How-to write Perl script for MongoDB

> db.foo.insert({"x":new Date(2010,0,24,9,23,34)});              
> db.foo.insert({"x":new Date(2010,0,26,9,23,34)});
> db.foo.insert({"x":new Date(2010,0,27,9,23,34)});
> db.foo.insert({"x":new Date(2010,0,30,9,23,34)});
> db.foo.insert({"x":new Date(2010,1,02,9,23,34)});
>
> db.foo.find();                                       
{ "_id" : ObjectId("4d65bbec3ebb3cfc9ca664e0"), "x" : "Sun Jan 24 2010 09:23:34 GMT+0800 (CST)" }
{ "_id" : ObjectId("4d65bbf23ebb3cfc9ca664e1"), "x" : "Tue Jan 26 2010 09:23:34 GMT+0800 (CST)" }
{ "_id" : ObjectId("4d65bbf53ebb3cfc9ca664e2"), "x" : "Wed Jan 27 2010 09:23:34 GMT+0800 (CST)" }
{ "_id" : ObjectId("4d65bbf93ebb3cfc9ca664e3"), "x" : "Sat Jan 30 2010 09:23:34 GMT+0800 (CST)" }
{ "_id" : ObjectId("4d65bc023ebb3cfc9ca664e4"), "x" : "Tue Feb 02 2010 09:23:34 GMT+0800 (CST)" }
>
> db.foo.find({"x":{$lt:new Date(2010,0,27,9,23,34)}});
{ "_id" : ObjectId("4d65bbec3ebb3cfc9ca664e0"), "x" : "Sun Jan 24 2010 09:23:34 GMT+0800 (CST)" }
{ "_id" : ObjectId("4d65bbf23ebb3cfc9ca664e1"), "x" : "Tue Jan 26 2010 09:23:34 GMT+0800 (CST)" }
>
> db.foo.find({"x":{$gt:new Date(2010,0,27,9,23,34)}});
{ "_id" : ObjectId("4d65bbf93ebb3cfc9ca664e3"), "x" : "Sat Jan 30 2010 09:23:34 GMT+0800 (CST)" }
{ "_id" : ObjectId("4d65bc023ebb3cfc9ca664e4"), "x" : "Tue Feb 02 2010 09:23:34 GMT+0800 (CST)" }
>

 

 

#!/usr/bin/perl

002

003	use strict;

004	use warnings;

005	use Getopt::Std;                                 # Parm passing routine

006	use MongoDB;

007	use Time::Local;

008

009	format HEADER =

010	------------------------------------------------------------------------------

011	Syntax : $0 -h vipname -p portnum -u usage

012

013

Options:

014

015	-h vipname

016	-p portnum  - default is 27017

017

-u usage

018

019	------------------------------------------------------------------------------

020

.

021

022	my $hostname;

023	my $portnum;

024	my $dbconn;

025	my $dbadmin;

026	my $dbcollection;

027

028	# ---------------------

029

# Main

030	# ---------------------

031

032	&do_opts();

033	&db_connect();

034	&get_stats();

035	&db_disconnect();

036

037	sub do_opts {

038	#--------------------------------------------------------------------------

039	# Split the options and load variables

040	#--------------------------------------------------------------------------

041

042	# Exempt these varaibles from needing to be declared

043	use vars  '$opt_h','$opt_p','$opt_u';

044

045	my $returncode = getopts('h:pu') ;

046

047	&do_help if (defined $opt_u or $returncode != 1 );

048	&do_help if (! $opt_h);

049

050	$hostname          = $opt_h;

051	$portnum           = 27017 || $opt_p;

052

}

053

054	sub db_connect {

055	$dbconn    = MongoDB::Connection->new(host => "$hostname:$portnum");

056	$dbadmin   = $dbconn->admin;

057

}

058

059	sub db_disconnect {

060

}

061

062	sub do_help {

063	#--------------------------------------------------------------------------

064	# Give help screen and exit

065	#--------------------------------------------------------------------------

066	$~ = "HEADER";

067

write;

068

&quit(0);

069

}

070

071	sub quit {

072

exit;

073

}

074

075	sub get_stats {

076

077	my $result = $dbadmin->run_command({serverStatus => 1});

078	#my $result = $dbadmin->run_command({'serverStatus' => 1, 'repl' => 2});      #didn't work with 2 parameters

079	#my $result = $dbadmin->get_collection('$cmd')->find_one(Tie::IxHash->new('serverStatus' => 1, 'repl' => 2));   #works, but complex syntax

080

081	print "current : $result->{connections}->{current}\n";

082

083	print "resident : $result->{mem}->{resident}\n";

084	print "mapped : $result->{mem}->{mapped}\n";

085	print "virtual : $result->{mem}->{virtual}\n";

086

087	print "accesses : $result->{indexCounters}->{btree}->{accesses}\n";

088	print "hits : $result->{indexCounters}->{btree}->{hits}\n";

089	print "misses : $result->{indexCounters}->{btree}->{misses}\n";

090	print "resets : $result->{indexCounters}->{btree}->{resets}\n";

