bencher - A benchmark framework (CLI)
This document describes version 1.056 of bencher (from Perl distribution Bencher), released on 2021-08-13.
List all scenario modules (Bencher::Scenario::*) installed locally on your system:
% bencher --list-scenario-modules % bencher -L
Run benchmark described by a scenario module:
% bencher -m Example
Run benchmark described by a scenario file:
% bencher -f scenario.pl
Add participants from the command-line instead of (or in addition to) those specified in a scenario file/module:
% bencher -p '{"fcall_template":"Bar::func(<arg>)"}'
Run module startup overhead benchmark instead of the normal benchmark:
% bencher -m Example --module-startup
Show/dump scenario instead of running benchmark:
% bencher -m Example --show-scenario
List participants instead of running benchmark:
% bencher ... --list-participants % bencher ... --list-participants -l ;# show detail
List participating Perl modules (modules mentioned by all the participants):
% bencher ... --list-participant-modules % bencher ... --list-participant-modules -l ;# show detail
List datasets instead of running benchmark:
% bencher ... --list-datasets % bencher ... --list-datasets -l ;# show detail
List items instead of running benchmark:
% bencher ... --list-items % bencher ... --list-items -l ;# show detail
Show items' codes instead of running benchmark:
% bencher ... --show-items-codes
Show items' results instead of running benchmark:
% bencher ... --show-items-results
Select (include/exclude) participants before running benchmark (you can also select datasets/modules/items):
% bencher ... --include-participant-pattern 'Tiny|Lite' --exclude-participant 'HTTP::Tiny'
You need to install App::perlbrew first and then install some perls. Also, install at least Bencher::Backend to each perl you want to run the benchmark on.
To list available perls (same as perlbrew list, but also shows whether a perl has Bencher):
perlbrew list
% bencher --list-perls % bencher --list-perls -l
To run a scenario against all perls which have Bencher:
% bencher -m ScenarioModule --multiperl ...
To run a scenario against some perls:
% bencher -m ScenarioModule --multiperl --include-perl perl-5.20.3 --include-perl perl-5.22.1 ...
For example, if version 0.02 of a module is installed and you want to benchmark against version 0.01 (in /my/home/lib):
/my/home/lib
% bencher -m ScenarioModule --multimodver Module::Name -I /my/home/lib ...
Note that Module::Name must be among the modules that are being benchmarked (according to the scenario).
Module::Name
Bencher is a benchmark framework. You specify a scenario (either in a Bencher::Scenario::* Perl module, or a Perl script, or over the command-line) containing list of participants and datasets. Participants are codes or commands to run, and datasets are arguments for the codes/commands. Bencher will permute the participants and datasets into benchmark items, ready to run.
Bencher::Scenario::*
You can choose to include only some participants, datasets, or items. And there are options to view your scenario's participants/datasets/items/mentioned modules, run benchmark against multiple perls and module versions, and so on. Bencher comes as a CLI script as well as Perl module. See the Bencher::Backend documentation for more information.
* marks required options.
*
Show detailed information for each result.
Add an environment hash.
See --env-hashes.
--env-hashes
Add environment hashes (JSON-encoded).
Add environment hashes.
What to do when there is a failure.
Valid values:
["die","skip"]
For a command participant, failure means non-zero exit code. For a Perl-code participant, failure means Perl code dies or (if expected result is specified) the result is not equal to the expected result.
The default is "die". When set to "skip", will first run the code of each item before benchmarking and trap command failure/Perl exception and if that happens, will "skip" the item.
What to do when there is a result failure.
["die","skip","warn"]
This is like `on_failure` except that it specifically refer to the failure of item's result not being equal to expected result.
There is an extra choice of `warn` for this type of failure, which is to print a warning to STDERR and continue.
Set precision limit.
Instead of setting `precision` which forces a single value, you can also set this `precision_limit` setting. If the precision in the scenario is higher (=number is smaller) than this limit, then this limit is used. For example, if the scenario specifies `default_precision` 0.001 and `precision_limit` is set to 0.005 then 0.005 is used.
This setting is useful on slower computers which might not be able to reach the required precision before hitting maximum number of iterations.
