We are having many issues with the stop code in the compaction_manager.
Part of the reason is that the "stopped" state has its meaning overloaded
to indicate both "compaction manager is not accepting compactions" and
"compaction manager is not ready or destructed".
In a later step we could default to enabled-at-start, but right now we
maintain current behavior to minimize noise.
It is only possible to stop the compaction manager once.
It is possible to enable / disable the compaction manager many times.
Signed-off-by: Glauber Costa <glauber@scylladb.com>
We shouldn't assume the I/O priority class for compactions. For
instance, if we are dealing with offstrategy compactions we may want to
use the maintenance group priority for them.
For now, all compactions are put in the compaction class. rewrite
compactions (scrub, cleanup) could be maintenance, but we don't have
clear access to the database object at this time to derive the
equivalent CPU priority. This is planned to be changed in the future,
and when we do change it, we'll adjust.
Same goes for resharding: while we could at this point change it we'd
risking memory pressure since resharding is run online and sstables are
shared until resharding is done. When we move it to offline execution
we'll do it with maintenance priority.
Signed-off-by: Glauber Costa <glauber@scylladb.com>
Message-Id: <20200512002233.306538-3-glauber@scylladb.com>
Input SSTables of resharding is deleted at the coordinator shard, not at the
shards they belong to.
We're not acquiring deletion semaphore before removing those input SSTables
from the SSTable set, so it could happen that resharding deletes those
SSTables while another operation like snapshot, which acquires the semaphore,
find them deleted.
Let's acquire the deletion semaphore so that the input SSTables will only
be removed from the set, when we're certain that nobody is relying on their
existence anymore.
Now resharding will only delete input SStables after they're safely removed
from the SSTable set of all shards they belong to.
unit: test(dev).
Fixes#6328.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Message-Id: <20200507233636.92104-1-raphaelsc@scylladb.com>
Fixes#6202
Distributed loader sstable opening is gated through the
database::sstable_load_concurrency_sem() semaphore
(at a concurrency of 3).
This is (according to creation comment) to reduce memory footprint
during bootstrap, by partially serializing the actual opening of
existing sstables.
However, in certain versions of the product, there exist circular
dependencies between data in some sstables and the ability to actually
read others. Thus when gated as above, we can end up with the
dependents acquiring the semaphore fully, and once stuck waiting for
population of their dependency effectively blocking this from ever
happening.
Since we probably do not want to remove the concurrency control,
and increasing it would only push the problem further away,
we solve the issue by adding the ability to mark certain keyspaces
as "prioritized" (pre-bootstrap), and allow them to populate outside
the normal concurrency control semaphore. Concurrency increase is
however limited to one extra sstable per shard and prio keyspace.
Message-Id: <20200415102431.20816-1-calle@scylladb.com>
There is a method, reshard_sstables(), whose sole purpose is to call a
resharding compaction. There is nothing special about this method: all
the information it needs is now present in the compaction_descriptor.
This patch extend the compaction_options class to recognize resharding
compactions as well, and uses that so that make_compaction() can also
create resharding compactions.
To make that happen we have to create a compaction_descriptor object in
the resharding method. Note however that resharding works by passing an
object very close to the compaction_descriptor around. Once this patch
is merged, a logical next step is to reuse it, and avoid creating the
descriptor right before calling compact_sstables().
Signed-off-by: Glauber Costa <glauber@scylladb.com>
The global get_highest_supported_format helper and its declaration
are scattered all over the code, so clean this up and prepare the
ground for moving _sstables_format from the storage_service onto
the sstables_manager (not this set).
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Allows caller to check/wait for a given user keyspace to finish
populating on boot.
Can be called at any time, though if called before population
starts, it will wait until it either starts and we can determine
that the keyspace does not need populating, or population finishes.
tests: unit
Message-Id: <20200203151712.10003-1-calle@scylladb.com>
This is the last place where database code needs the migration_manager
instance to be alive, so now the mutual dependency between these two
is gone, only the migration_manager needs the database, but not the
vice-versa.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
distributed_loader::probe_file needlessly creates a seastar
thread for it and the next patch will use it as part of
a parallel_for_each loop to move a list of sstables
(and sync the directories once at the end).
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Resharding is responsible for the scheduling the deletion of sstables
resharded, but it was not refreshing the cache of the shards those
sstables belong to, which means cache was incorrectly holding reference
to them even after they were deleted. The consequence is sstables
deleted by resharding not having their disk space freed until cache
is refreshed by a subsequent procedure that triggers it.
Fixes#5261.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Message-Id: <20191107193550.7860-1-raphaelsc@scylladb.com>
Before this change, when populating non-system keyspaces, each data
directory was scanned and for each entry (keyspace directory),
a keyspace was populated. This was done in a serial fashion - populating
of one keyspace was not started until the previous one was done.
