NANNY (8)
tool to monitor status of services in a cluster
SYNOPSIS
nanny [-t|--interval= ARG ] [-I|--ipvsadm= ARG ]
[-M|--method= ARG ] [-U|--loadcmd= ARG ]
[-n|--nodaemon] [-c|--nofork] [--norun] [-p|--port= ARG ]
[-a|--reentrytime= ARG ] [-h|--server= ARG ] [-v|--verbose]
[-V|--virtaddress= ARG ] [-w|--weight= ARG ] [-S|--scale= ARG ]
[-s|--send_string= ARG ] [-x|--expect_string= ARG ]
[-T|--suppress] [-?|--help] [--usage]
Using nanny to monitor failover services:
nanny [-t|--interval= ARG ] [-U|--loadcmd= ARG ]
[-n|--nodaemon] [-c|--nofork] [--norun] [-p|--port= ARG ]
[-h|--server= ARG ] [-v|--verbose] [-V|--virtaddress= ARG ]
[-s|--send_string= ARG ] [-x|--expect_string= ARG ]
[-R|--startup= ARG ] [-D|--shutdown= ARG ]
[-T|--suppress] [-?|--help] [--usage]
DESCRIPTION
nanny is a daemon used by pulse to monitor the running status of
the specified services on clustered servers. This tool has NO error checking
and should not be run without the direct supervision of pulse!
OPTIONS
-t ARG |--interval= ARG
ARG specifies the number of seconds to wait between connection attempts to the
server/service.
-I ARG |--ipvsadm= ARG
This s the path to the ipvsadm tool, which is
normally /usr/sbin/ipvsadm. This parameter is not used
in failover service monitoring.
-M ARG |--method= ARG
This option specifies the routing method for the real server
(this parameter is not used in monitoring failover services).
Allowable choices are:
g - Use gatewaying (direct routing).
m - Use masquerading (network access translation, or NAT).
t - Use ipip encapsulation (tunneling).
-U|--loadcmd= ARG
Command to get remote load average and/or perform file transfers with
(rup, rsh, ssh).
-n|--nodaemon
Normally, nanny runs as a daemon but with this option
runs in the foreground. When running in this mode, nanny sends all
output to STDOUT instead of to syslog.
-c|--nofork
This mode forces nanny to disassociate from the terminal, but don't fork
off into a daemon.
--norun
Runs nanny in a test mode.
-p|--port= ARG
Port for nanny to monitor on real server to check for service availability.
If omitted, port 80 (http) is assumed.
-a|--reentrytime= ARG
The number of seconds a failed service must remain alive before allowing the
service/node back into the cluster. The main purpose of this time delay is to
avoid having a service or node ping-ponging. As a general rule of thumb, if
the service is available uninterupted for 60-120 seconds, then it is generally
ok to let it back into the cluster. This parameter is ignored for failover
services.
-S|--scale= ARG
This is a factor used to adjust the sensitivity of the real server loading
algorythm. By increasing this factor, the CPU load on the server must be much
higher before the weighting of the server will be affected in the LVS routing
table. This parameter is ignored for failover services.
-h|--server= ARG
This is the IP address of the server that is to be monitored. MUST
BE SPECIFIED.
-v|--verbose
Give *lots* of debugging information to either syslog or STDOUT.
-V|--virtaddress= ARG
This is the virtual IP address of the service to be monitored (fos), or
the address of the real server (lvs).
-w|--weight= ARG
The relative weighting of the real servers can be adjusted by changing this
setting to a higher number. For example, if one server has a weighting of 1
and another one has a weight of 2, the second one will get twice as many
requests redirected to it. The user-assigned weight of the server is adjusted
dynamically based the cpu load average and by the scale factor. This
parameter is ignored for failover services.
-s|--send_str= ARG
Optional text string to send to the port in order to test whether the
service is functioning. Length is limited to 255 printable, quoteable
text characters (\\n, \\r, \\t, \\\\, and \\' are also permitted).
If the send_str option is omitted altogether, then no attempt to
send data will occur EXCEPT if port = 80 and expect_str is also omitted,
in which case a web service is assumed and an http test string
will be sent and expected
(for backwards compatibility with earlier releases of piranha).
If both --send_str and --expect_str are specified, then the send_str
string will be sent first, before the expect_str string is received
and tested. If neither are specified (and port is not 80), then the
service will only be tested by the success and/or failure of connecting to
the port. No other I/O will be performed.
-x|--expect_str= ARG
Optional text
response string expected from the port in order to test whether the
service is functioning. Length is limited to 255 printable, quotable
text characters (\\n, \\r, \\t, \\\\, and \\' are also permitted).
If expect_str="*", then any characters are accepted (but SOMETHING
must be received). This is different than not specifying any expect
string, which means do not even attempt the receive operation.
If this option is omitted then no attempt to
receive data will occur EXCEPT if port = 80 and send_str is also
omitted, in which case a web service
is assumed and an http test string will be sent and expected (for backwards
compatibility with earlier releases of piranha).
If both --send_str and --expect_str are specified, then the send_str
string will be sent first, before the expect_str string is received
and tested. If neither are specified, the service will only be tested
by the success and/or failure of connecting to the port. No other I/O
will be performed.
-T|--suppress
Suppress translation of '\\' characters in send/expect strings. Try
this if your send/expect strings are not being handled properly. It
will prevent the nanny program from performing its own translations.
-R|--startup= ARG
This parameter is mandatory for monitoring failover services, and
must be omitted for monitoring real servers. The specified value is the
command or script to execute to start the monitored service and
a single optional parameter separated by a space.
Failover services are started and stopped by nanny as part of
the failover process, and nanny determines whether the service
it is monitoring is a failover service (instead of a virtual server)
by the presence or absence of this parameter.
The command used should be repeatable; meaning that it should
be harmless (other than a possible returned error value) to
execute the command multiple times in a row.
-D|--shutdown= ARG
This parameter is mandatory for monitoring failover services, and
must be omitted for monitoring real servers. The specified value is the
command or script to execute to stop the monitored service and a
single optional parameter separated by a space.
Failover services are started and stopped by nanny as part of
the failover process, and nanny determines whether the service
it is monitoring is a failover service (instead of a virtual server)
by the presence or absence of this parameter.
The command used should be repeatable; meaning that it should
be harmless (other than a possible returned error value) to
execute the command multiple times in a row.
-?|--help
Shows a verbose usage listing.
--usage
Outputs a terse argument summary.
SEE ALSO
AUTHOR
Erik Troan <ewt@redhat.com>
Keith Barrett <kbarrett@redhat.com>
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