Precision.
When benchmarking with the default <pm:Benchmark::Dumb> runner, will pass the precision to it. The value is a fraction, e.g. 0.5 (for 5% precision), 0.01 (for 1% precision), and so on. Or, it can also be a positive integer to speciify minimum number of iterations, usually need to be at least 6 to avoid the "Number of initial runs is very small (<6)" warning. The default precision is 0, which is to let Benchmark::Dumb determine the precision, which is good enough for most cases.
When benchmarking with <pm:Benchmark> runner, will pass this value as the $count argument. Which can be a positive integer to mean the number of iterations to do (e.g. 10, or 100). Or, can also be set to a negative number (e.g. -0.5 or -2) to mean minimum number of CPU seconds. The default is -0.5.
$count
When benchmarking with <pm:Benchmark::Dumb::SimpleTime>, this value is a positive integer which means the number of iterations to perform.
When profiling, a number greater than 1 will set a repetition loop (e.g. for(1..100){ ... }).
for(1..100){ ... }
This setting overrides `default_precision` property in the scenario.
Runner module to use.
["Benchmark::Dumb","Benchmark","Benchmark::Dumb::SimpleTime"]
The default is `Benchmark::Dumb` which should be good enough for most cases.
You can use `Benchmark` runner (`Benchmark.pm`) if you are accustomed to it and want to see its output format.
You can use `Benchmark::Dumb::SimpleTime` if your participant code runs for at least a few to many seconds and you want to use very few iterations (like 1 or 2) because you don't want to wait for too long.
Whether to save benchmark result to file.
Will also be turned on automatically if `BENCHER_RESULT_DIR` environment variabl is defined.
When this is turned on, will save a JSON file after benchmark, containing the result along with metadata. The directory of the JSON file will be determined from the `results_dir` option, while the filename from the `results_filename` option.
Whether to test participant code once first before benchmarking.
By default, participant code is run once first for testing (e.g. whether it dies or return the correct result) before benchmarking. If your code runs for many seconds, you might want to skip this test and set this to 0.
Also return memory usage of item's arguments.
Memory size is measured using <pm:Devel::Size>.
Also return process size information for each item.
This is done by dumping each item's code into a temporary file and running the file with a new perl interpreter process and measuring the process size at the end (so it does not need to load Bencher itself or the other items). Currently only works on Linux because process size information is retrieved from `/proc/PID/smaps`. Not all code can work, e.g. if the code tries to access a closure or outside data or extra modules (modules not specified in the participant or loaded by the code itself). Usually does not make sense to use this on external command participants.
Also return memory usage of each item code's result (return value).
Default value:
"bench"
["list-perls","list-scenario-modules","show-scenario","list-participants","list-participant-modules","list-datasets","list-items","show-items-codes","show-items-results","show-items-results-sizes","show-items-outputs","dump-items","dump-parsed-scenario","profile","bench"]
Benchmark code startup overhead instead of normal benchmark.
Shortcut for -a dump-items.
See --action.
--action
Shortcut for -a dump-parsed-scenario.
Shortcut for -a list-datasets.
Shortcut for -a list-items.
Shortcut for -a list-participant-modules.
Shortcut for -a list-participants.
Shortcut for -a list-perls.
Shortcut for -a list-permutes.
Shortcut for -a list-scenario-modules.
Benchmark module startup overhead instead of normal benchmark.
Shortcut for -a profile.
Shortcut for -a show-items-codes.
Shortcut for -a show-items-outputs.
Shortcut for -a show-items-results.
Shortcut for -a show-items-results-sizes.
Shortcut for -a show-scenario.
Set path to configuration file.
Set configuration profile to use.
Do not use any configuration file.
Add a dataset.
See --datasets.
--datasets
Add datasets (JSON-encoded).
Add datasets.
Do not cleanup temporary directory when bencher ends.
Run perltidy over generated scripts.
Do not read environment for default options.
Add dataset (by name) to exclude list.
Can be specified multiple times.
Exclude datasets whose name matches this (JSON-encoded).
See --exclude-dataset-name.
--exclude-dataset-name
Exclude datasets matching this regex pattern.
