Manual Chapter :
Common Elements for
Monitors Reference
Applies To:
Show Versions
BIG-IP LTM
- 15.0.1, 15.0.0
Common Elements for
Monitors Reference
In the short description, briefly describe the purpose and
intent of the information contained in this topic.
Name | No default | Provides a name for the
monitor. |
Description | No default | Provides a description of the
monitor. |
Type | Selected monitor
type | Specifies the type of monitor
you are creating. |
Import
Settings Parent
Monitor | Selected predefined or
user-defined monitor | Specifies the selected
predefined or user-defined monitor. |
Interval | 5 | Specifies, in seconds, the
frequency at which the system issues the monitor check when either the resource is
down or the status of the resource is unknown. The default value is 5 seconds. F5 Networks recommends that when you configure this option
and the Up Interval
option, whichever value is greater should be a multiple of the lesser value to
allow for an even distribution of monitor checks among all
monitors. |
Interval | 10 | Specifies, in seconds, the
frequency at which the system issues the monitor check when either the resource is
down or the status of the resource is unknown. The default value is 10 seconds. F5 Networks recommends that when you configure this option
and the Up Interval
option, whichever value is greater should be a multiple of the lesser value to
allow for an even distribution of monitor checks among all
monitors. |
Interval | 30 | Specifies, in seconds, the
frequency at which the system issues the monitor check when either the resource is
down or the status of the resource is unknown. The default value is 30 seconds. F5 Networks recommends that when you configure this option
and the Up Interval
option, whichever value is greater should be a multiple of the lesser value to
allow for an even distribution of monitor checks among all
monitors. |
Interval | 10 | Specifies, in seconds, the
frequency at which the system issues the monitor check when either the resource is
down or the status of the resource is unknown. The default value is 10 seconds. |
Interval | 30 | Specifies, in seconds, the
frequency at which the system issues the monitor check when either the resource is
down or the status of the resource is unknown. The default value is 30 seconds. |
Interval | 30 | Specifies, in seconds, the
frequency at which the system issues the monitor check. The default value is
30 seconds. |
Interval | 90 | Specifies, in seconds, the
frequency at which the system issues the monitor check when either the resource is
down or the status of the resource is unknown. The default value is 90 seconds. |
Up Interval | Disabled | Specifies, in seconds, the
frequency at which the system issues the monitor check when the resource is up. The
enabled default value is 0
(zero), which specifies that the system uses the value of the interval option whether
the resource is up or down. F5 Networks recommends that when you
configure this option and the Interval option, whichever value is greater should be a multiple
of the lesser value to allow for an even distribution of monitor checks among all
monitors. |
Time Until Up | 0 | Delays the marking of a pool
member or node as up for the specified number of seconds after receiving the first
correct response. When this attribute is set to 0 (the default value), the BIG-IP
system marks the resource as up immediately after receiving the first correct
response. |
Timeout | 16 | Specifies the number of
seconds in which the target must respond to the monitor request. The default is
16 seconds. If the
target responds within the set time period, the target is considered to be up. If the
target does not respond within the set time period, the target is considered to be
down. The Timeout value should be three times the Interval value, plus one
second. |
Timeout | 30 | Specifies the number of
seconds in which the target must respond to the monitor request. The default is
30 seconds. If the
target responds within the set time period, the target is considered to be up. If the
target does not respond within the set time period, the target is considered to be
down. |
Timeout | 31 | Specifies the number of
seconds in which the target must respond to the monitor request. The default is
31 seconds. If the
target responds within the set time period, the target is considered to be up. If the
target does not respond within the set time period, the target is considered to be
down. The Timeout value should be three times the Interval value, plus one
second. |
Timeout | 91 | Specifies the number of
seconds in which the target must respond to the monitor request. The default is
91 seconds. If the
target responds within the set time period, the target is considered to be up. If the
target does not respond within the set time period, the target is considered to be
down. The Timeout value should be three times the Interval value, plus one
second. |
