Single-row reads from large partition issue 64 KiB reads to the data file,
which is equal to the default span of the promoted index block in the data file.
If users would want to increase selectivity of the index to speed up single-row reads,
this won't be effective. The reason is that the reader uses promoted index
to look up the start position in the data file of the read, but end position
will in practice extend to the next partition, and amount of I/O will be
determined by the underlying file input stream implementation and its
read-ahead heuristics. By default, that results in at least 2 IOs 32KB each.
There is already infrastructure to lookup end position based on upper
bound of the read, in anticipation for sharing the promoted index cache,
but it's not effective becasue it's a non-populating lookup and the upper
bound cursor has its own private cached_promoted_index, which is cold
when positions are computed. It's non-populating on purpose, to avoid
extra index file IO to read upper bound. In case upper bound is far-enough
from the lower bound, this will only increase the cost of the read.
The solution employed here is to warm up the lower bound cursor's
cache before positions are computed, and use that cursor for
non-populating lookup of the upper bound.
We use the lower bound cursor and the slice's lower bound so that we
read the same blocks as later lower-bound slicing would, so that we
don't incur extra IO for cases where looking up upper bound is not
worth it, that is when upper bound is far from the lower bound. If
upper bound is near lower bound, then warming up using lower bound
will populate cached_promoted_index with blocks which will allow us to
locate the upper bound block accurately. This is especially important
for single-row reads, where the bounds are around the same key. In
this case we want to read the data file range which belongs to a
single promoted index block. It doesn't matter that the upper bound
is not exactly the same. They both will likely lie in the same block,
and if not, binary search will bring adjacent blocks into cache. Even
if upper bound is not near, the binary search will populate the cache
with blocks which can be used to narrow down the data file range
somewhat.
Fixes#10030.
The change was tested with perf-fast-forward.
I populated the data set with `column_index_size_in_kb` set to 1
scylla perf-fast-forward --populate --run-tests=large-partition-slicing --column-index-size-in-kb=1
Test run:
build/release/scylla perf-fast-forward --run-tests=large-partition-select-few-rows -c1 --keep-cache-across-test-cases --test-case-duration=0
This test issues two reads of subsequent keys from the middle of a large partition (1M rows in total). The first read will miss in the index file page cache, the second read will hit.
Notice that before the change, the second read issued 2 aio requests worth of 64KiB in total.
After the change, the second read issued 1 aio worth of 2 KiB. That's because promoted index block is larger than 1 KiB.
I verified using logging that the data file range matches a single promoted index block.
Also, the first read which misses in cache is still faster after the change.
Before:
```
running: large-partition-select-few-rows on dataset large-part-ds1
Testing selecting few rows from a large partition:
stride rows time (s) iterations frags frag/s mad f/s max f/s min f/s avg aio aio (KiB) blocked dropped idx hit idx miss idx blk c hit c miss c blk allocs tasks insns/f cpu
500000 1 0.009802 1 1 102 0 102 102 21.0 21 196 2 1 0 1 1 0 0 0 568 269 4716050 53.4%
500001 1 0.000321 1 1 3113 0 3113 3113 2.0 2 64 1 0 1 0 0 0 0 0 116 26 555110 45.0%
```
After:
```
running: large-partition-select-few-rows on dataset large-part-ds1
Testing selecting few rows from a large partition:
stride rows time (s) iterations frags frag/s mad f/s max f/s min f/s avg aio aio (KiB) blocked dropped idx hit idx miss idx blk c hit c miss c blk allocs tasks insns/f cpu
500000 1 0.009609 1 1 104 0 104 104 20.0 20 137 2 1 0 1 1 0 0 0 561 268 4633407 43.1%
500001 1 0.000217 1 1 4602 0 4602 4602 1.0 1 2 1 0 1 0 0 0 0 0 110 26 313882 64.1%
```
Backports: none, not a regression
Closesscylladb/scylladb#20522
* github.com:scylladb/scylladb:
perf: perf_fast_forward: Add test case for querying missing rows
perf-fast-forward: Allow overriding promoted index block size
perf-fast-forward: Test subsequent key reads from the middle in test_large_partition_select_few_rows
perf-fast-forward: Allow adding key offset in test_large_partition_select_few_rows
perf-fast-forward: Use single-partition reads in test_large_partition_select_few_rows
sstables: bsearch_clustered_cursor: Add more tracing points
sstables: reader: Log data file range
sstables: bsearch_clustered_cursor: Unify skip_info logging
sstables: bsearch_clustered_cursor: Narrow down range using "end" position of the block
sstables: bsearch_clustered_cursor: Skip even to the first block
test: sstables: sstable_3_x_test: Improve failure message
sstables: mx: writer: Never include partition_end marker in promoted index block width
sstables: Reduce amount of I/O for clustering-key-bounded reads from large partitions
sstables: clustered_cursor: Track current block
Commit 3a12ad96c7
added an sstable_identifier uuid to the SSTable
scylla_metadata component, however it was
under-documented and this patch adds the missing
documentation for the sstable component format,
and to the scylla sstable tool documentation.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Closesscylladb/scylladb#21221
this commit moves the object storage configuration guide from the developer
documentation to the user-facing admin documentation. the change reflects
the increasing importance of object storage integration in user-facing
features.