Add dataset (by sequence number) to exclude list.
Exclude datasets whose sequence number matches this (JSON-encoded).
See --exclude-dataset-seq.
--exclude-dataset-seq
Add a tag to dataset exclude tag list.
You can specify `A & B` to exclude datasets that have _both_ tags A and B.
Exclude datasets whose tag matches this (JSON-encoded).
See --exclude-dataset-tag.
--exclude-dataset-tag
Add dataset (by name/seq) to exclude list.
Exclude datasets whose seq/name matches this (JSON-encoded).
See --exclude-dataset.
--exclude-dataset
Exclude function(s) matching this regex pattern.
Add function to exclude list.
Exclude functions specified in this list (JSON-encoded).
See --exclude-function.
--exclude-function
Add item (by name) to exclude list.
Exclude items whose name matches this (JSON-encoded).
See --exclude-item-name.
--exclude-item-name
Exclude items matching this regex pattern.
Add item (by sequence number) to exclude list.
Exclude items whose sequence number matches this (JSON-encoded).
See --exclude-item-seq.
--exclude-item-seq
Add item (by name/seq) to exclude list.
Exclude items whose seq/name matches this (JSON-encoded).
See --exclude-item.
--exclude-item
Exclude module(s) matching this regex pattern.
Add module to exclude list.
Exclude modules specified in this list (JSON-encoded).
See --exclude-module.
--exclude-module
Add participant (by name) to exclude list.
Exclude participants whose name matches this (JSON-encoded).
See --exclude-participant-name.
--exclude-participant-name
Exclude participants matching this regex pattern.
Add participant (by sequence number) to exclude list.
Exclude participants whose sequence number matches this (JSON-encoded).
See --exclude-participant-seq.
--exclude-participant-seq
Add a tag to participants exclude tag list.
You can specify `A & B` to exclude participants that have _both_ tags A and B.
Exclude participants whose tag matches this (JSON-encoded).
See --exclude-participant-tag.
--exclude-participant-tag
Add participant (by name/seq) to exclude list.
Exclude participants whose seq/name matches this (JSON-encoded).
See --exclude-participant.
--exclude-participant
Add specified perl to exclude list.
Exclude some perls (JSON-encoded).
See --exclude-perl.
--exclude-perl
Exclude PP (pure-Perl) modules.
Exclude XS modules.
Add dataset (by name) to include list.
Only include datasets whose name matches this (JSON-encoded).
See --include-dataset-name.
--include-dataset-name
Only include datasets matching this regex pattern.
Add dataset (by sequence number) to include list.
Only include datasets whose sequence number matches this (JSON-encoded).
See --include-dataset-seq.
--include-dataset-seq
Add a tag to dataset include tag list.
You can specify `A & B` to include datasets that have _both_ tags A and B.
Only include datasets whose tag matches this (JSON-encoded).
See --include-dataset-tag.
--include-dataset-tag
Add dataset (by name/seq) to include list.
Only include datasets whose seq/name matches this (JSON-encoded).
See --include-dataset.
--include-dataset
Only include functions matching this regex pattern.
Add function to include list.
Only include functions specified in this list (JSON-encoded).
See --include-function.
--include-function
Add item (by name) to include list.
Only include items whose name matches this (JSON-encoded).
See --include-item-name.
--include-item-name
Only include items matching this regex pattern.
Add item (by sequence number) to include list.
Only include items whose sequence number matches this (JSON-encoded).
See --include-item-seq.
--include-item-seq
Add item (by name/seq) to include list.
Only include items whose seq/name matches this (JSON-encoded).
See --include-item.
--include-item
Only include modules matching this regex pattern.
Add module to include list.
Only include modules specified in this list (JSON-encoded).
See --include-module.
--include-module
Add participant (by name) to include list.
Only include participants whose name matches this (JSON-encoded).
See --include-participant-name.
--include-participant-name
Only include participants matching this regex pattern.
Add participant (by sequence number) to include list.
Only include participants whose sequence number matches this (JSON-encoded).
See --include-participant-seq.
--include-participant-seq
Add a tag to participants include tag list.
