Hello. In my organization we have multiple Memcached servers that we load balance with IPVS. I needed the ability to service check them and I didn't want to settle for the "connect" and "simpletcp" wouldn't work with the telnet interface or the Memcached protocol. So I added the ability for ldirectord to natively service check a Memcached instance. Once this patch is applied, you will need the Memcached Perl module installed for the service check to function. http://search.cpan.org/~dormando/Cache-Memcached-1.30/ To configure ldirectord to service check Memcached, set the service line to memcached. service = memcached Additionally, you can configure the key value pair to store in Memcached by configuring the request line to "key:value". request = "key:value" If request is not configured, a default of "ldirectord:ldirectord" will be used. I'm open to any comments, or suggestions. Also, if you feel that this feature is beneficial I would appreciate if it was merged into the mainline. Thanks. --- /usr/sbin/ldirectord 2012-04-27 05:40:43.000000000 -0600 +++ /usr/sbin/ldirectord_memcached 2012-12-20 16:08:16.210085669 -0700 @@ -448,7 +448,7 @@ On means no checking will take place and real servers will always be activated. Default is I<negotiate>. -B<service = >B<dns> | B<ftp> | B<http> | B<https> | B<http_proxy> | B<imap> | B<imaps> | B<ldap> | B<mysql> | B<nntp> | B<none> | B<oracle> | B<pgsql> | B<pop> | B<pops> | B<radius> | B<simpletcp> | B<sip> | B<smtp> | B<submission> +B<service = >B<dns> | B<ftp> | B<http> | B<https> | B<http_proxy> | B<imap> | B<imaps> | B<ldap> | B<memcached> | B<mysql> | B<nntp> | B<none> | B<oracle> | B<pgsql> | B<pop> | B<pops> | B<radius> | B<simpletcp> | B<sip> | B<smtp> | B<submission> The type of service to monitor when using checktype=negotiate. None denotes a service that will not be monitored. @@ -498,6 +498,8 @@ =item * Virtual server port is 5060: sip +=item * Virtual server port is 11211: memcached + =item * Otherwise: none =back @@ -554,6 +556,10 @@ The data returned is not checked, only that the answer is one or more rows. This is a required setting. +For a Memcached check, this should be a key value pair in the format: key:value. +This key value pair will try and be stored in the specified Memcached instance. +If not configured, a default key value of ldirectord:ldirectord will be used. + For a simpletcp check, this string is sent verbatim except any occurrences of \n are replaced with a new line character. @@ -570,6 +576,8 @@ For a MySQL check, the receive setting is not used. +For a Memcached check, the receive setting is not used. + B<httpmethod = GET> | B<HEAD> Sets the HTTP method which should be used to fetch the URI specified in @@ -1497,6 +1505,7 @@ $1 eq "imaps" || $1 eq "ldap" || $1 eq "nntp" || + $1 eq "memcached" || $1 eq "mysql" || $1 eq "none" || $1 eq "oracle"|| @@ -1515,6 +1524,7 @@ "http_proxy, " . "imap, imaps, " . "ldap, nntp, " . + "memcached, " . "mysql, none, " . "oracle, " . "pop, pops, " . @@ -1817,6 +1827,7 @@ if ($port eq 3306) { return "mysql"; } if ($port eq 5060) { return "sip"; } if ($port eq 5432) { return "pgsql"; } + if ($port eq 11211) { return "memcached"; } return "none"; } @@ -1848,6 +1859,7 @@ if ($service eq "mysql") { return 3306; } if ($service eq "sip") { return 5060; } if ($service eq "pgsql") { return 5432; } + if ($service eq "memcached") { return 11211; } return undef; } @@ -2729,6 +2741,8 @@ $$r{num_connects} = 0 if (check_oracle($v, $r) == $SERVICE_UP); } elsif ($$v{service} eq "simpletcp") { $$r{num_connects} = 0 if (check_simpletcp($v, $r) == $SERVICE_UP); + } elsif ($$v{service} eq "memcached") { + $$r{num_connects} = 0 if (check_memcached($v, $r) == $SERVICE_UP); } else { $$r{num_connects} = 0 if (check_none($v, $r) == $SERVICE_UP); } @@ -3640,6 +3654,52 @@ return $SERVICE_DOWN; } +sub check_memcached +{ + use Cache::Memcached; + + my ($v, $r) = @_; + my $port = ld_checkport($v, $r); + + &ld_debug(2, "Checking $$v{service}: server=$$r{server} port=$port with a connect/select timeout of: $$v{negotiatetimeout}"); + + my $memcached = new Cache::Memcached { + 'servers' => [ $$r{server} . ":" . $port ], + 'connect_timeout' => $$v{negotiatetimeout}, + 'select_timeout' => $$v{negotiatetimeout}, + }; + + my @key_val = split(":", $$r{request}); + $key_val[0] =~ s#^/##; + + if (!defined($key_val[0]) or !defined($key_val[1])) { + &ld_debug(2, "The request line is not configured correctly, or at all."); + &ld_debug(2, "Use the format request = \"key:value\" when using memcached as the service."); + &ld_debug(2, "Using a default key:value of ldirectord:ldirectord"); + + $key_val[0] = "ldirectord"; + $key_val[1] = "ldirectord"; + } + + &ld_debug(2, "Trying to set key: $key_val[0] value: $key_val[1] in memcached"); + + if ($memcached->set($key_val[0], $key_val[1])) { + &ld_debug(2, "Setting key: $key_val[0] value: $key_val[1] in memcached was successfull"); + + $memcached->disconnect_all; + + service_set($v, $r, "up", {do_log => 1}); + return $SERVICE_UP; + } + + &ld_debug(2, "Setting key: $key_val[0] value: $key_val[1] in memcached failed"); + + $memcached->disconnect_all; + + service_set($v, $r, "down", {do_log => 1}); + return $SERVICE_DOWN; +} + # check_none # Dummy function to check service if service type is none. # Just activates the real server -- To unsubscribe from this list: send the line "unsubscribe lvs-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