in this change:
- move relevant content from `docs/dev/object_storage.md` to
`docs/operating-scylla/admin.rst`
- reformat the content from Markdown to reStructuredText (RST)
- reword and restructure the content to be more user-friendly
- add explanations and context suitable for a broader audience
this change makes the object storage configuration information more
accessible to Scylla administrators and end-users, supporting the adoption
of new features built on top of object storage integration.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Currently, it may happen that the last promoted index block includes
the partition_end marker. That's because we first write the partition
end marker and then emit the unclosed block. This behavior matches
Cassandra (checked in 3.x and 5.0.1).
This is problematic for ruling out data file reads based on index.
The width field is currently unused, but it will be used later where
the width of the last block is used to compute the skip position past
the last block for lookups which land after all keys in the
partition. If width includes the marker then such a skip would land in
the next partition, which is incorrect, as the reader context expects
a cell element. Even if that was recognized, it's wrong - if this is
not a single partition read (so upper bound is not at the next
partition too), then we would read from the wrong (next) partition.
We want to be able to make such skips in order to avoid unnecessary
data file IO for reads of missing rows. Currently, we would always
read the last block even if the key is past its "end" position.
Another way to solve this would be to propagate the "past the last
block" condition from the index cursor to the reader and let it deal
with it, but the logic for that would be complicated. With this fix,
there is no special logic required.
with this parameter, "backup" API can backup the given table, this
enables it to be a drop-in replacement of existing rclone API used by
scylla manager.
Fixes https://github.com/scylladb/scylladb/issues/20636
---
this change is a part of the efforts to bring the native backup/restore to scylla, no need to backprt.
Closesscylladb/scylladb#20661
* github.com:scylladb/scylladb:
backup_task: fix the indent
treewide: add "table" parameter to "backup" API
with this parameter, "backup" API can backup the given table, this
enables it to be a drop-in replacement of existing rclone API used by
scylla manager.
in this change:
* api/storage_service: add "table" parameter to "backup" API.
* snapshot_ctl: compose the full path of the snapshot directory in
`snapshot_ctl::start_backup`. since we have all the information
for composing the snapshot directory, and what the `backup_task_impl`
class is interested is but the snapshot directory, we just pass
the path to it instead the individual components of the directory.
* backup_task_impl: instead of scan the whole keyspace recursively,
only scan the specified snapshot directory.
Fixesscylladb/scylladb#20636
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Auth has been managed via Raft since Scylla 6.0. Restoring data
following the usual procedure (1) is error-prone and so a safer
method must have been designed and implemented. That's what
happens in this PR.
We want to extend `DESC SCHEMA` by auth and service levels
to provide a safe way to backup and restore those two components.
To realize that, we change the meaning of `DESC SCHEMA WITH INTERNALS`
and add a new "tier": `DESC SCHEMA WITH INTERNALS AND PASSWORDS`.
* `DESC SCHEMA` -- no change, i.e. the statement describes the current
schema items such as keyspaces, tables, views, UDTs, etc.
* `DESC SCHEMA WITH INTERNALS` -- does the same as the previous tier
and also describes auth and service levels. No information about
passwords is returned.
