Files
scylladb/docs
Botond Dénes 055a36ae55 main: dump diagnostics on SIGQUIT
Dump a diagnostics report on each shard when receiving a SIGQUIT. The
report is logged with a dedicated logger, called diagnostics.
The report has multiple parts:
* seastar memory diagnostics, similar to that printed by the scylla
  memory command (from scylla-gdb.py).
* reader concurrency semaphore diagnostics for each semaphore.

Example report:

    INFO  2024-11-27 01:31:55,882 [shard 0:main] diagnostics - Diagnostics dump requested via SIGQUIT:
    Dumping seastar memory diagnostics
    Used memory:   3988M
    Free memory:   58M
    Total memory:  4G
    Hard failures: 0

    LSA
      allocated: 4M
      used:      16
      free:      4G

    Cache:
      total: 1M
      used:  642K
      free:  398K

    Memtables:
     total: 3M
     Regular:
      real dirty: 0B
      virt dirty: 0B
     System:
      real dirty: 3M
      virt dirty: 3M

    Replica:
      Read Concurrency Semaphores:
        user: 0/100, 0B/81M, queued: 0
        streaming: 0/10, 0B/81M, queued: 0
        system: 0/10, 0B/81M, queued: 0
        compaction: 0/unlimited, 0B/unlimited
        view update: 0/50, 0B/40M, queued: 0
      Execution Stages:
        apply stage:
             Total: 0
      Tables - Ongoing Operations:
        Pending writes (top 10):
          0 Total (all)
        Pending reads (top 10):
          0 Total (all)
        Pending streams (top 10):
          0 Total (all)

    Small pools:
    objsz spansz usedobj memory unused wst%
        8     4K     858    16K     9K   58
       10     4K       5     8K     8K   99
       12     4K       5     8K     8K   99
       14     4K       0     0B     0B    0
       16     4K      2k    44K    15K   35
       32     4K      4k   136K    16K   11
       32     4K      8k   280K    24K    8
       32     4K      3k    92K     6K    6
       32     4K      4k   140K    21K   14
       48     4K      3k   180K    25K   14
       48     4K      2k   120K    27K   22
       64     4K      2k   156K    18K   11
       64     4K     19k     1M    11K    0
       80     4K      3k   236K    16K    6
       96     4K      6k   572K    49K    8
      112     4K      2k   276K    72K   25
      128     4K     477    80K    20K   25
      160     4K     194    60K    30K   49
      192     4K      1k   232K    39K   16
      224     4K      2k   468K    15K    3
      256     4K     182   100K    55K   54
      320     8K     349   152K    43K   28
      384     8K     332   288K   164K   56
      448     4K     243   180K    74K   40
      512     4K     256   244K   116K   47
      640    16K     185   192K    76K   39
      768    16K     394   432K   137K   31
      896     8K      54   192K   144K   75
     1024     4K     288   432K   144K   33
     1280    32K      92   256K   140K   54
     1536    32K      11   128K   111K   86
     1792    16K      10   144K   126K   87
     2048     8K     487     1M    90K    8
     2560    64K     113   384K   100K   26
     3072    64K       9   256K   228K   89
     3584    32K       3   288K   277K   96
     4096    16K     129   912K   396K   43
     5120   128K      21   384K   275K   71
     6144   128K       4   512K   486K   94
     7168    64K       3   576K   553K   96
     8192    32K     373     3M    56K    1
    10240    64K       6   832K   770K   92
    12288    64K      17   960K   756K   78
    14336   128K       2     1M     1M   97
    16384    64K      14     1M   992K   81

    Page spans:
    index  size  free  used spans
        0    4K    4K    5M    1k
        1    8K    8K    2M   213
        2   16K   16K    2M   106
        3   32K   64K    6M   200
        4   64K   64K    4M    71
        5  128K  384K 3934M   31k
        6  256K    1M  256K     5
        7  512K  512K  512K     2
        8    1M    2M    0B     2
        9    2M    2M    2M     2
       10    4M    4M    0B     1
       11    8M   16M    0B     2
       12   16M   32M    0B     2
       13   32M    0B   32M     1
       14   64M    0B    0B     0
       15  128M    0B    0B     0
       16  256M    0B    0B     0
       17  512M    0B    0B     0
       18    1G    0B    0B     0
       19    2G    0B    0B     0
       20    4G    0B    0B     0
       21    8G    0B    0B     0
       22   16G    0B    0B     0
       23   32G    0B    0B     0
       24   64G    0B    0B     0
       25  128G    0B    0B     0
       26  256G    0B    0B     0
       27  512G    0B    0B     0
       28    1T    0B    0B     0
       29    2T    0B    0B     0
       30    4T    0B    0B     0
       31    8T    0B    0B     0

