assert() is traditionally disabled in release builds, but not in
scylladb. This hasn't caused problems so far, but the latest abseil
release includes a commit [1] that causes a 1000 insn/op regression when
NDEBUG is not defined.
Clearly, we must move towards a build system where NDEBUG is defined in
release builds. But we can't just define it blindly without vetting
all the assert() calls, as some were written with the expectation that
they are enabled in release mode.
To solve the conundrum, change all assert() calls to a new SCYLLA_ASSERT()
macro in utils/assert.hh. This macro is always defined and is not conditional
on NDEBUG, so we can later (after vetting Seastar) enable NDEBUG in release
mode.
[1] 66ef711d68Closesscylladb/scylladb#20006
flat_mutation_reader_v2 was introduced in a pair of commits in 2021:
e3309322c3 "Clone flat_mutation_reader related classes into v2 variants"
08b5773c12 "Adapt flat_mutation_reader_v2 to the new version of the API"
as a replacement for flat_mutation_reader, using range_tombstone_change
instead of range_tombstone to represent represent range tombstones. See
those commits for more information.
The transition was incremental; the last use of the original
flat_mutation_reader was removed in 2022 in commit
026f8cc1e7 "db: Use mutation_partition_v2 in mvcc"
In turn, flat_mutation_reader was introduced in 2017 in commit
748205ca75 "Introduce flat_mutation_reader"
To transition from a mutation_reader that nested rows within
a partition in a separate stream, to a flat reader that streamed
partitions and rows in the same stream.
Here, we reclaim the original name and rename the awkward
flat_mutation_reader_v2 to mutation_reader.
Note that mutation_fragment_v2 remains since we still use the original
for compatibilty, sometimes.
Some notes about the transition:
- files were also renamed. In one case (flat_mutation_reader_test.cc), the
rename target already existed, so we rename to
mutation_reader_another_test.cc.
- a namespace 'mutation_reader' with two definitions existed (in
mutation_reader_fwd.hh). Its contents was folded into the mutation_reader
class. As a result, a few #includes had to be adjusted.
Closesscylladb/scylladb#19356
The inject_with_handler() method accepts a coroutine that can be called
wiht injection_handler. With such function as an argument, there's no
need in distinctive inject_with_handler() name for a method, it can be
overload of all the existing inject()-s
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
The new rpc::optional parameter must come after any existing parameters,
including the rpc::source parameters, otherwise it will break
compatibility.
The regression was introduced in:
```
commit fd3c089ccc
Author: Tomasz Grabiec <tgrabiec@scylladb.com>
Date: Thu Oct 26 00:35:19 2023 +0200
service: range_streamer: Propagate topology_guard to receivers
```
We need to backport this patch ASAP before we release anything that
contains commit fd3c089ccc.
Refs: #16941Fixes: #17175Closesscylladb/scylladb#17176
get0() dates back from the days where Seastar futures carried tuples, and
get0() was a way to get the first (and usually only) element. Now
it's a distraction, and Seastar is likely to deprecate and remove it.
Replace with seastar::future::get(), which does the same thing.
Tablet streaming involves asynchronous RPCs to other replicas which transfer writes. We want side-effects from streaming only within the migration stage in which the streaming was started. This is currently not guaranteed on failure. When streaming master fails (e.g. due to RPC failing), it can be that some streaming work is still alive somewhere (e.g. RPC on wire) and will have side-effects at some point later.
This PR implements tracking of all operations involved in streaming which may have side-effects, which allows the topology change coordinator to fence them and wait for them to complete if they were already admitted.
The tracking and fencing is implemented by using global "sessions", created for streaming of a single tablet. Session is globally identified by UUID. The identifier is assigned by the topology change coordinator, and stored in system.tablets. Sessions are created and closed based on group0 state (tablet metadata) by the barrier command sent to each replica, which we already do on transitions between stages. Also, each barrier waits for sessions which have been closed to be drained.
The barrier is blocked only if there is some session with work which was left behind by unsuccessful streaming. In which case it should not be blocked for long, because streaming process checks often if the guard was left behind and stops if it was.
This mechanism of tracking is fault-tolerant: session id is stored in group0, so coordinator can make progress on failover. The barriers guarantee that session exists on all replicas, and that it will be closed on all replicas.