* `DESC SCHEMA WITH INTERNALS AND PASSWORDS` -- does the same
as the previous tier and also includes information about the salted
hashes corresponding to the passwords of roles.
To restore existing roles, we extend the `CREATE ROLE` statement
by allowing to use the option `WITH SALTED HASH = '[...]'`.
---
Implementation strategy:
* Add missing things/adjust existing ones that will be used later.
* Implement creating a role with salted hash.
* Add tests for creating a role with salted hash.
* Prepare for implementing describe functionality of auth and service levels.
* Implement describe functionality for elements of auth and service levels.
* Extend the grammar.
* Add tests for describe auth and service levels.
* Add/update documentation.
---
(1): https://opensource.docs.scylladb.com/stable/operating-scylla/procedures/backup-restore/restore.html
In case the link stops working, restoring a schema was realised
by managing raw files on disk.
Fixesscylladb/scylladb#18750Fixesscylladb/scylladb#18751Fixesscylladb/scylladb#20711Closesscylladb/scylladb#20168
* github.com:scylladb/scylladb:
docs: Update user documentation for backup and restore
docs/dev: Add documentation for DESC SCHEMA
test: Add tests for describing auth and service levels
cql3/functions/user_function: Remove newline character before and after UDF body
cql3: Implement DESCRIBE SCHEMA WITH INTERNALS AND PASSWORDS
auth: Implement describing auth
auth/authenticator: Add member functions for querying password hash
service/qos/service_level_controller: Describe service levels
data_dictionary: Remove keyspace_element.hh
treewide: Start using new overloads of describe
treewide: Fix indentation in describe functions
treewide: Return create statement optionally in describe functions
treewide: Add new describe overloads to implementations of data_dictionary::keyspace_element
treewide: Start using schema::ks_name() instead of schema::keyspace_name()
cql3: Refactor `description`
cql3: Move description to dedicated files
test: Add tests for `CREATE ROLE WITH SALTED HASH`
cql3/statements: Restrict CREATE ROLE WITH SALTED HASH
auth: Allow for creating roles with SALTED HASH
types: Introduce a function `cql3_type_name_without_frozen()`
cql3/util: Accept std::string_view rather than const sstring&
We add documentation for developers addressing
`DESCRIBE SCHEMA`. It covers the following aspects
of it:
* motivation,
* synopsis of the solution,
* implementation of the solution,
as well as a few subsections explaining the details:
* restoring process and its side effects,
* restoring roles with passwords,
* list of statements generated by `DESC SCHEMA`
with examples,
* implementation details.
`unspecified` workload type is an internal value and it's not exposed to
user via CQL.
Default value for workload type from user's perspective is `NULL`.
Fixesscylladb/scylladb#20780
* Also dump diagnostics when a read times out while active (not queued).
* Add the "Trigger permit" line, containing the details of the permit which caused the diagnostics dump (by e.g. timing out).
* Add the "Identified bottleneck(s)" line, containing the identified bottlenecks which lead to permits being queued. This line is missing if no such bottleneck can be identified.
* Document the new features, as well as the stat dump, which was added some time ago.