Timeout | 90 | Specifies the number of
seconds in which the target must respond to the monitor request. The default is
90 seconds. If the
target responds within the set time period, the target is considered to be up. If the
target does not respond within the set time period, the target is considered to be
down. The Timeout value should be three times the Interval value. |
Timeout | 120 | Specifies the number of
seconds in which the target must respond to the monitor request. The default is
120 seconds. If the
target responds within the set time period, the target is considered to be up. If the
target does not respond within the set time period, the target is considered to be
down. The Timeout value should be three times the Interval value. |
Timeout | 120 | Specifies the number of
seconds in which the target must respond to the monitor request. The default is
120 seconds. If the
target responds within the set time period, the target is considered to be up. If the
target does not respond within the set time period, the target is considered to be
down. The Timeout value should be four times the Interval value. |
Timeout | 180 | Specifies the number of
seconds in which the target must respond to the monitor request. The default is
180 seconds. If the
target responds within the set time period, the target is considered to be up. If the
target does not respond within the set time period, the target is considered to be
down. The Timeout value should be three times the Interval value. |
Probe Interval | 1 | Specifies, in seconds, the
frequency at which the system probes the host server. The default is 1 second. |
Probe Timeout | 5 | Specifies the number of
seconds after which the system times out the probe request to the system. The default
is 5 seconds. |
Probe Attempts | 3 | Specifies the number of times
that the system attempts to probe the host server, after which the system considers
the host server down or unavailable. The default value is 3 . |
Ignore Down Response | No | Specifies that the monitor
allows more than one probe attempt per interval. The default is No . |
Community | Public | Specifies the community name
that the system must use to authenticate with the host server through SNMP. The
default value is public .
Note that this value is case sensitive. |
Version | v1 | Specifies the version of SNMP
that the host server uses. The default is V1 . |
Agent Type | UCD | Specifies the SNMP agent
running on the monitored server. The default is UCD (UC-Davis). |
CPU Coefficient | 1.5 | Specifies the coefficient that
the system uses to calculate the weight of the CPU threshold in the dynamic ratio
load balancing algorithm. |
CPU Threshold | 80 | Specifies the maximum
acceptable CPU usage on the target server. |
Memory Coefficient | 1.0 | Specifies the coefficient that
the system uses to calculate the weight of the memory threshold in the dynamic ratio
load balancing algorithm. |
Memory Threshold | 70 | Specifies the maximum
acceptable memory usage on the target server. |
Disk Coefficient | 2.0 | Specifies the coefficient that
the system uses to calculate the weight of the disk threshold in the dynamic ratio
load balancing algorithm. |
Disk Threshold | 90 | Specifies the maximum
acceptable disk usage on the target server. |
Variables | No default | Presents text fields for
specifying unique variable names and value pairs (which represent coefficient and
threshold values for other types of data, such as user metrics) and a list containing
existing variable definitions that the monitor uses. |
Manual Resume | No | Specifies whether the system
automatically changes the status of a resource to Enabled at the next successful
monitor check. The default is No .If you set this option to Yes , you must manually re-enable
the resource before the system can use it for load balancing
connections. |
Mode | Passive | Specifies the data transfer
process (DTP) mode. The default is Passive . |
Mode | UDP | Specifies the protocol that
the monitor uses to communicate with the target object. The default is UDP . |
MQTT Version | 3.1.1 | Specifies the protocol version
that the monitor will use to communicate with the monitoring object. The default is
3.1.1 . |
Client ID | No default | Specifies the Client ID that
the monitor will send to communicate with the monitoring object. |
Client Certificate | None | For TLS and SIPS modes only, specifies a client
certificate that the monitor sends to the target SSL server. The default is
None . |
Client Key | None | For TLS and SIPS modes only, specifies a key
for a client certificate that the monitor sends to the target SSL server. The default
is None . |
Additional Accepted Status
Codes | None | Specifies the additional SIP
status codes that the monitor uses to determine target status. The default is
None . The monitor always marks the target up in response to status code 200 OK . |
Additional Rejected Status
Codes | Status Code List | This list functions