Closesscylladb/scylladb#15847
* github.com:scylladb/scylladb:
test: tablets: Add test for failed streaming being fenced away
error_injection: Introduce poll_for_message()
error_injection: Make is_enabled() public
api: Add API to kill connection to a particular host
range_streamer: Do not block topology change barriers around streaming
range_streamer, tablets: Do not keep token metadata around streaming
tablets: Fail gracefully when migrating tablet has no pending replica
storage_service, api: Add API to disable tablet balancing
storage_service, api: Add API to migrate a tablet
storage_service, raft topology: Run streaming under session topology guard
storage_service, tablets: Use session to guard tablet streaming
tablets: Add per-tablet session id field to tablet metadata
service: range_streamer: Propagate topology_guard to receivers
streaming: Always close the rpc::sink
storage_service: Introduce concept of a topology_guard
storage_service: Introduce session concept
tablets: Fix topology_metadata_guard holding on to the old erm
docs: Document the topology_guard mechanism
Streaming was keeping effective_replication_map_ptr around the whole
process, which blocks topology change barriers.
This will inhibit progress of tablet load balancer or concurrent
migrations, resulting in worse performance.
Fix by switching to the most recent erm on sharder
calls. multishard_writer calls shard_of() for each new partition.
A better way would be to switch immediately when topology version
changes, but this is left for later.
rpc::sink::~sink aborts if not closed. There is a try/catch clause
which ensures that close() is called, but there was code after sink is
created which is not covered by it. Move sink construction past that
code.
It is possible the sender and receiver of streaming nodes have different
views on if a table is dropped or not.
For example:
- n1, n2 and n3 in the cluster
- n4 started to join the cluster and stream data from n1, n2, n3
- a table was dropped
- n4 failed to write data from n2 to sstable because a table was dropped
- n4 ended the streaming
- n2 checked if the table was present and would ignore the error if the table was dropped
- however n2 found the table was still present and was not dropped
- n2 marked the streaming as failed
This will fail the streaming when a table is dropped. We want streaming to
ignore such dropped tables.
In this patch, a status code is sent back to the sender to notify the
table is dropped so the sender could ignore the dropped table.
Fixes#15370Closesscylladb/scylladb#15912
Handler of STREAM_MUTATION_FRAGMENTS verb creates and starts reader. The
resulting future is then checked for being exceptional and an error
message is printed in logs.
However, if reader fails because of socket being closed by peer, the
error looks excessive. In that case the exception is just regular
handling of the socket/stream closure and can be demoted down to debug
level.
fixes: #15891
Similar cherry-picking of log level exists in e.g. storage proxy, see
for example 56bd9b5d (service: storage_proxy: do not report abort
requests in handle_write )
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Closesscylladb/scylladb#15892
Maps related to column families in database are extracted
to a column_families_data class. Access to them is possible only
through methods. All methods which may preempt hold rwlock
in relevant mode, so that the iterators can't become invalid.
Fixes: #13290Closes#13349
* github.com:scylladb/scylladb:
replica: make tables_metadata's attributes private
replica: add methods to get a filtered copy of tables map
replica: add methods to check if given table exists
replica: add methods to get table or table id
replica: api: return table_id instead of const table_id&
replica: iterate safely over tables related maps
replica: pass tables_metadata to phased_barrier_top_10_counts
replica: add methods to safely add and remove table
replica: wrap column families related maps into tables_metadata
replica: futurize database::add_column_family and database::remove
As a preparation for ensuring access safety for column families
related maps, add tables_metadata, access to members of which
would be protected by rwlock.
In that level no io_priority_class-es exist. Instead, all the IO happens
in the context of current sched-group. File API no longer accepts prio
class argument (and makes io_intent arg mandatory to impls).
So the change consists of
- removing all usage of io_priority_class
- patching file_impl's inheritants to updated API
- priority manager goes away altogether
- IO bandwidth update is performed on respective sched group
- tune-up scylla-gdb.py io_queues command
The first change is huge and was made semi-autimatically by:
- grep io_priority_class | default_priority_class
- remove all calls, found methods' args and class' fields
Patching file_impl-s is smaller, but also mechanical:
- replace io_priority_class& argument with io_intent* one
- pass intent to lower file (if applicatble)
Dropping the priority manager is:
- git-rm .cc and .hh
- sed out all the #include-s
- fix configure.py and cmakefile
The scylla-gdb.py update is a bit hairry -- it needs to use task queues
list for IO classes names and shares, but to detect it should it checks
for the "commitlog" group is present.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Closes#13963
Now which schema pull may issues raft read barrier it may stuck if
majority is not available. Make the operation abortable and abort it
during queries if timeout is reached.