Example of the new dump format:
```
INFO 2024-09-12 08:09:48,046 [shard 0:main] reader_concurrency_semaphore - Semaphore reader_concurrency_semaphore_dump_reader_diganostics with 8/10 count and 106192275/32768 memory resources: timed out, dumping permit diagnostics:
Trigger permit: count=0, memory=0, table=ks.tbl0, operation=mutation-query, state=waiting_for_admission
Identified bottleneck(s): memory
permits count memory table/operation/state
3 2 26M *.*/push-view-updates-2/active
3 2 16M ks.tbl1/push-view-updates-1/active
1 1 15M ks.tbl2/push-view-updates-1/active
1 0 13M ks.tbl1/multishard-mutation-query/active
1 0 12M ks.tbl0/push-view-updates-1/active
1 1 10M ks.tbl3/push-view-updates-2/active
1 1 6060K ks.tbl3/multishard-mutation-query/active
2 1 1930K ks.tbl0/push-view-updates-2/active
1 0 1216K ks.tbl0/multishard-mutation-query/active
6 0 0B ks.tbl1/shard-reader/waiting_for_admission
3 0 0B *.*/data-query/waiting_for_admission
9 0 0B ks.tbl0/mutation-query/waiting_for_admission
2 0 0B ks.tbl2/shard-reader/waiting_for_admission
4 0 0B ks.tbl0/shard-reader/waiting_for_admission
9 0 0B ks.tbl0/data-query/waiting_for_admission
7 0 0B ks.tbl3/mutation-query/waiting_for_admission
5 0 0B ks.tbl1/mutation-query/waiting_for_admission
2 0 0B ks.tbl2/mutation-query/waiting_for_admission
8 0 0B ks.tbl1/data-query/waiting_for_admission
1 0 0B *.*/mutation-query/waiting_for_admission
26 0 0B permits omitted for brevity
96 8 101M total
Stats:
permit_based_evictions: 0
time_based_evictions: 0
inactive_reads: 0
total_successful_reads: 0
total_failed_reads: 0
total_reads_shed_due_to_overload: 0
total_reads_killed_due_to_kill_limit: 0
reads_admitted: 1
reads_enqueued_for_admission: 82
reads_enqueued_for_memory: 0
reads_admitted_immediately: 1
reads_queued_because_ready_list: 0
reads_queued_because_need_cpu_permits: 82
reads_queued_because_memory_resources: 0
reads_queued_because_count_resources: 0
reads_queued_with_eviction: 0
total_permits: 97
current_permits: 96
need_cpu_permits: 0
awaits_permits: 0
disk_reads: 0
sstables_read: 0
```
Fixes: https://github.com/scylladb/scylladb/issues/19535
Improvement, no backport needed.
Closesscylladb/scylladb#20545
* github.com:scylladb/scylladb:
docs/dev/reader-concurrency-semaphore.md: update the documentation on diagnostics dumps
test/boost/reader_concurrency_semaphore_test: test the new diagnostics functionality
reader_concurrency_semaphore: add bottleneck self-diagnosis to diagnosis dump
reader_concurrency_semaphore: include trigger permit in diagnostic dump
reader_concurrency_semaphore: propagate permit to do_dump_reader_permit_diagnostics()
reader_concurrency_semaphore: use consistent exception type for timeout
reader_concurrency_semaphore: dump diagnostics when non-waiting reader times out
When purging regular tombstone consult the min_live_timestamp, if available.
This is safe since we don't need to protect dead data from resurrection, as it is already dead.
For shadowable_tombstones, consult the min_memtable_live_row_marker_timestamp,
if available, otherwise fallback to the min_live_timestamp.
If we see in a view table a shadowable tombstone with time T, then in any row where the row marker's timestamp is higher than T the shadowable tombstone is completely ignored and it doesn't hide any data in any column, so the shadowable tombstone can be safely purged without any effect or risk resurrecting any deleted data.
In other words, rows which might cause problems for purging a shadowable tombstone with time T are rows with row markers older or equal T. So to know if a whole sstable can cause problems for shadowable tombstone of time T, we need to check if the sstable's oldest row marker (and not oldest column) is older or equal T. And the same check applies similarly to the memtable.
If both extended timestamp statistics are missing, fallback to the legacy (and inaccurate) min_timestamp.
Fixesscylladb/scylladb#20423Fixesscylladb/scylladb#20424
> [!NOTE]
> no backport needed at this time
> We may consider backport later on after given some soak time in master/enterprise
> since we do see tombstone accumulation in the field under some materialized views workloads
Closesscylladb/scylladb#20446
* github.com:scylladb/scylladb:
cql-pytest: add test_compaction_tombstone_gc
sstable_compaction_test: add mv_tombstone_purge_test
sstable_compaction_test: tombstone_purge_test: test that old deleted data do not inhibit tombstone garbage collection
sstable_compaction_test: tombstone_purge_test: add testlog debugging
sstable_compaction_test: tombstone_purge_test: make_expiring: use next_timestamp
sstable, compaction: add debug logging for extended min timestamp stats
compaction: get_max_purgeable_timestamp: use memtable and sstable extended timestamp stats
compaction: define max_purgeable_fn
tombstone: can_gc_fn: move declaration to compaction_garbage_collector.hh
sstables: scylla_metadata: add ext_timestamp_stats
compaction_group, storage_group, table_state: add extended timestamp stats getters
sstables, memtable: track live timestamps
memtable_encoding_stats_collector: update row_marker: do nothing if missing
The part of the document which explains diagnostics dumps was due for an
update. It was missing an explanation on the dumped stats and it
also needs to explain the "Problematic permit" and "Identified
bottleneck(s)".
