP addresses.
"
* 'br-clients-virtual-table-4' of https://github.com/xemul/scylla:
test: Add cql-pytest sanity test for system.clients table
client_data: Sanitize connection_notifier
transport: Indentation fix after previous patch
code: Remove old on-disk version of system.clients table
system_keyspace: Add clients_v virtual table
protocol_server: Add get_client_data call
transport: Track client state for real
transport: Add stringifiers to client_data class
generic_server: Gentle iterator
generic_server: Type alias
docs: Add system.clients description
Add tests for new expr::visit to ensure that it is working correctly.
expr::visit had a hidden bug where trying to return a reference
actually returned a reference to freed location on the stack,
so now there are tests to ensure that everything works.
Sadly the test `expr_visit_const_ref` also passes
before the fix, but at lest expr_visit_ref doesn't compile before the fix.
It would be better to test this by taking references returned
by std::visit and expr::visit and checking that they point
to the same address in memory, but I can't do this
because I would have to access private field of expression.
Signed-off-by: Jan Ciolek <jan.ciolek@scylladb.com>
Now the connection_notifier is all gone, only the client_data bits are left.
To keep it consistent -- rename the files.
Also, while at it, brush up the header dependencies and remove the not
really used constexprs for client states.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Adds a number of utilities for working with boost::outcome::result
combined with exception_container. The utilities are meant to help with
migration of the existing code to use the boost::outcome::result:
- `exception_container_throw_policy` - a NoValuePolicy meant to be used
as a template parameter for the boost::outcome::result. It protects
the caller of `result::value()` and `result::error()` methods - if the
caller wishes to get a value but the result has an error
(exception_container in our case), the exception in the container will
be thrown instead. In case it's the other way around,
boost::outcome::bad_result_access is thrown.
- `result_parallel_for_each` - a version of `parallel_for_each` which is
aware of results and returns a failed result in case any of the
parallel invocations return a failed result.
- `result_into_future` - converts a result into a future. If the result
holds a value, converts it into make_ready_future; if it holds an
exception, the exception is returned as make_exception_future.
- `then_ok_result` takes a `future<T>` and converts it into
a `future<result<T>>`.
- `result_wrap` adapts a callable of type `T -> future<result<T>>` and
returns a callable of type `result<T> -> future<result<T>>`.
Adds `exception_container` - a helper type used to hold exceptions as a
value, without involving the std::exception_ptr.
The motivation behind this type is that it allows inspecting exception's
type and value without having to rethrow that exception and catch it,
unlike std::exception_ptr. In our current codebase, some exception
handling paths need to rethrow the exception multiple times in order to
account it into metrics or encode it as an error response to the CQL
client. Some types of exceptions can be thrown very frequently in case
of overload (e.g. timeouts) and inspecting those exceptions with
rethrows can make the overload even worse. For those kinds of exceptions
it is important to handle them as cheaply as possible, and
exception_container used with conjunction with boost::outcome::result
can help achieve that.
In commit d72465531e we fixed the building
of relocatable packages of submodules (tools/java, etc.) to use the
top-level Scylla's version. However, if on an active working directory
Scylla's version changes - as we just did from 4.7 to 5.0 - these
relocatable packages are not rebuilt with the new version number, and as
a result some of our scripts (such as the docker build) can't find them.
Because the build-submodule-reloc rule depends on the files
build/SCYLLA-{PRODUCT,VERSION,RELEASE}-FILE (which is what the
aforementioned commit did), in this patch we add those files as a
dependency whenever build-submodule-reloc is used. This means that if
any of these files change, we rebuild the relocatable packages and
anything depending on them (e.g., Debian packages).
Fixes#10018.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20220202131248.1610678-1-nyh@scylladb.com>
The new service is responsible for:
* spreading forward_request execution across multiple nodes in cluster
* collecting forward_request execution results and merging them
`forward_service::dispatch` method takes forward_request as an
argument, and forwards its execution to group of other nodes (using rpc
verb added in previous commits). Each node (in the group chosen by
dispatch method) is provided with forward_request, which is no different
from the original argument except for changed partition ranges. They are
changed so that vnodes contained in them are owned by recipient node.
Executing forward_request is realized in `forward_service::execute`
method, that is registered to be called on FORWARD_REQUEST verb receipt.
Process of executing forward_request consists of mocking few
non-serializable object (such as `cql3::selection`) in order to create
`service:pager:query_pagers::pager` and `cql3::selection::result_set_builder`.
After pager and result_set_builder creation, execution process resembles
what might be seen in select_statement's execution path.