You can specify `A & B` to include participants that have _both_ tags A and B.
Only include participants whose tag matches this (JSON-encoded).
See --include-participant-tag.
--include-participant-tag
Add participant (by name/seq) to include list.
Only include participants whose seq/name matches this (JSON-encoded).
See --include-participant.
--include-participant
Add specified perl to include list.
Only include some perls (JSON-encoded).
See --include-perl.
--include-perl
Shortcut for --log-level=debug.
Set log level.
Shortcut for --log-level=error.
Shortcut for --log-level=trace.
Shortcut for --log-level=info.
Additional module search paths (JSON-encoded).
See --include-path.
--include-path
Add path to module search path.
Used when searching for scenario module, or when in multimodver mode.
Benchmark multiple module versions.
If set to a module name, will search for all (instead of the first occurrence) of the module in `@INC`. Then will generate items for each version.
Currently only one module can be multi version.
Benchmark against multiple perls.
Requires <pm:App::perlbrew> to be installed. Will use installed perls from the perlbrew installation. Each installed perl must have <pm:Bencher::Backend> module installed (in addition to having all modules that you want to benchmark, obviously).
By default, only perls having Bencher::Backend will be included. Use `--include-perl` and `--exclude-perl` to include and exclude which perls you want.
Also note that due to the way this is currently implemented, benchmark code that contains closures (references to variables outside the code) won't work.
Trap output to stderr.
Trap output to stdout.
Choose output format, e.g. json, text.
undef
Set output format to json.
When outputing as JSON, strip result envelope.
0
By default, when outputing as JSON, the full enveloped result is returned, e.g.:
[200,"OK",[1,2,3],{"func.extra"=>4}]
The reason is so you can get the status (1st element), status message (2nd element) as well as result metadata/extra result (4th element) instead of just the result (3rd element). However, sometimes you want just the result, e.g. when you want to pipe the result for more post-processing. In this case you can use `--naked-res` so you just get:
[1,2,3]
Put additional note in the result.
Filter output through a pager.
Show "raw" data.
When action=show-items-result, will print result as-is instead of dumping as Perl.
Format result like Benchmark.pm.
Directory to use when saving benchmark result.
Default is from `BENCHER_RESULT_DIR` environment variable, or the home directory.
Filename to use when saving benchmark result.
Default is:
<NAME>.<yyyy-dd-dd-"T"HH-MM-SS>.json
or, when running in module startup mode:
<NAME>.module_startup.<yyyy-dd-dd-"T"HH-MM-SS>.json
or, when running in code startup mode:
<NAME>.code_startup.<yyyy-dd-dd-"T"HH-MM-SS>.json
where <NAME> is scenario module name, or `NO_MODULE` if scenario is not from a module. The `::` (double colon in the module name will be replaced with `-` (dash).
Whether to return extra metadata.
When set to true, will return extra metadata such as platform information, CPU information, system load before & after the benchmark, system time, and so on. This is put in result metadata under `func.*` keys.
The default is to true (return extra metadata) unless when run as CLI and format is text (where the extra metadata is not shown).
["-time"]
See --sort.
--sort
View output using a viewer.
Load a scenario from an Acme::CPANModules:: Perl module.
An <pm:Acme::CPANModules> module can also contain benchmarking information, e.g. <pm:Acme::CPANModules::TextTable>.
Add a participant.
See --participants.
--participants
Add participants (JSON-encoded).
Add participants.
Load a scenario from a Perl file.
Perl file will be do()'ed and the last expression should be a hash containing the scenario specification.
Load a scenario from data structure (JSON-encoded).
See --scenario.
--scenario
Load a scenario from a Bencher::Scenario:: Perl module.
Will try to load module `Bencher::Scenario::<NAME>` and expect to find a package variable in the module called `$scenario` which should be a hashref containing the scenario specification.
Load a scenario from data structure.
Display help message and exit.
Display program's version and exit.
This script has shell tab completion capability with support for several shells.
To activate bash completion for this script, put:
complete -C bencher bencher
in your bash startup (e.g. ~/.bashrc). Your next shell session will then recognize tab completion for the command. Or, you can also directly execute the line above in your shell to activate immediately.