Store and retrieve the optional extended timestamp statistics
(min_live_timestamp and min_live_row_marker_timestamp)
in the scylla_metadata component.
Note that there is no need for a cluster feature to
store those attributes since the scylla_metadata
on-disk format is extensible so that old sstables
can be read by new versions, seeing the extra stats
is missing, and new sstables can be read by old
versions that ignore unknown scylla metadata section types.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Refs #18161
Yet another approach to dealing with large commitlog submissions.
We handle oversize single mutation by adding yet another entry
typo: fragmented. In this case we only add a fragment (aha) of
the data that needs storing into each entry, along with metadata
to correlate and reconstruct the full entry on replay.
Because these fragmented entries are spread over N segments, we
also need to add references from the first segment in a chain
to the subsequent ones. These are released once we clear the
relevant cf_id count in the base.
*
This approach has the downside that due to how serialization etc
works w.r.t. mutations, we need to create an intermediate buffer
to hold the full serialized target entry. This is then incrementally
written into entries of < max_mutation_size, successively requesting
more segments.
On replay, when encountering a fragment chain, the fragment is
added to a "state", i.e. a mapping of currently processing
frag chains. Once we've found all fragments and concatenated
the buffers into a single fragmented one, we can issue a
replay callback as usual.
Note that a replay caller will need to create and provide such
a state object. Old signature replay function remains for tests
and such.
This approach bumps the file format (docs to come).
To ensure "atomicity" we both force synchronization, and should
the whole op fail, we restore segment state (rewinding), thus
discarding data all we wrote.
Closesscylladb/scylladb#19472
* github.com:scylladb/scylladb:
commitlog/database: Make some commitlog options updatable + add feature listener
features/config: Add feature for fragmented commitlog entries
docs: Add entry on commitlog file format v4
commitlog_test: Add more oversized cases
commitlog_replayer: Replay segments in order created
commitlog_replayer: Use replay state to support fragmented entries
commitlog_replayer: coroutinize partly
commitlog: Handle oversized entries
~~~
What we have today in "docs/dev/docker-hub.md" on "aio-max-nr" dates back
to scylla commit f4412029f4 ("docs/docker-hub.md: add quickstart section
with --smp 1", 2020-09-22). Problems with the current language:
- The "65K" claim as default value on non-production systems is wrong;
"fs/aio.c" in Linux initializes "aio_max_nr" to 0x10000, which is 64K.
- The section in question uses equal signs (=) incorrectly. The intent was
probably to say "which means the same as", but that's not what equality
means.
- In the same section, the relational operator "<" is bogus. The available
AIO count must be at least as high (>=) as the requested AIO count.
- Clearer names should be used;
adjust_max_networking_aio_io_control_blocks() in "src/core/reactor.cc"
sets a great example:
- "reactor::max_aio" should be called "storage_iocbs",
- "detect_aio_poll" should be called "preempt_iocbs",
- "reactor_backend_aio::max_polls" should be called "network_iocbs".
- The specific value 10000 for the last one ("network_iocbs") is not
correct in scylla's context. It is correct as the Seastar default, but
scylla has used 50000 since commit 2cfc517874 ("main, test: adjust
number of networking iocbs", 2021-07-18).
Rewrite the section to address these problems.
See also:
- https://github.com/scylladb/scylladb/issues/5981
- https://github.com/scylladb/seastar/pull/2396
- https://github.com/scylladb/scylladb/pull/19921
Signed-off-by: Laszlo Ersek <laszlo.ersek@scylladb.com>
~~~
No need for backporting; the documentation being refreshed targets developers as audience, not end-users.