    INFO  2024-11-27 01:31:55,882 [shard 0:main] diagnostics - Diagnostics dump requested via SIGQUIT:
    Semaphore user with 0/100 count and 0/84850769 memory resources: user request, dumping permit diagnostics:

    permits	count	memory	table/operation/state

    0	0	0B	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: 0
    reads_enqueued_for_admission: 0
    reads_enqueued_for_memory: 0
    reads_admitted_immediately: 0
    reads_queued_because_ready_list: 0
    reads_queued_because_need_cpu_permits: 0
    reads_queued_because_memory_resources: 0
    reads_queued_because_count_resources: 0
    reads_queued_with_eviction: 0
    total_permits: 0
    current_permits: 0
    need_cpu_permits: 0
    awaits_permits: 0
    disk_reads: 0
    sstables_read: 0
    INFO  2024-11-27 01:31:55,882 [shard 0:main] diagnostics - Diagnostics dump requested via SIGQUIT:
    Semaphore streaming with 0/10 count and 0/84850769 memory resources: user request, dumping permit diagnostics:

    permits	count	memory	table/operation/state

    0	0	0B	total

    Stats:
    permit_based_evictions: 0
    time_based_evictions: 0
    inactive_reads: 0
    total_successful_reads: 6
    total_failed_reads: 0
    total_reads_shed_due_to_overload: 0
    total_reads_killed_due_to_kill_limit: 0
    reads_admitted: 6
    reads_enqueued_for_admission: 0
    reads_enqueued_for_memory: 0
    reads_admitted_immediately: 6
    reads_queued_because_ready_list: 0
    reads_queued_because_need_cpu_permits: 0
    reads_queued_because_memory_resources: 0
    reads_queued_because_count_resources: 0
    reads_queued_with_eviction: 0
    total_permits: 6
    current_permits: 0
    need_cpu_permits: 0
    awaits_permits: 0
    disk_reads: 0
    sstables_read: 0
    INFO  2024-11-27 01:31:55,882 [shard 0:main] diagnostics - Diagnostics dump requested via SIGQUIT:
    Semaphore compaction with 0/2147483647 count and 0/9223372036854775807 memory resources: user request, dumping permit diagnostics:

    permits	count	memory	table/operation/state

    0	0	0B	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: 0
    reads_enqueued_for_admission: 0
    reads_enqueued_for_memory: 0
    reads_admitted_immediately: 0
    reads_queued_because_ready_list: 0
    reads_queued_because_need_cpu_permits: 0
    reads_queued_because_memory_resources: 0
    reads_queued_because_count_resources: 0
    reads_queued_with_eviction: 0
    total_permits: 27
    current_permits: 0
    need_cpu_permits: 0
    awaits_permits: 0
    disk_reads: 0
    sstables_read: 0
    INFO  2024-11-27 01:31:55,882 [shard 0:main] diagnostics - Diagnostics dump requested via SIGQUIT:
    Semaphore system with 0/10 count and 0/84850769 memory resources: user request, dumping permit diagnostics:

    permits	count	memory	table/operation/state
    1	0	0B	*.*/view_builder/active

    1	0	0B	total

    Stats:
    permit_based_evictions: 0
    time_based_evictions: 0
    inactive_reads: 0
    total_successful_reads: 234
    total_failed_reads: 0
    total_reads_shed_due_to_overload: 0
    total_reads_killed_due_to_kill_limit: 0
    reads_admitted: 234
    reads_enqueued_for_admission: 154
    reads_enqueued_for_memory: 0
    reads_admitted_immediately: 80
    reads_queued_because_ready_list: 154
    reads_queued_because_need_cpu_permits: 0
    reads_queued_because_memory_resources: 0
    reads_queued_because_count_resources: 0
    reads_queued_with_eviction: 0
    total_permits: 235
    current_permits: 1
    need_cpu_permits: 0
    awaits_permits: 0
    disk_reads: 0
    sstables_read: 0
    INFO  2024-11-27 01:31:55,882 [shard 0:main] diagnostics - Diagnostics dump requested via SIGQUIT:
    Semaphore view_update with 0/50 count and 0/42425384 memory resources: user request, dumping permit diagnostics:

    permits	count	memory	table/operation/state

    0	0	0B	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: 0
    reads_enqueued_for_admission: 0
    reads_enqueued_for_memory: 0
    reads_admitted_immediately: 0
    reads_queued_because_ready_list: 0
    reads_queued_because_need_cpu_permits: 0
    reads_queued_because_memory_resources: 0
    reads_queued_because_count_resources: 0
    reads_queued_with_eviction: 0
    total_permits: 0
    current_permits: 0
    need_cpu_permits: 0
    awaits_permits: 0
    disk_reads: 0
    sstables_read: 0

Fixes: scylladb/scylladb#7400

Closes scylladb/scylladb#21692
2024-11-28 18:52:29 +02:00
..
2024-08-20 12:21:39 +03:00
2024-10-22 09:22:32 +03:00
2024-11-06 14:09:28 +02:00
2024-10-27 19:57:59 +02:00
2024-10-07 13:55:15 +03:00
2024-11-06 14:09:28 +02:00
2024-10-07 13:55:15 +03:00
2024-11-06 14:09:28 +02:00
2024-09-27 14:35:39 +02:00

ScyllaDB Documentation

This repository contains the source files for ScyllaDB Open Source 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 Open Source and are sources for opensource.docs.scylladb.com.

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>
        Your New Page </folder1/your-new-article>
    
  • Make sure the link syntax is correct. See the guidelines on creating links

  • Make sure the section headings are correct. See the guidelines on creating headings Note that the markup must be at least as long as the text in the heading. For example:

    ----------------------
    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
make -h

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.

  • We already have a copy of the Apache license in our tree, so you do not need to commit a copy of the license.

  • Include the copyright header from the source file in the edited version. If you are copying an Apache Cassandra document with no copyright header, use:

This document includes material from Apache Cassandra.
Apache Cassandra is Copyright 2009-2014 The Apache Software Foundation.