Loading keyspaces in such fashion can introduce unnecessary waiting
in case of a large number of keyspaces in one data directory. Population
process is I/O intensive and barely uses CPU.
This change enables parallel loading of keyspaces per data directory.
Populating the next keyspace does not wait for the previous one.
A benchmark was performed measuring startup time, with the following
setup:
- 1 data directory,
- 200 keyspaces,
- 2 tables in each keyspace, with the following schema:
CREATE TABLE tbl (a int, b int, c int, PRIMARY KEY(a, b))
WITH CLUSTERING ORDER BY (b DESC),
- 1024 rows in each table, with values (i, 2*i, 3*i) for i in 0..1023,
- ran on 6-core virtual machine running on i7-8750H CPU,
- compiled in dev mode,
- parameters: --smp 6 --max-io-requests 4 --developer-mode=yes
--datadir $DIR --commitlog-directory $DIR
--hints-directory $DIR --view-hints-directory $DIR
The benchmark tested:
- boot time, by comparing timestamp of the first message in log,
and timestamp of the following message:
"init - Scylla version ... initialization completed."
- keyspace population time, by comparing timestamps of messages:
"init - loading non-system sstables"
and
"init - starting view update generator"
The benchmark was run 5 times for sequential and parallel version,
with the following results:
- sequential: boot 31.620s, keyspace population 6.051s
- parallel: boot 29.966s, keyspace population 4.360s
Keyspace population time decreased by ~27.95%, and overall boot time
by about ~5.23%.
Tests: unit(release)
Fixes#2007
This patches silences the remaining discarded future warnings, those
where it cannot be determined with reasonable confidence that this was
indeed the actual intent of the author, or that the discarding of the
future could lead to problems. For all those places a FIXME is added,
with the intent that these will be soon followed-up with an actual fix.
I deliberately haven't fixed any of these, even if the fix seems
trivial. It is too easy to overlook a bad fix mixed in with so many
mechanical changes.
This patch silences those future discard warnings where it is clear that
discarding the future was actually the intent of the original author,
*and* they did the necessary precautions (handling errors). The patch
also adds some trivial error handling (logging the error) in some
places, which were lacking this, but otherwise look ok. No functional
changes.
During startup, we check that the data files are owned by our euid.
But in a container environment, this is impossible to enforce because
uid/username mappings are different between the host and the container,
and the data files are likely to be mounted from the host.
To allow for such environments, relax the checks if euid=0. This
both matches what happens in a container (programs run as root) and
the kernel access checks (euid 0 can do anything).
We can reconsider this when container uid mapping is better developed.
Fixes#4823.
Fixes#4536.
lister::rmdir has two in-tree users: clearing snapshots and clearing
temporary directories during sstable creation. The way it is currently
coded, it wraps the io functions in io_check, which means that failures
to remove the directory will crash the database.
We recently saw how benign failures crashed a database during
clearsnapshot: we had snapshot creation running in parallel, adding more
files to the directory that wasn't empty by the time of deletion. I
have also seen very often users add files to existing directories by
accident, which is another possibility to trigger that.
This patch removes the io_check from lister, and moves it to the caller
in which we want to be more strict. We still want to be strict about
the creation of temporary directories, since users shouldn't be touching
that in any way.
Fixes#4558
Signed-off-by: Glauber Costa <glauber@scylladb.com>
To prepare for a seastar change that adds an optional file_permissions
parameter to touch_directory and recursive_touch_directory.
This change messes up the call to io_check since the compiler can't
derive the Func&& argument. Therefore, use a lambda function instead
to wrap the call to {recursive_,}touch_directory.
Ref #4395
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Message-Id: <20190421085502.24729-1-bhalevy@scylladb.com>
ignore_ready_future in load_new_ss_tables broke
migration_test:TestMigration_with_*.migrate_sstable_with_counter_test_expect_fail dtests.
The java.io.NotSerializableException in nodetool was caused by exceptions that
were too long.
This fix prints the problematic file names onto the node system log
and includes the casue in the resulting exception so to provide the user
with information about the nature of the error.
Fixes#4375
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Message-Id: <20190331154006.12808-1-bhalevy@scylladb.com>
Files and directories must be owned by the process uid.
Files must have read access and directories must have
read, write, and execute access.
Refs #3117
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
In most cases we make a sstable based on the table schema
and soon - large_data_handler.
Encapsulate that in a make_sstable method.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
When loading tables uploaded via `nodetool refresh`, they used to be
left in upload/ directory if view updates would need to be generated
from them. Since view update generation is asynchronous, sstables
left in the directory could erroneously get overwritten by the user,
who decides to upload another batch of sstables and some of the names
collided.
To remedy this, uploaded sstables that need view updates are moved
to staging/ directory with a unique generation number, where they
await view update generation.
Fixes#4047
table::load_sstable: fix missing arg in old format counters exception
Properly catch and log the exception in load_new_sstables.