Closesscylladb/scylladb#20398
* github.com:scylladb/scylladb:
docs/dev/docker-hub.md: refresh aio-max-nr calculation
docs/dev/docker-hub.md: strip trailing whitespace
Before the introduction of "scripts/refresh-submodules.sh", there was
indeed some manual work for the maintainer to do, hence "publish your
work" must have sounded correct. Today, the phrase "publish your work"
sounds confusing.
Commit 71da4e6e79 ("docs: Document sync-submodules.sh script in
maintainer.md", 2020-06-18) should have arguably reworded the last step of
the submodule refresh procedure; let's do it now.
Signed-off-by: Laszlo Ersek <laszlo.ersek@scylladb.com>
Closesscylladb/scylladb#20333
What we have today in "docs/dev/docker-hub.md" on "aio-max-nr" dates back
to scylla commit f4412029f4 ("docs/docker-hub.md: add quickstart section
with --smp 1", 2020-09-22). Problems with the current language:
- The "65K" claim as default value on non-production systems is wrong;
"fs/aio.c" in Linux initializes "aio_max_nr" to 0x10000, which is 64K.
- The section in question uses equal signs (=) incorrectly. The intent was
probably to say "which means the same as", but that's not what equality
means.
- In the same section, the relational operator "<" is bogus. The available
AIO count must be at least as high (>=) as the requested AIO count.
- Clearer names should be used;
adjust_max_networking_aio_io_control_blocks() in "src/core/reactor.cc"
sets a great example:
- "reactor::max_aio" should be called "storage_iocbs",
- "detect_aio_poll" should be called "preempt_iocbs",
- "reactor_backend_aio::max_polls" should be called "network_iocbs".
- The specific value 10000 for the last one ("network_iocbs") is not
correct in scylla's context. It is correct as the Seastar default, but
scylla has used 50000 since commit 2cfc517874 ("main, test: adjust
number of networking iocbs", 2021-07-18).
Rewrite the section to address these problems.
See also:
- https://github.com/scylladb/scylladb/issues/5981
- https://github.com/scylladb/seastar/pull/2396
- https://github.com/scylladb/scylladb/pull/19921
Signed-off-by: Laszlo Ersek <laszlo.ersek@scylladb.com>
* in the "Backporting Seastar commits" section, there's a single quote
instead of a backtick in this line, so fix it.
* add backticks around `refresh-submodules.sh`, which is a filename.
* correct the command line setting a git config option, because `git-config`
does not support this command line syntax,
```console
$ git config --global diff.conflictstyle = diff3
$ git config --global get diff.conflictstyle
=
$ git config --global diff.conflictstyle diff3
$ git config --global get diff.conflictstyle
diff3
```
quote from git-config(1)
> ```
> git config set [<file-option>] [--type=<type>] [--all] [--value=<value>] [--fixed-value] <name> <value>
> ```
* stop using the deprecated mode of the `git-config` command, and use
subcommand instead. as git-config(1) puts:
> git config <name> <value> [<value-pattern>]
> Replaced by git config set [--value=<pattern>] <name> <value>.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#20328
Currently the doc assumes that object storage can only be used to keep
sstables on it. It's going to change, restructure the doc to allow for
more usage scenarios.
When debugging coredumps some (small, but useful) information is hidden
in the notes of the core ELF file. Add some words about it exists, what
it includes and the thing that is always forgotten -- the way to get one
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Closesscylladb/scylladb#19962
forward_service is nondescriptive and misnamed, as it does more than
forward requests. It's a classic map/reduce algorithm (and in fact one
of its parameters is "reducer"), so name it accordingly.
The name "forward" leaked into the wire protocol for the messaging
service RPC isolation cookie, so it's kept there. It's also maintained
in the name of the logger (for "nodetool setlogginglevel") for
compatibility with tests.
Closesscylladb/scylladb#19444
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
thrift support was deprecated since ScyllaDB 5.2
> Thrift API - legacy ScyllaDB (and Apache Cassandra) API is
> deprecated and will be removed in followup release. Thrift has
> been disabled by default.
so let's drop it. in this change,
* thrift protocol support is dropped
* all references to thrift support in document are dropped
* the "thrift_version" column in system.local table is
preserved for backward compatibility, as we could load
from an existing system.local table which still contains
this clolumn, so we need to write this column as well.