It is recommended, however, that you install modules using cpanm-shcompgen which can activate shell completion for scripts immediately.
To activate tcsh completion for this script, put:
complete bencher 'p/*/`bencher`/'
in your tcsh startup (e.g. ~/.tcshrc). Your next shell session will then recognize tab completion for the command. Or, you can also directly execute the line above in your shell to activate immediately.
It is also recommended to install shcompgen (see above).
For fish and zsh, install shcompgen as described above.
This script can read configuration files. Configuration files are in the format of IOD, which is basically INI with some extra features.
By default, these names are searched for configuration filenames (can be changed using --config-path): ~/.config/bencher.conf, ~/bencher.conf, or /etc/bencher.conf.
--config-path
All found files will be read and merged.
To disable searching for configuration files, pass --no-config.
--no-config
You can put multiple profiles in a single file by using section names like [profile=SOMENAME] or [SOMESECTION profile=SOMENAME]. Those sections will only be read if you specify the matching --config-profile SOMENAME.
[profile=SOMENAME]
[SOMESECTION profile=SOMENAME]
--config-profile SOMENAME
You can also put configuration for multiple programs inside a single file, and use filter program=NAME in section names, e.g. [program=NAME ...] or [SOMESECTION program=NAME]. The section will then only be used when the reading program matches.
program=NAME
[program=NAME ...]
[SOMESECTION program=NAME]
You can also filter a section by environment variable using the filter env=CONDITION in section names. For example if you only want a section to be read if a certain environment variable is true: [env=SOMEVAR ...] or [SOMESECTION env=SOMEVAR ...]. If you only want a section to be read when the value of an environment variable equals some string: [env=HOSTNAME=blink ...] or [SOMESECTION env=HOSTNAME=blink ...]. If you only want a section to be read when the value of an environment variable does not equal some string: [env=HOSTNAME!=blink ...] or [SOMESECTION env=HOSTNAME!=blink ...]. If you only want a section to be read when the value of an environment variable includes some string: [env=HOSTNAME*=server ...] or [SOMESECTION env=HOSTNAME*=server ...]. If you only want a section to be read when the value of an environment variable does not include some string: [env=HOSTNAME!*=server ...] or [SOMESECTION env=HOSTNAME!*=server ...]. Note that currently due to simplistic parsing, there must not be any whitespace in the value being compared because it marks the beginning of a new section filter or section name.
env=CONDITION
[env=SOMEVAR ...]
[SOMESECTION env=SOMEVAR ...]
[env=HOSTNAME=blink ...]
[SOMESECTION env=HOSTNAME=blink ...]
[env=HOSTNAME!=blink ...]
[SOMESECTION env=HOSTNAME!=blink ...]
[env=HOSTNAME*=server ...]
[SOMESECTION env=HOSTNAME*=server ...]
[env=HOSTNAME!*=server ...]
[SOMESECTION env=HOSTNAME!*=server ...]
To load and configure plugins, you can use either the -plugins parameter (e.g. -plugins=DumpArgs or -plugins=DumpArgs@before_validate_args), or use the [plugin=NAME ...] sections, for example:
-plugins
-plugins=DumpArgs
-plugins=DumpArgs@before_validate_args
[plugin=NAME ...]
[plugin=DumpArgs] -event=before_validate_args -prio=99 [plugin=Foo] -event=after_validate_args arg1=val1 arg2=val2
which is equivalent to setting -plugins=-DumpArgs@before_validate_args@99,-Foo@after_validate_args,arg1,val1,arg2,val2.