Except for the verb addition, this commit also defines forward_request
and forward_result structures, used as an argument and result of the new
rpc. forward_request is used to forward information about select
statement that does count(*) (or other aggregating functions such as
max, min, avg in the future). Due to the inability to serialize
cql3::statements::select_statement, I chose to include
query::read_command, dht::partition_range_vector and some configuration
options in forward_request. They can be serialized and are sufficient
enough to allow creation of service::pager::query_pagers::pager.
We perform a bunch of schema changes with different values of
`migration_manager::_group0_history_gc_duration` and check if entries
are cleared according to this setting.
Objects of this type will be serialized and sent as commands to the
group 0 state machine. They contain a set of mutations which modify
group 0 tables (at this point: schema tables and group 0 history table),
the 'previous state ID' which is the last state ID present in the
history table when the operation described by this command has started,
and the 'new state ID' which will be appended to the history table if
this change is successful (successful = the previous state ID is still
equal to the last state ID in the history table at the moment of
application). It also contains the address of the node which constructed
this command.
The state ID mechanism will be described in more detail in a later
commit.
Instead of lengthy blurbs, switch to single-line, machine-readable
standardized (https://spdx.dev) license identifiers. The Linux kernel
switched long ago, so there is strong precedent.
Three cases are handled: AGPL-only, Apache-only, and dual licensed.
For the latter case, I chose (AGPL-3.0-or-later and Apache-2.0),
reasoning that our changes are extensive enough to apply our license.
The changes we applied mechanically with a script, except to
licenses/README.md.
Closes#9937
* 'gleb/sp-idl-v1' of github.com:scylladb/scylla-dev:
storage_proxy: move all verbs to the IDL
idl-compiler: allow const references in send() parameter list
idl-compiler: support smart pointers in verb's return value
idl-compiler: support multiple return value and optional in a return value
idl-compiler: handle :: at the beginning of a type
idl-compiler: sending one way message without timeout does not require ret value specialization as well
storage_proxy: convert more address vectors to inet_address_vector_replica_set
Split off of #9835.
The series removes extraneous includes of lister.hh from header files
and adds a unit test for lister::scan_dir to test throwing an exception
from the walker function passed to `scan_dir`.
Test: unit(dev)
Closes#9885
* github.com:scylladb/scylla:
test: add lister_list
lister: add more overloads of fs::path operator/ for std::string and string_view
resource_manager: remove unnecessary include of lister.hh from header file
sstables: sstable_directory: remove unncessary include of lister.hh from header file
configure.py uses the deprecated Python function tempfile.mktemp().
Because this function is labeled a "security risk" it is also a magnet
for automated security scanners... So let's replace it with the
recommended tempfile.mkstemp() and avoid future complaints.
The actual security implications of this mktemp() call is negligible to
non-existent: First it's just the build process (configure.py), not
the build product itself. Second, the worst that an attacker (which
needs to run in the build machine!) can do is to cause a compilation
test in configure.py to fail because it can't write to its output file.
Reported by @srikanthprathi
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20220111121924.615173-1-nyh@scylladb.com>
Test the lister class.
In particular the ability to abort the lister
when the walker function throws an exception.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
distributed_loader is replica-side thing, so it belongs in the
replica module ("distributed" refers to its ability to load
sstables in their correct shards). So move it to the replica
module.
Move the ::database, ::keyspace, and ::table classes to a new replica
namespace and replica/ directory. This designates objects that only
have meaning on a replica and should not be used on a coordinator
(but note that not all replica-only classes should be in this module,
for example compaction and sstables are lower-level objects that
deserve their own modules).
The module is imperfect - some additional classes like distributed_loader
should also be moved, but there is only one way to untie Gordian knots.
Closes#9872
* github.com:scylladb/scylla:
replica: move ::database, ::keyspace, and ::table to replica namespace
database: Move database, keyspace, table classes to replica/ directory
The database, keyspace, and table classes represent the replica-only
part of the objects after which they are named. Reading from a table
doesn't give you the full data, just the replica's view, and it is not
consistent since reconciliation is applied on the coordinator.
As a first step in acknowledging this, move the related files to
a replica/ subdirectory.
Which configures seastar to act more appropriate to a tool app. I.e.
don't act as if it owns the place, taking over all system resources.
These tools are often run on a developer machine, or even next to a
running scylla instance, we want them to be the least intrusive
possible.
Also use the new tool mode in the existing tools.
