flat_mutation_reader make_scrubbing_reader no longer exists
and there is no need to include flat_mutation_reader.hh
nor forward declare the class.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
To be used in the next patch to generate
a string dscription from the compaction_type.
In theory, we could use compaction_name()
btu the latter returns the compaction type
in all-upper case and that is very different from
what we print to the log today. The all-upper
strings are used for the api layer, e.g. to
stop tasks of a particular compaction type.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Use exponential_backoff_retry::retry(abort_source&)
when sleeping between retries and request abort
when the task is stopped.
Fixes#10112
Test: unit(dev)
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
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
Currently compaction_manager tracks sstables
based on !requires_view_building() and similarly,
table::in_strategy_sstables picks up only sstables
that are not in staging.
is_eligible_for_compaction() generalizes this condition
in preparation for adding a quarantine subdirectory for
invalid sstables that should not be compacted as well.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Make compaction procedure switch to table_state. Only function in
compaction.cc still directly using table is
get_fully_expired_sstables(T,...), but subsequently we'll make it
switch to table_state and then we can finally stop including database.hh
in the compaction code.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
info is no longer descriptive, as compaction now works with
compaction_data instead of compaction_info.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Compaction efficiency can be defined as how much backlog is reduced per
byte read or written.
We know a few facts about efficiency:
1) the more files are compacted together (the fan-in) the higher the
efficiency will be, however...
2) the bigger the size difference of input files the worse the
efficiency, i.e. higher write amplification.
so compactions with similar-sized files are the most efficient ones,
and its efficiency increases with a higher number of files.
However, in order to not have bad read amplification, number of files
cannot grow out of bounds. So we have to allow parallel compaction
on different tiers, but to avoid "dilution" of overall efficiency,
we will only allow a compaction to proceed if its efficiency is
greater than or equal to the efficiency of ongoing compactions.
By the time being, we'll assume that strategies don't pick candidates
with wildly different sizes, so efficiency is only calculated as a
function of compaction fan-in.
Now when system is under heavy load, then fan-in threshold will
automatically grow to guarantee that overall efficiency remains
stable.
Please note that fan-in is defined in number of runs. LCS compaction
on higher levels will have a fan-in of 2. Under heavy load, it
may happen that LCS will temporarily switch to size-tiered mode
for compaction to keep up with amount of data being produced.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Message-Id: <20211103215110.135633-2-raphaelsc@scylladb.com>
compaction_info must only contain info data to be exported to the
outside world, whereas compaction_data will contain data for
controlling compaction behavior and stats which change as
compaction progresses.
This separation makes the interface clearer, also allowing for
future improvements like removing direct references to table
in compaction.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
those stats aren't used in compaction stats API and therefore they
can be removed. end_size is added to compaction_result (needed for
updating history) and start_size can be calculated in advance.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Today, compaction is calling compaction manager to register / deregister
the compaction_info created by it.
This is a layer violation because manager sits one layer above
compaction, so manager should be responsible for managing compaction
info.
From now on, compaction_info will be created and managed by
compaction_manager. compaction will only have a reference to info,
which it can use to update the world about compaction progress.
This will allow compaction_manager to be simplified as info can be
coupled with its respective task, allowing duplication to be removed
and layer violation to be fixed.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
this run id is used to track partial runs that are being written to.
let's move it from info into task, as this is not an external info,
but rather one that belongs to compaction_manager.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
The generic backlog formula is: ALL + PARTIAL - COMPACTING
With transfer_ongoing_charges() we already ignore the effect of
ongoing compactions on COMPACTING as we judge them to be pointless.
But ongoing compactions will run to completion, meaning that output
sstables will be added to ALL anyway, in the formula above.
With stop_tracking_ongoing_compactions(), input sstables are never
removed from the tracker, but output sstables are added, which means
we end up with duplicate backlog in the tracker.
By removing this tracking mechanism, pointless ongoing compaction
will be ignored as expected and the leaks will be fixed.
Later, the intention is to force a stop on ongoing compactions if
strategy has changed as they're pointless anyway.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
compaction_info must only contain info data to be exported to the
outside world, whereas compaction_data will contain data for
controlling compaction behavior and stats which change as
compaction progresses.
This separation makes the interface clearer, also allowing for
future improvements like removing direct references to table
in compaction.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
those stats aren't used in compaction stats API and therefore they
can be removed. end_size is added to compaction_result (needed for
updating history) and start_size can be calculated in advance.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Today, compaction is calling compaction manager to register / deregister
the compaction_info created by it.
This is a layer violation because manager sits one layer above
compaction, so manager should be responsible for managing compaction
info.
From now on, compaction_info will be created and managed by
compaction_manager. compaction will only have a reference to info,
which it can use to update the world about compaction progress.
This will allow compaction_manager to be simplified as info can be
coupled with its respective task, allowing duplication to be removed
and layer violation to be fixed.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
this run id is used to track partial runs that are being written to.
let's move it from info into task, as this is not an external info,
but rather one that belongs to compaction_manager.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
The generic back formula is: ALL + PARTIAL - COMPACTING
With transfer_ongoing_charges() we already ignore the effect of
ongoing compactions on COMPACTING as we judge them to be pointless.
But ongoing compactions will run to completion, meaning that output
sstables will be added to ALL anyway, in the formula above.
With stop_tracking_ongoing_compactions(), input sstables are never
removed from the tracker, but output sstables are added, which means
we end up with duplicate backlog in the tracker.
By removing this tracking mechanism, pointless ongoing compaction
will be ignored as expected and the leaks will be fixed.
Later, the intention is to force a stop on ongoing compactions if
strategy has changed as they're pointless anyway.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
the name compaction_options is confusing as it overlaps in meaning
with compaction_descriptor. hard to reason what are the exact
difference between them, without digging into the implementation.
compaction_options is intended to only carry options specific to
a give compaction type, like a mode for scrub, so let's rename
it to compaction_type_options to make it clearer for the
readers.
[avi: adjust for scrub changes]
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Message-Id: <20210908003934.152054-1-raphaelsc@scylladb.com>
Fold validation compaction into scrub compaction (validate mode). Only
on the interface level though: to initiate validation compaction one now
has to use `compaction_options::make_scrub(compaction_options::scrub::mode::validate)`.
The implementation code stays as-is -- separate.
Validation just reads all the passed-in sstables and runs the mutation
stream through a mutation fragment stream validator, logging all errors
found, and finally also logging whether all the sstables are valid or
not. Validation is not really a compaction as it doesn't write any
output. As such it bypasses most of the usual compaction machinery, so
the latter doesn't have to be adapted to this outlier.
This patch only adds the implementation, but it still cannot be started
via `compact_sstables()`, that will be implemented by the next patches.
Since compaction is layered on top of sstables, let's move all compaction code
into a new top-level directory.
This change will give me extra motivation to remove all layer violations, like
sstable calling compaction-specific code, and compaction entanglement with
other components like table and storage service.
Next steps:
- remove all layer violations
- move compaction code in sstables namespace into a new one for compaction.
- move compaction unit tests into its own file
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Message-Id: <20210707194058.87060-1-raphaelsc@scylladb.com>
