Files
scylladb/docs
Avi Kivity fe7e63f109 Merge 'transport: service_level_controller: create and use driver service level' from Andrzej Jackowski
This patch series:
 - Increases the number of allowed scheduling groups to allow creation of `sl:driver`
 - Implements `create_driver_service_level` that creates `sl:driver` with shares=200 if it wasn't already created
 - Implements creation of `sl:driver` for new systems and tests in `raft_initialize_discovery_leader`
 - Modifies `topology_coordinator` to use  create `sl:driver` after upgrades.
 - Implements using `sl:driver` for new connections in `transport/server`
 - Adds to `transport/server` recognition of driver's control connections and forcing them to keep using `sl:driver`.
 - Adds tests to verify the new functionality
 - Modifies existing tests to let them pass after `sl:driver` is added
 - Modifies the documentation to contain new `sl:driver`

The changes were evaluated by a test with the following scenario ([test_connections-sl-driver.py](https://github.com/user-attachments/files/22021273/test_connections-sl-driver.py)):
 - Start ScyllaDB with one node
 - Create 1000 keyspaces, 1 table in each keyspace
 - Start `cassandra-stress` (`-rate threads=50  -mode native cql3`)
 - Run connection storm with 1000 session (100 python processes, 10 sessions each)

The maximum latency during connection storm dropped **from 224.94ms to 41.43ms** (those numbers are average from 20 test executions, were max latency was in [140ms, 361ms] before change and [31.4ms, 61.5ms] after).

The snippet of cassandra-stress output from the moment of connection storm:
Before:
```
type       total ops,    op/s,    pk/s,   row/s,    mean,     med,     .95,     .99,    .999,     max,   time,   stderr, errors,  gc: #,  max ms,  sum ms,  sdv ms,      mb
...
total,        789206,   85887,   85887,   85887,     0.6,     0.3,     2.0,     2.0,     2.5,     5.0,    9.0,  0.09679,      0,      0,       0,       0,       0,       0
total,        909322,  120116,  120116,  120116,     0.4,     0.2,     1.9,     2.0,     2.1,     3.1,   10.0,  0.09053,      0,      0,       0,       0,       0,       0
total,        964392,   55070,   55070,   55070,     0.9,     0.4,     2.0,     4.5,     7.7,    18.9,   11.0,  0.09203,      0,      0,       0,       0,       0,       0
total,        975705,   11313,   11313,   11313,     4.4,     3.5,     6.5,    24.5,    82.7,    83.0,   12.0,  0.11713,      0,      0,       0,       0,       0,       0
total,        987548,   11843,   11843,   11843,     4.2,     3.5,     6.5,    33.7,    48.6,    51.5,   13.0,  0.13366,      0,      0,       0,       0,       0,       0
total,        995422,    7874,    7874,    7874,     6.3,     4.0,     7.7,    85.6,   112.9,   113.5,   14.0,  0.14753,      0,      0,       0,       0,       0,       0
total,       1007228,   11806,   11806,   11806,     4.3,     3.5,     6.5,    29.1,    43.8,    87.1,   15.0,  0.15598,      0,      0,       0,       0,       0,       0
total,       1012840,    5612,    5612,    5612,     8.2,     5.0,    11.5,   121.8,   166.6,   170.1,   16.0,  0.16535,      0,      0,       0,       0,       0,       0
total,       1016186,    3346,    3346,    3346,    13.4,     7.4,    20.1,   204.9,   207.6,   210.4,   17.0,  0.17405,      0,      0,       0,       0,       0,       0
total,       1025462,    9276,    9276,    9276,     6.3,     3.9,     9.6,    74.6,   206.8,   210.0,   18.0,  0.17800,      0,      0,       0,       0,       0,       0
total,       1035979,   10517,   10517,   10517,     4.8,     3.5,     6.7,    38.5,    82.6,    83.0,   19.0,  0.18120,      0,      0,       0,       0,       0,       0
total,       1047488,   11509,   11509,   11509,     4.3,     3.5,     6.0,    32.6,    72.3,    74.0,   20.0,  0.18334,      0,      0,       0,       0,       0,       0
total,       1077456,   29968,   29968,   29968,     1.7,     1.6,     2.9,     3.6,     7.0,     8.2,   21.0,  0.17943,      0,      0,       0,       0,       0,       0
total,       1105490,   28034,   28034,   28034,     1.8,     1.8,     3.5,     4.6,     5.3,    13.8,   22.0,  0.17609,      0,      0,       0,       0,       0,       0
total,       1132221,   26731,   26731,   26731,     1.9,     1.8,     3.8,     5.2,     8.4,    11.1,   23.0,  0.17314,      0,      0,       0,       0,       0,       0
total,       1162149,   29928,   29928,   29928,     1.7,     1.7,     3.0,     4.5,     8.0,     9.1,   24.0,  0.16950,      0,      0,       0,       0,       0,       0
...
```