091

092	print "flushes : $result->{backgroundFlushing}->{flushes}\n";

093	print "total_ms : $result->{backgroundFlushing}->{total_ms}\n";

094	print "average_ms : $result->{backgroundFlushing}->{average_ms}\n";

095	print "last_ms : $result->{backgroundFlushing}->{last_ms}\n";

096

097	print "insert : $result->{opcounters}->{insert}\n";

098	print "query : $result->{opcounters}->{query}\n";

099	print "update : $result->{opcounters}->{update}\n";

100	print "delete : $result->{opcounters}->{delete}\n";

101	print "getmore : $result->{opcounters}->{getmore}\n";

102	print "command : $result->{opcounters}->{command}\n";

103

104	my $lagsec = -1;

105	my $primary_optimeDate;

106	my $primary_time;

107	my $my_optimeDate;

108	my $my_time;

109	$result = $dbadmin->run_command({replSetGetStatus => 1});

110	foreach my $repl ( @{$result->{members}} ) {

111	if ($repl->{stateStr} eq "PRIMARY") {

112	$primary_optimeDate = $repl->{optimeDate};

113

}

114	if (exists($repl->{self}) && $repl->{self} == 1) {

115	$my_optimeDate = $repl->{optimeDate};

116

}

117

}

118

119	#data format:  2011-09-20T21:08:04

120	#print "$primary_optimeDate : $my_optimeDate\n";

121	if($primary_optimeDate =~ /(\d+)-(\d+)-(\d+)T(\d+):(\d+):(\d+)/) {

122	my ($p_sec, $p_min, $p_hour, $p_day, $p_mon,$p_year) = ($6, $5, $4, $3, $2, $1);

123	$p_mon = $p_mon - 1;

124	$p_year = $p_year - 1900;

125	$primary_time = timegm($p_sec, $p_min, $p_hour, $p_day, $p_mon,$p_year);

126

}

127	if($my_optimeDate =~ /(\d+)-(\d+)-(\d+)T(\d+):(\d+):(\d+)/) {

128	my ($m_sec, $m_min, $m_hour, $m_day, $m_mon,$m_year) = ($6, $5, $4, $3, $2, $1);

129	#print "$m_sec, $m_min, $m_hour, $m_day, $m_mon, $m_year\n";

130	$m_mon = $m_mon - 1;

131	$m_year = $m_year - 1900;

132	$my_time = timegm($m_sec, $m_min, $m_hour, $m_day, $m_mon,$m_year);

133

}

134	$lagsec = $primary_time - $my_time if($my_time && $primary_time);

135	print "$primary_time: $my_time\n";

136	print "lagSeconds : $lagsec\n";

137

}

 

 

 

 

 

The script run 2 commands to get the MongoDB status. We can get the same by run db._adminCommand({serverStatus : 1}) and db._adminCommand({replSetGetStatus : 1}) in MongoDB Shell .   Let’s take a look at the output of the later one:

---------------------------------------------------------------

shared:PRIMARY> db._adminCommand({replSetGetStatus : 1});

02

{

03	"set" : "shared",

04	"date" : ISODate("2011-09-22T14:36:40Z"),

05	"myState" : 1,

06	"members" : [

07

{

08	"_id" : 0,

09	"name" : "shared.mongodb.org:27017",

10	"health" : 1,

11	"state" : 2,

12	"stateStr" : "SECONDARY",

13	"uptime" : 28033,

14	"optime" : {

15	"t" : 1316677688000,

16

"i" : 2

17

},

18	"optimeDate" : ISODate("2011-09-22T07:48:08Z"),

19	"lastHeartbeat" : ISODate("2011-09-22T14:36:39Z")

20

},

21

{

22	"_id" : 1,

23	"name" : "shared.mongodb.org:27017",

24	"health" : 1,

25	"state" : 1,

26	"stateStr" : "PRIMARY",

27	"optime" : {

28	"t" : 1316677688000,

29

"i" : 2

30

},

31	"optimeDate" : ISODate("2011-09-22T07:48:08Z"),

32	"self" : true

33

}

34

],

35

"ok" : 1

36

}

---------------------------------------------------------------------------------

By comparing the output of MongoDB Shell command and the result in Perl. We can find that the result in Perl is mapped to a hash value, and the value of the hash may be a value, a hash or a array. It’s very easy to get the value we want. Here are the script output example:

-------------------------------------------------------------------------

./getMongoDBStats.pl -h sharedmongo1.mongodb.com

02	current : 3

03	resident : 33

04	mapped : 1392

05	virtual : 3915

06	accesses : 1

07

hits : 1

08	misses : 0

09	resets : 0

10	flushes : 10508

11	total_ms : 27876

12	average_ms : 2.65283593452608

13	last_ms : 0

14	insert : 0

15

query : 9

16	update : 164909

17	delete : 32

18	getmore : 164897

19	command : 253693

20	1316677688: 1316677688

21	lagSeconds : 0

Of course, it’s a quite simple one for MongoDB administrator. But it’s a good and great start