Signed-off-by: Botond Dénes <bdenes@scylladb.com>
Message-Id: <20211220143104.132327-1-bdenes@scylladb.com>
When you run "configure.py", the result is not only the creation of
./build.ninja - it also creates build/<mode>/seastar/build.ninja
and build/<mode>/abseil/build.ninja. After a "rm -r build" (or "ninja
clean"), "ninja" will no longer work because those files are missing
when Scylla's ninja tries to run ninja in those internal project.
So we need to add a dependency, e.g., that running ninja in Seastar
requires build/<mode>/seastar/build.ninja to exist, and also say
that the rule that (re)runs "configure.py" generates those files.
After this patch,
configure.py --with-some-parameters --of-your-choice
rm -r build
ninja
works - "ninja" will re-run configure.py with the same parameters
when it needs Seastar's or Abseil's build.ninja.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20211230133702.869177-1-nyh@scylladb.com>
The gc_grace_seconds is a very fragile and broken design inherited from
Cassandra. Deleted data can be resurrected if cluster wide repair is not
performed within gc_grace_seconds. This design pushes the job of making
the database consistency to the user. In practice, it is very hard to
guarantee repair is performed within gc_grace_seconds all the time. For
example, repair workload has the lowest priority in the system which can
be slowed down by the higher priority workload, so that there is no
guarantee when a repair can finish. A gc_grace_seconds value that is
used to work might not work after data volume grows in a cluster. Users
might want to avoid running repair during a specific period where
latency is the top priority for their business.
To solve this problem, an automatic mechanism to protect data
resurrection is proposed and implemented. The main idea is to remove the
tombstone only after the range that covers the tombstone is repaired.
In this patch, a new table option tombstone_gc is added. The option is
used to configure tombstone gc mode. For example:
1) GC a tombstone after gc_grace_seconds
cqlsh> ALTER TABLE ks.cf WITH tombstone_gc = {'mode':'timeout'} ;
This is the default mode. If no tombstone_gc option is specified by the
user. The old gc_grace_seconds based gc will be used.
2) Never GC a tombstone
cqlsh> ALTER TABLE ks.cf WITH tombstone_gc = {'mode':'disabled'};
3) GC a tombstone immediately
cqlsh> ALTER TABLE ks.cf WITH tombstone_gc = {'mode':'immediate'};
4) GC a tombstone after repair
cqlsh> ALTER TABLE ks.cf WITH tombstone_gc = {'mode':'repair'};
In addition to the 'mode' option, another option 'propagation_delay_in_seconds'
is added. It defines the max time a write could possibly delay before it
eventually arrives at a node.
A new gossip feature TOMBSTONE_GC_OPTIONS is added. The new tombstone_gc
option can only be used after the whole cluster supports the new
feature. A mixed cluster works with no problem.
Tests: compaction_test.py, ninja test
Fixes#3560
[avi: resolve conflicts vs data_dictionary]
"
A big problem with scylla tool executables is that they include the
entire scylla codebase and thus they are just as big as the scylla
executable itself, making them impractical to deploy on production
machines. We could try to combat this by selectively including only the
actually needed dependencies but even ignoring the huge churn of
sorting out our depedency hell (which we should do at one point anyway),
some tools may genuinely depend on most of the scylla codebase.
A better solution is to host the tool executables in the scylla
executable itself, switching between the actual main function to run
some way. The tools themselves don't contain a lot of code so
this won't cause any considerable bloat in the size of the scylla
executable itself.
This series does exactly this, folds all the tool executables into the
scylla one, with main() switching between the actual main it will
delegate to based on a argv[1] command line argument. If this is a known
tool name, the respective tool's main will be invoked.
If it is "server", missing or unrecognized, the scylla main is invoked.
Originally this series used argv[0] as the mean to switch between the
main to run. This approach was abandoned for the approach mentioned above
for the following reasons:
* No launcher script, hard link, soft link or similar games are needed to
launch a specific tool.
* No packaging needed, all tools are automatically deployed.
* Explicit tool selection, no surprises after renaming scylla to
something else.
* Tools are discoverable via scylla's description.
* Follows the trend set by modern command line multi-command or multi-app
programs, like git.
Fixes: #7801
Tests: unit(dev)
"
* 'tools-in-scylla-exec-v5' of https://github.com/denesb/scylla:
main,tools,configure.py: fold tools into scylla exec
tools: prepare for inclusion in scylla's main
main: add skeleton switching code on argv[1]
main: extract scylla specific code into scylla_main()
The infrastructure is now in place. Remove the proxy main of the tools,
and add appropriate `else if` statements to the executable switch in
main.cc. Also remove the tool applications from the `apps` list and add
their respective sources as dependencies to the main scylla executable.
With this, we now have all tool executables living inside the scylla
main one.
