This PR fixes the Installation page:
- Replaces `http `with `https `in the download command.
- Replaces the Open Source example from the Installation section for CentOS (we overlooked this example before).
Fixes https://github.com/scylladb/scylladb/issues/29087
Fixes https://github.com/scylladb/scylladb/issues/29087
This update affects all supported versions and should be backported as a bug fix.
Closesscylladb/scylladb#29088
* github.com:scylladb/scylladb:
doc: remove the Open Source Example from Installation
doc: replace http with https in the installation instructions
The Web Installer page includes instructions to install the old pre-2025.1 Enterprise versions,
which are no longer supported (since we released 2026.1).
This commit removes those redundant and misleading instructions.
Fixes https://github.com/scylladb/scylladb/issues/29099Closesscylladb/scylladb#29103
This commit replaces the Open Soruce example from the Installation section for CentOS.
We updated the example for Ubuntu, but not for CentOS.
We don't want to have any Open Source information in the docs.
Fixes https://github.com/scylladb/scylladb/issues/29087
This commit updates the documentation for the unified installer.
- The Open Source example is replaced with version 2025.1 (Source Available, currently supported, LTS).
- The info about CentOS 7 is removed (no longer supported).
- Java 8 is removed.
- The example for cassandra-stress is removed (as it was already removed on other installation pages).
Fixes https://github.com/scylladb/scylladb/issues/28150Closesscylladb/scylladb#28152
This PR:
- Replaces a fixed version name with the variable for the current version in the instructions for installing a non-default version with Web Installer. This will make using the installer more user-friendly.
- Removes the instruction for Open Source from the Web Installer docs.
Fixes https://github.com/scylladb/scylladb/issues/28005
Fixes https://github.com/scylladb/scylladb/issues/28079Closesscylladb/scylladb#28046
* github.com:scylladb/scylladb:
doc: remove the instruction for Open Source from the Web Installer docs
doc: add the version variable to the Web Installer instructions
This commit replaces a fixed version name with the variable for the current version
in the instructions for installing a non-default version with Web Installer.
This will make using the installer more user-friendly.
Fixes https://github.com/scylladb/scylladb/issues/28005
This commit removes the now redundant driver pages from
the Scylla DB documentation. Instead, the link to the pages
where we moved the diver information is added.
Also, the links are updated across the ScyllaDB manual.
Redirections are added for all the removed pages.
Fixes https://github.com/scylladb/scylladb/issues/26871Closesscylladb/scylladb#27277
Example of installation is out of date, since scylla-5.2 is EOL for long time
upding the example for more recent release (together with packages update)
This PR:
- Removes n1-highmem instances from Recommended Instances.
- Adds missing support for n2-highmem-96.
- Updates the reference to n2 instances in the Google Cloud docs (fixes a broken link to GCP).
- Adds the missing information about processors for n2-highmem-instance - Ice Lake and Cascade Lake (requested by CX).
Fixes https://github.com/scylladb/scylladb/issues/25946
Fixes https://github.com/scylladb/scylladb/issues/24223
Fixes https://github.com/scylladb/scylladb/issues/23976
No backport needed if this PR is merged before 2025.4 branching.
Closesscylladb/scylladb#26182
* github.com:scylladb/scylladb:
doc: update information for n2-highmem instances
doc: remove n1-highmem instances from Recommended Instances
This commit updates the section for n2-highmem instances
on the Cloud Instance Recommendations page
- Added missing support for n2-highmem-96
- Update the reference to n2 instances in the Google Cloud docs.
- Added the missing information about processors for this instance
type (Ice Lake and Cascade Lake).
This commit adds the OS support information for version 2025.1.
In addition, the OS support page is reorganized so that:
- The content is moved from the include page _common/os-support-info.rst
to the regular os-support.rst page. The include page was necessary
to document different support for OSS and Enterprise versions, so
we don't need it anymore.
- I skipped the entries for versions that won't be supported when 2025.1
is released: 6.1 and 2023.1.
- I moved the definition of "supported" to the end of the page for better
readability.
- I've renamed the index entry to "OS Support" to be shorter on the left menu.
Fixes https://github.com/scylladb/scylladb/issues/22474Closesscylladb/scylladb#22476
ICS is a compaction strategy that inherits size tiered properties --
therefore it's write optimized too -- but fixes its space overhead of
100% due to input files being only released on completion. That's
achieved with the concept of sstable run (similar in concept to LCS
levels) which breaks a large sstable into fixed-size chunks (1G by
default), known as run fragments. ICS picks similar-sized runs
for compaction, and fragments of those runs can be released
incrementally as they're compacted, reducing the space overhead
to about (number_of_input_runs * 1G). This allows user to increase
storage density of nodes (from 50% to ~80%), reducing the cost of
ownership.
NOTE: test_system_schema_version_is_stable adjusted to account for batchlog
using IncrementalCompactionStrategy
contains:
compaction/: added incremental_compaction_strategy.cc (.hh), incremental_backlog_tracker.cc (.hh)
compaction/CMakeLists.txt: include ICS cc files
configure.py: changes for ICS files, includes test
db/legacy_schema_migrator.cc / db/schema_tables.cc: fallback to ICS when strategy is not supported
db/system_keyspace: pick ICS for some system tables
schema/schema.hh: ICS becomes default
test/boost: Add incremental_compaction_test.cc
test/boost/sstable_compaction_test.cc: ICS related changes
test/cqlpy/test_compaction_strategy_validation.py: ICS related changes
docs/architecture/compaction/compaction-strategies.rst: changes to ICS section
docs/cql/compaction.rst: changes to ICS section
docs/cql/ddl.rst: adds reference to ICS options
docs/getting-started/system-requirements.rst: updates sentence mentioning ICS
docs/kb/compaction.rst: changes to ICS section
docs/kb/garbage-collection-ics.rst: add file
docs/kb/index.rst: add reference to <garbage-collection-ics>
docs/operating-scylla/procedures/tips/production-readiness.rst: add ICS section
some relevant commits throughout the ICS history:
commit 434b97699b39c570d0d849d372bf64f418e5c692
Merge: 105586f747 30250749b8
Author: Paweł Dziepak <pdziepak@scylladb.com>
Date: Tue Mar 12 12:14:23 2019 +0000
Merge "Introduce Incremental Compaction Strategy (ICS)" from Raphael
"
Introduce new compaction strategy which is essentially like size tiered
but will work with the existing incremental compaction. Thus incremental
compaction strategy.
