Parallel mysql myisam repair

Posted on 2018-11-21 11:12:25
by Geert Vandeweyer

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Parallel mysql myisam repair

Posted on 2018-11-21 11:12:25
by Geert Vandeweyer

Small script to run the check & repair commands on database server in parallel, to speed up recovery and restart. 

#!/usr/bin/perl

use Parallel::ForkManager;

#nr of threads to use
our $mysqlthreads = 20;

our $pm = Parallel::ForkManager->new($mysqlthreads);

# tables to check and repair
my @tables = `ls /var/lib/mysql/*/*.MYI`;
chomp(@tables);

foreach my $table (@tables)  {
        # force : automatically repair
        # update-state : list when the table was checked and if it was crashed
        # buffer sizes : speed stuff up using bigger bulks of data
        my $cmd = "myisamchk --force --update-state --key_buffer_size=12G --sort_buffer_size=12G --read_buffer_size=1G --write_buffer_size=1G $table";
        $pm->start($table) and next;
        system($cmd) ;
        $pm->finish(0);
}

mysql, Perl, Recovery