-plugins=-DumpArgs@before_validate_args@99,-Foo@after_validate_args,arg1,val1,arg2,val2
List of available configuration parameters:
action (see --action) capture_stderr (see --capture-stderr) capture_stdout (see --capture-stdout) code_startup (see --code-startup) cpanmodules_module (see --cpanmodules-module) datasets (see --datasets) detail (see --detail) env_hashes (see --env-hashes) exclude_dataset_names (see --exclude-dataset-name) exclude_dataset_pattern (see --exclude-dataset-pattern) exclude_dataset_seqs (see --exclude-dataset-seq) exclude_dataset_tags (see --exclude-dataset-tag) exclude_datasets (see --exclude-dataset) exclude_function_pattern (see --exclude-function-pattern) exclude_functions (see --exclude-function) exclude_item_names (see --exclude-item-name) exclude_item_pattern (see --exclude-item-pattern) exclude_item_seqs (see --exclude-item-seq) exclude_items (see --exclude-item) exclude_module_pattern (see --exclude-module-pattern) exclude_modules (see --exclude-module) exclude_participant_names (see --exclude-participant-name) exclude_participant_pattern (see --exclude-participant-pattern) exclude_participant_seqs (see --exclude-participant-seq) exclude_participant_tags (see --exclude-participant-tag) exclude_participants (see --exclude-participant) exclude_perls (see --exclude-perl) exclude_pp_modules (see --exclude-pp-modules) exclude_xs_modules (see --exclude-xs-modules) format (see --format) include_dataset_names (see --include-dataset-name) include_dataset_pattern (see --include-dataset-pattern) include_dataset_seqs (see --include-dataset-seq) include_dataset_tags (see --include-dataset-tag) include_datasets (see --include-dataset) include_function_pattern (see --include-function-pattern) include_functions (see --include-function) include_item_names (see --include-item-name) include_item_pattern (see --include-item-pattern) include_item_seqs (see --include-item-seq) include_items (see --include-item) include_module_pattern (see --include-module-pattern) include_modules (see --include-module) include_participant_names (see --include-participant-name) include_participant_pattern (see --include-participant-pattern) include_participant_seqs (see --include-participant-seq) include_participant_tags (see --include-participant-tag) include_participants (see --include-participant) include_path (see --include-path) include_perls (see --include-perl) keep_tempdir (see --keep-tempdir) log_level (see --log-level) module_startup (see --module-startup) multimodver (see --multimodver) multiperl (see --multiperl) naked_res (see --naked-res) note (see --note) on_failure (see --on-failure) on_result_failure (see --on-result-failure) participants (see --participants) precision (see --precision) precision_limit (see --precision-limit) raw (see --raw) render_as_benchmark_pm (see --render-as-benchmark-pm) result_dir (see --result-dir) result_filename (see --result-filename) return_meta (see --return-meta) runner (see --runner) save_result (see --save-result) scenario (see --scenario) scenario_file (see --scenario-file) scenario_module (see --scenario-module) scientific_notation (see --scientific-notation) sorts (see --sort) test (see --test) tidy (see --tidy) with_args_size (see --with-args-size) with_process_size (see --with-process-size) with_result_size (see --with-result-size)
Specify additional command-line options.
Set default for --results-dir.
--results-dir
~/.config/bencher.conf
~/bencher.conf
/etc/bencher.conf
Please visit the project's homepage at https://metacpan.org/release/Bencher.
Source repository is at https://github.com/perlancar/perl-Bencher.
Please report any bugs or feature requests on the bugtracker website https://rt.cpan.org/Public/Dist/Display.html?Name=Bencher
When submitting a bug or request, please include a test-file or a patch to an existing test-file that illustrates the bug or desired feature.
bencher-tiny if you want a simpler CLI with no non-core dependencies.
Bencher
Bencher::Backend
Bencher::Manual::*
perlancar <perlancar@cpan.org>
To contribute, you can send patches by email/via RT, or send pull requests on GitHub.
Most of the time, you don't need to build the distribution yourself. You can simply modify the code, then test via:
% prove -l
If you want to build the distribution (e.g. to try to install it locally on your system), you can install Dist::Zilla, Dist::Zilla::PluginBundle::Author::PERLANCAR, and sometimes one or two other Dist::Zilla plugin and/or Pod::Weaver::Plugin. Any additional steps required beyond that are considered a bug and can be reported to me.
This software is copyright (c) 2021, 2020, 2019, 2018, 2017, 2016, 2015 by perlancar <perlancar@cpan.org>.
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.
To install Bencher, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Bencher
CPAN shell
perl -MCPAN -e shell install Bencher
For more information on module installation, please visit the detailed CPAN module installation guide.