identically to the Additional Accepted
Status Codes list, except that the monitor treats the list items as
error codes, rather than success codes, and so marks the target down. |
Rejected Status Code List | No default | |
Header List | No default | Specifies one or more headers
that the monitor recognizes. |
SIP Request | No default | Type the request line of the
SIP message, specifying a complete SIP request line minus the trailing \r\n characters. The system uses
the response code to determine whether the server is up or down. The monitor performs
a simple, customized query to a SIP server. The monitor does not establish
connections, perform hand-shaking, or process SIP traffic or requests. It only sends
a request to a server and looks at the response code and (aside from matching the
response to the request) ignores the rest of the response. As a result, this monitor
does not support requests such as INVITE , because the monitor does not enter into a dialog. |
Send String | GET / | Specifies the text string that
the monitor sends to the target object. You must include \r\n at the end of a non-empty send
string. The default setting is GET
/\r\n , which retrieves a default HTML file for a web site. To retrieve
a specific page from a web site, specify a fully-qualified path name, for example:
GET
/www/siterequest/index.html\r\n . When the send string specifies HTTP/1.0 or HTTP/1.1 , the monitor checks
the result code before indicating the monitor as up. Additionally, the server
response code must include a 200
status code, regardless of the receive-string content, in order for the monitor
to mark the server as up. The monitor marks the server as down for any other
response, without further processing. When the send string does not specify HTTP/1.0 or HTTP/1.1 , the monitor uses
HTTP/0.9 and makes
no response code checks. Search string matches on the received reply can
further affect the result. When you create a new TCP, HTTP, or HTTPS monitor in version
10.2.0 and later, you must include a return and new-line entry ( \r\n ) at the end of a non-empty
send string, for example GET
/\r\n instead of GET
/ . If you do not include \r\n at the end of the send
string, the TCP, HTTP, or HTTPS monitor fails. When you include a host in a send
string, you must duplicate the return and new-line entries (\r\n\r\n ), for example,
"GET / HTTP/1.1\r\nHost:
server.com\r\n\r\n" or "GET / HTTP/1.1\r\nHost:
server.com\r\nConnection: close\r\n\r\n" . |
Send String | No default | Specifies the text string that
the monitor sends to the target object. |
Send String | No default | Specifies the SQL statement
that the monitor runs on the target. A sample is: SELECT * FROM <db_name> . This
is an optional setting. If you do not specify a send string, the monitor simply tries
to establish a connection with the target. If the monitor is successful, the system
marks the target up. If the system cannot establish the connection, then it marks the
target down. |
Receive String | No default | Specifies the regular
expression representing the text string that the monitor looks for in the returned
resource. The most common receive expressions contain a text string that is included
in an HTML file on your site. The text string can be regular text, HTML tags, or
image names, and the associated operation is not case-sensitive. The only monitors
that support regular expression matching are HTTP, HTTPS, TCP, and UDP monitors. If you do not specify both a Send
String and a Receive
String , the monitor performs a simple service check and connect
only. |
Receive String | No default | Specifies the response the
monitor expects from the target, when the target receives the send string. This is an
optional setting, and is applicable only if you configure the Send String
setting. If you do not specify both a Send String and a Receive String , the monitor
performs a simple service check and connect only. |
Receive Disable String | No default | Use a Receive String value together with
a Receive Disable String
value to match the value of a response from the origin web server and create one of
three states for a pool member or node: Up (Enabled) , when only Receive String matches the response, or when both Receive String and Receive Disable String match the
response; Up (Disabled) ,
when only Receive Disable
String matches the response; or Down , when neither Receive String nor Receive Disable String matches the
response. If you choose to set the Reverse setting to Yes , the Receive Disable String option
becomes unavailable and the monitor marks the pool, pool member, or node
Down when the test is
successful. |
User Name | No default | Specifies the user name, if
the monitored target requires authentication. When creating tmsh, if there is no password security, you
must use blank strings ("") for the User Name and Password settings. Example: tmsh create ltm monitor http
test-http-pwd password "" . This does not apply to the GUI; do not type
