Re: [Moosefs-users] changelogs on the metalogger

[Bán M. <ba...@vo...>]

On Tue, 7 Sep 2010 11:44:46 +0200
Michał Borychowski <mic...@ge...> wrote:

> Please, send these two scripts to the list so that we can have a look
> at them
> 
> 
I start these scripts from the init.d 

on the masterserver:

#!/usr/bin/perl

use strict;
use IO::Socket;
use Net::hostent;

my $mfsserver = '/usr/sbin/mfsmaster';
my $port = 7990;
my $data_path = "/var/lib/mfs";
my ($server, $client, $hostinfo, $n, $foo, $buf);

$server = IO::Socket::INET->new( Proto     => 'tcp',
                                 LocalPort => $port,
                                 Listen    => SOMAXCONN,
                                 Reuse     => 1);

die "can't setup server" unless $server;
print "[Server $0 accepting clients]\n";

system("$mfsserver start");
print "[mfsmaster server has been started]\n";

while ($client = $server->accept()) {
   $client->autoflush(1);
   $hostinfo = gethostbyaddr($client->peeraddr);
   while ( <$client>) {
     next unless /\S/;
     if    (/^close$/i)    { last; }
     elsif (/^(meta:)/) { 
         $n = $';
         chomp($n);
         $foo = `tail -1 $data_path/changelog.0.mfs`;
         chomp($foo);
         if ($n ne $foo) {
            system("$mfsserver restart");
            open (FH,"<$data_path/metadata.mfs.back") or die $!;
            binmode(FH);
            while (sysread(FH, $buf, 1024)) {
                syswrite($client, $buf, length($buf));
            }
            close(FH) or die $!;
         }
     } else {
        close $client;
     }
   }
   close $client;
}


on the metalogger server:


#!/usr/bin/perl
use strict;
use IO::Socket;

my $mfslogger = '/usr/sbin/mfsmetalogger';
my $data_path = "/var/lib/mfs";
my $host = "mfsmaster";
my $port = 7990;
my ($kidpid, $handle, $buf, $c, $last_line);

$last_line = `tail -1 $data_path/changelog_ml.0.mfs`;

$handle = IO::Socket::INET->new(Proto     => "tcp",
                                PeerAddr  => $host,
                                PeerPort  => $port)
         or die "can't connect to port $port on $host: $!";

$handle->autoflush(1);
die "can't fork: $!" unless defined($kidpid = fork());
if ($kidpid) {
    open (FH,">$data_path/metadata_ml.mfs.back") or die $!;;
    binmode(FH);
    $c = 0;
    while (sysread($handle, $buf, 1024)) {
        syswrite(FH, $buf, length($buf));
        $c = $c+1;
    }
    close(FH);
    if ($c) {
        unlink glob("$data_path/changelog_ml*");
        system("touch $data_path/changelog_ml.0.mfs");
        exec("$mfslogger $ARGV[0]");
    }
    kill("TERM", $kidpid);  
}
else {
    print $handle "meta:$last_line\n";
    print $handle "close\n";
}