After:
```
type       total ops,    op/s,    pk/s,   row/s,    mean,     med,     .95,     .99,    .999,     max,   time,   stderr, errors,  gc: #,  max ms,  sum ms,  sdv ms,      mb
...
total,        822863,   94379,   94379,   94379,     0.5,     0.3,     2.0,     2.0,     2.1,     3.7,    9.0,  0.06669,      0,      0,       0,       0,       0,       0
total,        937337,  114474,  114474,  114474,     0.4,     0.2,     2.0,     2.0,     2.1,     3.4,   10.0,  0.06301,      0,      0,       0,       0,       0,       0
total,        986630,   49293,   49293,   49293,     1.0,     1.0,     2.0,     2.1,    17.9,    19.0,   11.0,  0.07318,      0,      0,       0,       0,       0,       0
total,       1026734,   40104,   40104,   40104,     1.2,     1.0,     2.0,     2.2,     6.3,     7.1,   12.0,  0.08410,      0,      0,       0,       0,       0,       0
total,       1066124,   39390,   39390,   39390,     1.3,     1.0,     2.0,     2.2,     2.6,     3.4,   13.0,  0.09108,      0,      0,       0,       0,       0,       0
total,       1103082,   36958,   36958,   36958,     1.3,     1.1,     2.1,     2.5,     3.1,     4.2,   14.0,  0.09643,      0,      0,       0,       0,       0,       0
total,       1141987,   38905,   38905,   38905,     1.3,     1.0,     2.0,     2.4,    11.4,    12.7,   15.0,  0.09894,      0,      0,       0,       0,       0,       0
total,       1180023,   38036,   38036,   38036,     1.3,     1.0,     2.0,     3.7,     5.6,     7.1,   16.0,  0.10070,      0,      0,       0,       0,       0,       0
total,       1216481,   36458,   36458,   36458,     1.4,     1.0,     2.1,     3.6,     4.7,     5.0,   17.0,  0.10210,      0,      0,       0,       0,       0,       0
total,       1256819,   40338,   40338,   40338,     1.2,     1.0,     2.0,     2.2,     3.5,     5.4,   18.0,  0.10173,      0,      0,       0,       0,       0,       0
total,       1295122,   38303,   38303,   38303,     1.3,     1.0,     2.0,     2.4,    21.0,    21.1,   19.0,  0.10136,      0,      0,       0,       0,       0,       0
total,       1334743,   39621,   39621,   39621,     1.3,     1.0,     2.0,     2.3,     3.3,     4.0,   20.0,  0.10055,      0,      0,       0,       0,       0,       0
total,       1375579,   40836,   40836,   40836,     1.2,     1.0,     2.0,     2.1,     3.4,     5.7,   21.0,  0.09927,      0,      0,       0,       0,       0,       0
total,       1415576,   39997,   39997,   39997,     1.2,     1.0,     2.0,     2.3,     3.2,     4.1,   22.0,  0.09807,      0,      0,       0,       0,       0,       0
total,       1449268,   33692,   33692,   33692,     1.5,     1.4,     2.5,     3.2,     4.2,     5.6,   23.0,  0.09800,      0,      0,       0,       0,       0,       0
total,       1471873,   22605,   22605,   22605,     2.2,     2.0,     4.8,     5.9,     7.0,     7.9,   24.0,  0.10015,      0,      0,       0,       0,       0,       0
...
```

Fixes: https://github.com/scylladb/scylladb/issues/24411

This is a new feature, so no backport needed.

Closes scylladb/scylladb#25412

* github.com:scylladb/scylladb:
  docs: workload-prioritization: add driver service level
  test: add test to verify use of `sl:driver`
  transport: use `sl:driver` to handle driver's control connections
  transport: whitespace only change in update_scheduling_group
  transport: call update_scheduling_group for non-auth connections
  generic_server: transport: start using `sl:driver` for new connections
  test: add test_desc_* for driver service level
  test: service_levels: add tests for sl:driver creation and removal
  test: add reload_raft_topology_state() to ScyllaRESTAPIClient
  service_level_controller: automatically create `sl:driver`
  service_level_controller: methods to create driver service level
  service_level_controller: handle special sl:driver in DESC output
  topology_coordinator: add service_level_controller reference
  system_keyspace: add service_level_driver_created
  test: add MAX_USER_SERVICE_LEVELS
2025-09-18 19:45:17 +03:00
..
2025-08-11 13:13:37 +02:00
2025-09-17 14:47:13 +02:00
2025-08-12 10:33:06 +03:00
2024-11-06 14:09:28 +02:00
2025-08-22 09:50:07 +03:00
2025-02-20 11:24:34 +02:00
2025-05-13 13:29:04 +03:00

ScyllaDB Documentation

This repository contains the source files for ScyllaDB documentation.

  • The dev folder contains developer-oriented documentation related to the ScyllaDB code base. It is not published and is only available via GitHub.
  • All other folders and files contain user-oriented documentation related to ScyllaDB and are sources for docs.scylladb.com/manual.

To report a documentation bug or suggest an improvement, open an issue in GitHub issues for this project.

To contribute to the documentation, open a GitHub pull request.

Key Guidelines for Contributors

To prevent the build from failing:

  • If you add a new file, ensure it's added to an appropriate toctree, for example:

     .. toctree::
        :maxdepth: 2
        :hidden:
    
        Page X </folder1/article1>
        Page Y </folder1/article2>
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    ----------------------
    Prerequisites
    ----------------------
    

Building User Documentation

Prerequisites

  • Python
  • poetry
  • make

See the ScyllaDB Sphinx Theme prerequisites to check which versions of the above are currently required.

Mac OS X

You must have a working Homebrew in order to install the needed tools.

You also need the standard utility make.

Check if you have these two items with the following commands:

brew help
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Linux Distributions

Building the user docs should work out of the box on most Linux distributions.

Windows

Use "Bash on Ubuntu on Windows" for the same tools and capabilities as on Linux distributions.

Building the Docs

  1. Run make preview to build the documentation.
  2. Preview the built documentation locally at http://127.0.0.1:5500/.

Cleanup

You can clean up all the build products and auto-installed Python stuff with:

make pristine

Information for Contributors

If you are interested in contributing to Scylla docs, please read the Scylla open source page at http://www.scylladb.com/opensource/ and complete a Scylla contributor agreement if needed. We can only accept documentation pull requests if we have a contributor agreement on file for you.

Third-party Documentation

  • Do any copying as a separate commit. Always commit an unmodified version first and then do any editing in a separate commit.

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