The new module will contain all schema related metadata, detached from
actual data access (provided by the database class). User types is the
first contents to be moved to the new module.
It turns out that -O3 enabled -fslp-vectorize even if it is
disabled before -O3 on the command line. Rearrange the code
so that -O3 is before the more specific optimization options.
This PR finally removes the `term` class and replaces it with `expression`.
* There was some trouble with `lwt_cache_id` in `expr::function_call`.
The current code works the following way:
* for each `function_call` inside a `term` that describes a pk restriction, `prepare_context::add_pk_function_call` is called.
* `add_pk_function_call` takes a `::shared_ptr<cql3::functions::function_call>`, sets its `cache_id` and pushes this shared pointer onto a vector of all collected function calls
* Later when some condiition is met we want to clear cache ids of all those collected function calls. To do this we iterate through shared pointers collected in `prepare_context` and clear cache id for each of them.
This doesn't work with `expr::function_call` because it isn't kept inside a shared pointer.
To solve this I put the `lwt_cache_id` inside a shared pointer and then `prepare_context` collects these shared pointers to cache ids.
I also experimented with doing this without any shared pointers, maybe we could just walk through the expression and clear the cache ids ourselves. But the problem is that expressions are copied all the time, we could clear the cache in one place, but forget about a copy. Doing it using shared pointers more closely matches the original behaviour.
The experiment is on the [term2-pr3-backup-altcache](https://github.com/cvybhu/scylla/tree/term2-pr3-backup-altcache) branch
* `shared_ptr<term>` being `nullptr` could mean:
* It represents a cql value `null`
* That there is no value, like `std::nullopt` (for example in `attributes.hh`)
* That it's a mistake, it shouldn't be possible
A good way to distinguish between optional and mistake is to look for `my_term->bind_and_get()`, we then know that it's not an optional value.
* On the other hand `raw_value` cased to bool means:
* `false` - null or unset
* `true` - some value, maybe empty
I ran a simple benchmark on my laptop to see how performance is affected:
```
build/release/test/perf/perf_simple_query --smp 1 -m 1G --operations-per-shard 1000000 --task-quota-ms 10
```
* On master (a21b1fbb2f) I get:
```
176506.60 tps ( 77.0 allocs/op, 12.0 tasks/op, 45831 insns/op)
median 176506.60 tps ( 77.0 allocs/op, 12.0 tasks/op, 45831 insns/op)
median absolute deviation: 0.00
maximum: 176506.60
minimum: 176506.60
```
* On this branch I get:
```
172225.30 tps ( 75.1 allocs/op, 12.1 tasks/op, 46106 insns/op)
median 172225.30 tps ( 75.1 allocs/op, 12.1 tasks/op, 46106 insns/op)
median absolute deviation: 0.00
maximum: 172225.30
minimum: 172225.30
```
Closes#9481
* github.com:scylladb/scylla:
cql3: Remove remaining mentions of term
cql3: Remove term
cql3: Rename prepare_term to prepare_expression
cql3: Make prepare_term return an expression instead of term
cql3: expr: Add size check to evaluate_set
cql3: expr: Add expr::contains_bind_marker
cql3: expr: Rename find_atom to find_binop
cql3: expr: Add find_in_expression
cql3: Remove term in operations
cql3: Remove term in relations
cql3: Remove term in multi_column_restrictions
cql3: Remove term in term_slice, rename to bounds_slice
cql3: expr: Remove term in expression
cql3: expr: Add evaluate_IN_list(expression, options)
cql3: Remove term in column_condition
cql3: Remove term in select_statement
cql3: Remove term in update_statement
cql3: Use internal cql format in insert_prepared_json_statement cache
types: Add map_type_impl::serialize(range of <bytes, bytes>)
cql3: Remove term in cql3/attributes
cql3: expr: Add constant::view() method
cql3: expr: Implement fill_prepare_context(expression)
cql3: expr: add expr::visit that takes a mutable expression
cql3: expr: Add receiver to expr::bind_variable
Operations of adding or removing a node to Raft configuration
are made idempotent: they do nothing if already done, and
they are safe to resume after a failure.
However, since topology changes are not transactional, if a
bootstrap or removal procedure fails midway, Raft group 0
configuration may go out of sync with topology state as seen by
gossip.
In future we must change gossip to avoid making any persistent
changes to the cluster: all changes to persistent topology state
will be done exclusively through Raft Group 0.
Specifically, instead of persisting the tokens by advertising
them through gossip, the bootstrap will commit a change to a system
table using Raft group 0. nodetool will switch from looking at
gossip-managed tables to consulting with Raft Group 0 configuration
or Raft-managed tables.