Abort when the exception is caught to keep current behavior.
Seen with migration_test:TestMigration_with_2_1_x.migrate_sstable_with_counter_test
without enable_dangerous_direct_import_of_cassandra_counters.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Message-Id: <20190301091235.2914-1-bhalevy@scylladb.com>
Scan the table's pending_delete sub-directory if it exists.
Remove any temporary pending_delete log files to roll back the respective
delete_atomically operation.
Replay completed pending_delete log files to roll forward the respective
delete_atomically operation, and finally delete the log files.
Cleanup of temporary sstable directories and pending_delete
sstables are done in a preliminary scan phase when populating the column family
so that we won't attempt to load the to-be-deleted sstables.
Fixes#4082
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
In preparation for replaying pending_delete log files,
we would like to first remove any temporary sst dirs
and later handle pending_delete log files, and only
then populate the column family.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Right now Cassandra SSTables with counters cannot be imported into
Scylla. The reason for that is that Cassandra changed their counter
representation in their 2.1 version and kept transparently supporting
both representations. We do not support their old representation, nor
there is a sane way to figure out by looking at the data which one is in
use.
For safety, we had made the decision long ago to not import any
tables with counters: if a counter was generated in older Cassandra, we
would misrepresent them.
In this patch, I propose we offer a non-default way to import SSTables
with counters: we can gate it with a flag, and trust that the user knows
what they are doing when flipping it (at their own peril). Cassandra 2.1
is by now pretty old. many users can safely say they've never used
anything older.
While there are tools like sstableloader that can be used to import
those counters, there are often situations in which directly importing
SSTables is either better, faster, or worse: the only option left. I
argue that having a flag that allow us to import them when we are sure
it is safe is better than having no option at all.
With this patch I was able to successfully import Cassandra tables with
counters that were generated in Cassandra 2.1, reshard and compact their
SSTables, and read the data back to get the same values in Scylla as in
Cassandra.
Signed-off-by: Glauber Costa <glauber@scylladb.com>
Message-Id: <20190210154028.12472-1-glauber@scylladb.com>
1. fs::canonical required that the path will exist.
and there is no need for fs::canonical here.
2. fs::path::extension will return the leading dot.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
populate_column_family currently lists only regular files. ignoring all directories.
A later patch in this series allows it to list also directories so to cleanup
the temporary sstable directories, yet valid sub-directories, like staging|upload|snapshots,
may still exist and need to be ignored.
Other kinds of handling, like validating recgnized sub-directories and halting on
unrecognized sub-directories are possible, yet out of scope for this patch(set).
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Similar to calling remove_sstable_with_temp_toc later on in
populate_column_family(), we need only one thread to do the
cleanup work and the existing convention is that it's shard 0.
Since lister::rmdir is checking remove_file of all entries
(recursively) and the dir itself, doing that concurrently would fail.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Many area of the code are splattered with unneeded templates. This patchset replaces
some of them, where the template parameter is a function object, with an std::function
or noncopyable_function (with a preference towards the latter; but it is not always
possible). As the template is compiled for each instantiation (if the function
object is a lambda) while a function is compiled only once, there are significant
savings in compile time and bloat.
text data bss dec hex filename
85160690 42120 284910 85487720 5187068 scylla.before
84824762 42120 284910 85151792 5135030 scylla.after
* https://github.com/avikivity/scylla detemplate/v2:
api/commitlog: de-template acquire_cl_metric()
database: de-template do_parse_schema_tables
database: merge for_all_partitions and for_all_partitions_slow
hints: de-template scan_for_hints_dirs()
schema_tables: partially de-template make_map_mutation()
distributed_loader: de-template
tests: commitlog_test: de-template
tests: cql_auth_query_test: de-template
test: de-template eventually() and eventually_true()
tests: flush_queue_test: de-template
hint_test: de-template
tests: mutation_fragment_test: de-template
test: mutation_test: de-template
distributed_loader has several large templates that can be converted to normal
function with the help of noncopyable_function<>, reducing code bloat.
One of the lambdas used as an actual argument was adjusted, because the de-templated
callee only accepts functions returning a future, while the original accepted both
functions returning a future and functions returning void (similar to future::then).
When introducing view update generation path for sstables
in /upload directory, mutating these sstables was moved
to regular path only. It was wrong, because sstables that
need view updates generated from them may still need
to be downgraded to LCS level 0, so they won't disrupt
LCS assumptions after being loaded.
Reported-by: Nadav Har'El <nyh@scylladb.com>
SSTables loaded to the system via /upload dir may sometimes be needed
to generate view updates from them (if their table has accompanying
views).
Fixes#4047
Previous implementation assumes that each SSTable resides directly
in table::datadir directory, while what should actually be used
is directory path from SSTable descriptor.
This patch prevents a regression when adding staging sstables support
for upload/ dir.
