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HealthCheck-Parallel-v0.1.0
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/ HealthCheck::Parallel

NAME

HealthCheck::Parallel - A HealthCheck that uses parallelization for running checks

VERSION

version v0.1.0

SYNOPSIS

use HealthCheck::Parallel;

my $hc = HealthCheck::Parallel->new(
    max_procs  => 4,      # default
    timeout    => 120,    # default, global timeout in seconds
    tempdir    => '/tmp', # override Parallel::ForkManager default
    child_init => sub { warn "Will run at start of child process check" },
    checks     => [
        sub { sleep 5; return { id => 'slow1', status => 'OK' } },
        sub { sleep 5; return { id => 'slow2', status => 'OK' } },
    ],
);

# Takes 5 seconds to run both checks instead of 10.
my $res = $hc->check;

# These checks will not use parallelization.
$res = $hc->check( max_procs => 0 );

# Neither will these.
$res = $hc->check( max_procs => 1 );

# Override timeout for specific check.
$res = $hc->check( timeout => 60 );

DESCRIPTION

This library inherits HealthCheck so that the provided checks are run in parallel.

METHODS

new

Overrides the "new" in HealthCheck constructor to additionally allow "max_procs" and "timeout" arguments for controlling parallelization and global timeout behavior.

ATTRIBUTES

max_procs

A positive integer (or coderef returning one) specifying the maximum number of processes that should be run in parallel when executing the checks. No parallelization will be used unless given a value that is greater than 1. Defaults to 4.

If provided as a coderef, it will be called at runtime to determine the value, allowing dynamic adjustment:

my $hc = HealthCheck::Parallel->new(
    max_procs => sub { int(rand(10)) },
    checks    => [ ... ],
);

child_init

An optional coderef which will be run when the child process of a check is created. A possible important use case is making sure child processes don't try to make use of STDOUT if these checks are running under FastCGI envrionment:

my $hc = HealthCheck::Parallel->new(
    child_init => sub {
        untie *STDOUT;
        { no warnings; *FCGI::DESTROY = sub {}; }
    },
);

tempdir

Sets the tempdir value to use in Parallel::ForkManager for IPC.

timeout

A positive integer (or coderef returning one) specifying the maximum number of seconds to wait for all parallelized checks to complete. If the timeout is exceeded, all running child processes will be terminated and CRITICAL results will be returned for affected checks. Defaults to 120 seconds.

If provided as a coderef, it will be called at runtime to determine the value, allowing dynamic adjustment:

my $hc = HealthCheck::Parallel->new(
    timeout => sub { int(rand(10)) },
    checks  => [ ... ],
);

Note: The timeout only applies when parallelization is enabled (max_procs > 1). When max_procs is 0 or 1, checks run in the parent process and the timeout is not used.

The timeout is implemented using a non-blocking polling loop instead of using any signal-based timeouts to potentially avoiding conflicting with others.

DEPENDENCIES

SEE ALSO

AUTHOR

Grant Street Group <developers@grantstreet.com>

COPYRIGHT AND LICENSE

This software is Copyright (c) 2023 - 2025 by Grant Street Group.

This is free software, licensed under:

The Artistic License 2.0 (GPL Compatible)