It works like size tiered, but each element composing a tier is a sstable
run, meaning that the compaction strategy will look for N similar-sized
sstable runs to compact, not just individual sstables.
Parameters:
* "sstable_size_in_mb": defines the maximum sstable (fragment) size
composing
a sstable run, which impacts directly the disk space requirement which is
improved with incremental compaction.
The lower the value the lower the space requirement for compaction because
fragments involved will be released more frequently.
* all others available in size tiered compaction strategy
HOWTO
=====
To change an existing table to use it, do:
ALTER TABLE mykeyspace.mytable WITH compaction =
{'class' : 'IncrementalCompactionStrategy'};
Set fragment size:
ALTER TABLE mykeyspace.mytable WITH compaction =
{'class' : 'IncrementalCompactionStrategy', 'sstable_size_in_mb' : 1000 }
"
commit 94ef3cd29a196bedbbeb8707e20fe78a197f30a1
Merge: dca89ce7a5 e08ef3e1a3
Author: Avi Kivity <avi@scylladb.com>
Date: Tue Sep 8 11:31:52 2020 +0300
Merge "Add feature to limit space amplification in Incremental Compaction" from Raphael
"
A new option, space_amplification_goal (SAG), is being added to ICS. This option
will allow ICS user to set a goal on the space amplification (SA). It's not
supposed to be an upper bound on the space amplification, but rather, a goal.
This new option will be disabled by default as it doesn't benefit write-only
(no overwrites) workloads and could hurt severely the write performance.
The strategy is free to delay triggering this new behavior, in order to
increase overall compaction efficiency.
The graph below shows how this feature works in practice for different values
of space_amplification_goal:
https://user-images.githubusercontent.com/1409139/89347544-60b7b980-d681-11ea-87ab-e2fdc3ecb9f0.png
When strategy finds space amplification crossed space_amplification_goal, it
will work on reducing the SA by doing a cross-tier compaction on the two
largest tiers. This feature works only on the two largest tiers, because taking
into account others, could hurt the compaction efficiency which is based on
the fact that the more similar-sized sstables are compacted together the higher
the compaction efficiency will be.
With SAG enabled, min_threshold only plays an important role on the smallest
tiers, given that the second-largest tier could be compacted into the largest
tier for a space_amplification_goal value < 2.
By making the options space_amplification_goal and min_threshold independent,
user will be able to tune write amplification and space amplification, based on
the needs. The lower the space_amplification_goal the higher the write
amplification, but by increasing the min threshold, the write amplification
can be decreased to a desired amount.
"
commit 7d90911c5fb3fa891ad64a62147c3a6ca26d61b1
Author: Raphael S. Carvalho <raphaelsc@scylladb.com>
Date: Sat Oct 16 13:41:46 2021 -0300
compaction: ICS: Add garbage collection
Today, ICS lacks an approach to persist expired tombstones in a timely manner,
which is a problem because accumulation of tombstones are known to affecting
latency considerably.
For an expired tombstone to be purged, it has to reach the top of the LSM tree
and hope that older overlapping data wasn't introduced at the bottom.
The condition are there and must be satisfied to avoid data resurrection.
STCS, today, has an inefficient garbage collection approach because it only
picks a single sstable, which satisfies the tombstone density threshold and
file staleness. That's a problem because overlapping data either on same tier
or smaller tiers will prevent tombstones from being purged. Also, nothing is
done to push the tombstones to the top of the tree, for the conditions to be
eventually satisfied.
Due to incremental compaction, ICS can more easily have an effecient GC by
doing cross-tier compaction of relevant tiers.
The trigger will be file staleness and tombstone density, which threshold
values can be configured by tombstone_compaction_interval and
tombstone_threshold, respectively.
If ICS finds a tier which meets both conditions, then that tier and the
larger[1] *and* closest-in-size[2] tier will be compacted together.
[1]: A larger tier is picked because we want tombstones to eventually reach the
top of the tree.
[2]: It also has to be the closest-in-size tier as the smaller the size
difference the higher the efficiency of the compaction. We want to minimize
write amplification as much as possible.
The staleness condition is there to prevent the same file from being picked
over and over again in a short interval.
With this approach, ICS will be continuously working to purge garbage while
not hurting overall efficiency on a steady state, as same-tier compactions are
prioritized.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Message-Id: <20211016164146.38010-1-raphaelsc@scylladb.com>
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Closesscylladb/scylladb#22063
This commit removes the raw:: html directive (with the exception of an embedded animation) because:
- It is not supported by the dark theme and looks bad.
- It's a legacy directive, and we no longer need it on index pages.
Fixes https://github.com/scylladb/scylladb/issues/20881Closesscylladb/scylladb#21062
Since JMX server is deprecated, drop them from submodule, build system
and package definition.
Related scylladb/scylla-tools-java#370
Related #14856
Signed-off-by: Takuya ASADA <syuu@scylladb.com>
Closesscylladb/scylladb#17969