And propagate it down to where it is created. This will be used to add
trace points for semaphore related events, but this will come in the
next patches.
The initial intent was to reduce the fanout of shared_sstable.hh through
v.u.g.hh -> cql_test_env.hh chain, but it also resulted in some shots
around v.u.g.hh -> database.hh inclusion.
By and large:
- v.u.g.hh doesn't need database.hh
- cql_test_env.hh doesn't need v.u.g.hh (and thus -- the
shared_sstable.hh) but needs database.hh instead
- few other .cc files need v.u.g.hh directly as they pulled it via
cql_test_env.hh before
- add forward declarations in few other places
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Closes#12952
these warnings are found by Clang-17 after removing
`-Wno-unused-lambda-capture` and '-Wno-unused-variable' from
the list of disabled warnings in `configure.py`.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Schema related files are moved there. This excludes schema files that
also interact with mutations, because the mutation module depends on
the schema. Those files will have to go into a separate module.
Closes#12858
Move mutation-related files to a new mutation/ directory. The names
are kept in the global namespace to reduce churn; the names are
unambiguous in any case.
mutation_reader remains in the readers/ module.
mutation_partition_v2.cc was missing from CMakeLists.txt; it's added in this
patch.
This is a step forward towards librarization or modularization of the
source base.
Closes#12788
This patch enables offstrategy compaction for all classic streaming
based node ops. We can use this method because tables are streamed one
after another. As long as there is still streamed data for a given
table, we update the automatic trigger timer. When all the streaming has
finished, the trigger timer will timeout and fire the offstrategy
compaction for the given table.
I checked with this patch, rebuild is 3X faster. There was no compaction
in the middle of the streaming. The streamed sstables are compacted
together after streaming is done.
Time Before:
INFO 2022-11-25 10:06:08,213 [shard 0] range_streamer - Rebuild
succeeded, took 67 seconds, nr_ranges_remaining=0
Time After:
INFO 2022-11-25 09:42:50,943 [shard 0] range_streamer - Rebuild
succeeded, took 23 seconds, nr_ranges_remaining=0
Compaciton Before:
88 sstables were written -> 88 sstables were added into main set
Compaction After:
88 sstables written -> after offstretegy 2 sstables were added into main seet
Closes#11848
Define table_schema_version as a distinct tagged_uuid class,
So it can be differentiated from other uuid-class types,
in particular table_id.
Added reversed(table_schema_version) for convenience
and uniformity since the same logic is currently open coded
in several places.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Define table_id as a distinct utils::tagged_uuid modeled after raft
tagged_id, so it can be differentiated from other uuid-class types,
in particular from table_schema_version.
Fixes#11207
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Currently, if a table is dropped during streaming, the streaming would
fail with no_such_column_family error.
Since the table is dropped anyway, it makes more sense to ignore the
streaming result of the dropped table, whether it is successful or
failed.
This allows users to drop tables during node operations, e.g., bootstrap
or decommission a node.
This is especially useful for the cloud users where it is hard to
coordinate between a node operation by admin and user cql change.
This patch also fixes a possible user after free issue by not passing
the table reference object around.
Fixes#10395Closes#10396
In most files it was unused. We should move these to the patch which
moved out the last interesting reader from mutation_reader.hh (and added
the corresponding new header include) but its probably not worth the
effort.
Some other files still relied on mutation_reader.hh to provide reader
concurrency semaphore and some other misc reader related definitions.
std::function<> requires the functor it wraps to be copyable, which is
an unnecessarily strict requirement. To relax this, we use
noncopyable_function<> instead. Since the former seems to lack some
disambiguation magic of the latter, we add `_v1` and `_v2` postfixes to
manually disambiguate.
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
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
Move replica-oriented classes to the replica namespace. The main
classes moved are ::database, ::keyspace, and ::table, but a few
ancillary classes are also moved. There are certainly classes that
should be moved but aren't (like distributed_loader) but we have
to start somewhere.
References are adjusted treewide. In many cases, it is obvious that
a call site should not access the replica (but the data_dictionary
instead), but that is left for separate work.
scylla-gdb.py is adjusted to look for both the new and old names.
When the stream_session initializes it's being equipped with
the shared-pointer on the stream_result_future very early. In
all the places where stream_session needs the manager this
pointer is alive and session get get manager from it.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