* "/storage_service/rpc_server" is only preserved for
backward compatibility with java-based nodetool.
* `rpc_port` and `start_rpc` options are preserved, but
they are marked as "Unused". so that the new release
of scylladb can consume existing scylla.yaml configurations
which might contain these settings. by making them
deprecated, user will be able get warned, and update
their configurations before we actually remove them
in the next major release.
Fixes#3811Fixes#18416
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
This change supports changing replication factor in tablets-enabled keyspaces.
This covers both increasing and decreasing the number of tablets replicas through
first building topology mutations (`alter_keyspace_statement.cc`) and then
tablets/topology/schema mutations (`topology_coordinator.cc`).
For the limitations of the current solution, please see the docs changes attached to this PR.
Fixes: #16129Closesscylladb/scylladb#16723
* github.com:scylladb/scylladb:
test: Do not check tablets mutations on nodes that don't have them
test: Fix the way tablets RF-change test parses mutation_fragments
test/tablets: Unmark RF-changing test with xfail
docs: document ALTER KEYSPACE with tablets
Return response only when tablets are reallocated
cql-pytest: Verify RF is changes by at most 1 when tablets on
cql3/alter_keyspace_statement: Do not allow for change of RF by more than 1
Reject ALTER with 'replication_factor' tag
Implement ALTER tablets KEYSPACE statement support
Parameterize migration_manager::announce by type to allow executing different raft commands
Introduce TABLET_KEYSPACE event to differentiate processing path of a vnode vs tablets ks
Extend system.topology with 3 new columns to store data required to process alter ks global topo req
Allow query_processor to check if global topo queue is empty
Introduce new global topo `keyspace_rf_change` req
New raft cmd for both schema & topo changes
Add storage service to query processor
tablets: tests for adding/removing replicas
tablet_allocator: make load_balancer_stats_manager configurable by name
Because ALTER KS will result in creating a global topo req, we'll have
to pass the req data to topology coordinator's state machine, and the
easiest way to do it is through sytem.topology table, which is going to
be extended with 3 extra columns carrying all the data required to
execute ALTER KS from within topology coordinator.
Separate keyspace which also behaves as system brings
little benefit while creating some compatibility problems
like schema digest mismatch during rollback. So we decided
to move auth tables into system keyspace.
Fixes https://github.com/scylladb/scylladb/issues/18098Closesscylladb/scylladb#18769
Update `docs/dev/isolation.d`:
* Update the list of scheduling groups
* Remove IO priority groups (they were folded into scheduling groups)
* Add section on RPC isolation
Closesscylladb/scylladb#18749
* github.com:scylladb/scylladb:
docs: isolation.md: add section on RPC call isolation
docs: isolation.md: remove mention of IO priority groups
docs: isolation.md: update scheduling group list, add aliases
There's a nasty scenario when this searching plays bad joke.
When CI picks up a new branch and notices, that a test had changed, it
spawns a custom job with test.py --repeat 100 $changed_test_name in
it. Next, when the test.py tries opt-in test name matching, it uses the
wildcard search and can pick up extra unwanted tests into the run.
To solve this, the case-selection syntax is extended. Now if the caller
specifies `suite/test::*` as test, the test file is selected by exact
name match, but the specific test-case is not selected, the `*` makes it
run all cases.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Closesscylladb/scylladb#18704
Require users to specify whether we want shard for reads or for writes
by switching to appropriate non-deprecated variant.
For example, shard_of() can be replaced with shard_for_reads() or
shard_for_writes().
The next_shard/token_for_next_shard APIs have only for-reads variant,
and the act of switching will be a testimony to the fact that the code
is valid for intra-node migration.
Tablet sharder is adjusted to handle intra-migration where a tablet
can have two replicas on the same host. For reads, sharder uses the
read selector to resolve the conflict. For writes, the write selector
is used.
The old shard_of() API is kept to represent shard for reads, and new
method is introduced to query the shards for writing:
shard_for_writes(). All writers should be switched to that API, which
is not done in this patch yet.
The request handler on replica side acts as a second-level
coordinator, using sharder to determine routing to shards. A given
sharder has a scope of a single topology version, a single
effective_replication_map_ptr, which should be kept alive during
writes.