Once this transformation is done, naturally, adding a node to Raft
configuration (perhaps as a non-voting member at first) will become the
first persistent change to ring state applied when a node joins;
removing a node from the Raft Group 0 configuration will become the last
action when removing a node.
Until this is done, do our best to avoid a cluster state when
a removed node or a node which addition failed is stuck in Raft
configuration, but the node is no longer present in gossip-managed
system tables. In other words, keep the gossip the primary source of
truth. For this purpose, carefully chose the timing when we
join and leave Raft group 0:
Join the Raft group 0 only after we've advertised our tokens, so the
cluster is aware of this node, it's visible in nodetool status,
but before node state jumps to "normal", i.e. before it accepts
queries. Since the operation is idempotent, invoke it on each
restart.
Remove the node from Group 0 *before* its tokens are removed
from gossip-managed system tables. This guarantees
that if removal from Raft group 0 fails for whatever reason,
the node stays in the ring, so nodetool removenode and
friends are re-tried.
Add tracing.
Introduce a special state machine used to to find
a leader of an existing Raft cluster or create
a new cluster.
This state machine should be used when a new
Scylla node has no persisted Raft Group 0 configuration.
The algorithm is initialized with a list of seed
IP addresses, IP address of this server, and,
this server's Raft server id.
The IP addresses are used to construct an initial list of peers.
Then, the algorithm tries to contact each peer (excluding self) from
its peer list and share the peer list with this peer, as well as
get the peer's peer list. If this peer is already part of
some Raft cluster, this information is also shared. On a response
from a peer, the current peer's peer list is updated. The
algorithm stops when all peers have exchanged peer information or
one of the peers responds with id of a Raft group and Raft
server address of the group leader.
(If any of the peers fails to respond, the algorithm re-tries
ad infinitum with a timeout).
More formally, the algorithm stops when one of the following is true:
- it finds an instance with initialized Raft Group 0, with a leader
- all the peers have been contacted, and this server's
Raft server id is the smallest among all contacted peers.
First, it doesn't test the gossiper so
it's unclear why have it at all.
And it doesn't test anything more than what we test
using the cql_test_env either.
For testing gossip there is test/manual/gossip.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Message-Id: <20211122081305.789375-2-bhalevy@scylladb.com>
This PR introduces 4 new virtual tables aimed at replacing nodetool commands, working towards the long-term goal of replacing nodetool completely at least for cluster information retrieval purposes.
As you may have noticed, most of these replacement are not exact matches. This is on purpose. I feel that the nodetool commands are somewhat chaotic: they might have had a clear plan on what command prints what but after years of organic development they are a mess of fields that feel like don't belong. In addition to this, they are centered on C* terminology which often sounds strange or doesn't make any sense for scylla (off-heap memory, counter cache, etc.).
So in this PR I tried to do a few things:
* Drop all fields that don't make sense for scylla;
* Rename/reformat/rephrase fields that have a corresponding concept in scylla, so that it uses the scylla terminology;
* Group information in tables based on some common theme;
With these guidelines in mind lets look at the virtual tables introduced in this PR:
* `system.snapshots` - replacement for `nodetool listnapshots`;
* `system.protocol_servers`- replacement for `nodetool statusbinary` as well as `Thrift active` and `Native Transport active` from `nodetool info`;
* `system.runtime_info` - replacement for `nodetool info`, not an exact match: some fields were removed, some were refactored to make sense for scylla;
* `system.versions` - replacement for `nodetool version`, prints all versions, including build-id;
Closes#9517
* github.com:scylladb/scylla:
test/cql-pytest: add virtual_tables.py
test/cql-pytest: nodetool.py: add take_snapshot()
db/system_keyspace: add versions table
configure.py: move release.cc and build_id.cc to scylla_core
db/system_keyspace: add runtime_info table
db/system_keyspace: add protocol_servers table
service: storage_service: s/client_shutdown_hooks/protocol_servers/
service: storage_service: remove unused unregister_client_shutdown_hook
redis: redis_service: implement the protocol_server interface
alternator: controller: implement the protocol_server interface
transport: controller: implement the protocol_server interface
thrift: controller: implement the protocol_server interface
Add protocol_server interface
db/system_keyspace: add snapshots virtual table
db/virtual_table: remove _db member
db/system_keyspace: propagate distributed<> database and storage_service to register_virtual_tables()
docs/design-notes/system_keyspace.md: add listing of existing virtual tables
docs/guides: add virtual-tables.md
These two files were only added to the scylla executable and some
specific unit tests. As we are about to use the symbols defined in these
files in some scylla_core code move them there.