double quotes ("") for the Password
field. |
Password | No default | Specifies the password, if the
monitored target requires authentication. When creating tmsh, if there is no password security, you
must use blank strings ("") for the User Name and Password settings. Example: tmsh create ltm monitor http
test-http-pwd password "" . This does not apply to the GUI; do not type
double quotes ("") for the Password
field. |
Secret | No default | Specifies the secret the
monitor needs to access the resource. |
NAS IP Address | No default | Specifies the network access
server’s IP address (NAS IP address) for a RADIUS monitor. |
Database | No default | Specifies the name of the
database that the monitor tries to access, for example, sales or hr . |
Connection String | No default | Specifies the name of the
database that the monitor tries to access, for example, sales or hr . An
example for this entry is as follows, where you specify the IP address for the
node being monitored, the port for the node being monitored, and the name for the
database: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=%node_ip%)(PORT=%node_port%))
(CONNECT_DATA=(SID=<db name>)) (SERVER=dedicated)) |
Reverse | No | Instructs the system to mark
the target resource down when the test is successful. This setting is useful, for
example, if the content on your web site home page is dynamic and changes frequently,
you might want to set up a reverse ECV service check that looks for the string
Error . A match for this
string means that the web server was down. You can use Reverse only if you configure both
Send String and
Receive
String . |
Transparent | No | Specifies whether the monitor
operates in transparent mode. A monitor in transparent mode uses a path through the
associated pool members or nodes to monitor the aliased destination (that is, it
monitors the Alias
Address -Alias Service
Port combination specified in the monitor). The default is No . |
Receive Row | No default | Specifies the row in the
database where the specified Receive
String should be located. This is an optional setting, and is
applicable only if you configure the Send String and the Receive String settings. |
Receive Column | No default | Specifies the column in the
database where the specified Receive
String should be located. This is an optional setting, and is
applicable only if you configure the Send String and the Receive String settings. |
Count | 0 | Specifies how the system
handles open connections for monitor instances. The default is 0 (zero). By default, when you
assign instances of this monitor to a resource, the system keeps the connection to
the database open. This functionality allows you to assign multiple instances to the
database while reducing the overhead that multiple open connections could cause. The
Count option allows you
to determine the number of instances for which the system keeps a connection open.
|
Alias Address | *All Addresses | Specifies an alias IP address
for the monitor to check, on behalf of the pools or pool members with which the
monitor is associated. The default setting is *All Addresses . If the health check
for the alias address is successful, the system marks all associated objects up. If
the health check for the alias address is not successful, then the system marks all
associated objects down. |
Alias Service Port | *All Ports | Specifies an alias port or
service for the monitor to check, on behalf of the pools or pool members with which
the monitor is associated. The default setting is *All Ports . If the health check for
the alias port or service is successful, the system marks all associated objects up.
If the health check for the alias port or service is not successful, then the system
marks all associated objects down. |
Query Name | No default | Specifies a query name for the
monitor to use in a DNS query, for example, www.siterequest.com . |
Query Type | a | Specifies the type of DNS
query that the monitor sends. The default value is a . This setting provides the
following options.
|
Aggregate Dynamic Ratios | None | Specifies how the system
combines the module values to create the proportion (score) for the load balancing
operation. The score represents the module's estimated capacity for handing traffic.
Averaged values are appropriate for downstream Web Accelerator or Application
Security Manager virtual servers. The default is None , meaning that the system does
not use the scores in the load balancing operation. |
Debug | No | Specifies whether the monitor
sends error messages and additional information to a log file created and labeled
specifically for this monitor. The default setting is No , which specifies that the system
does not redirect error messages and additional information related to this monitor.
The Yes setting specifies
that the system redirects error messages and additional information to the /var/log/<monitor_type>_<ip_address>.<port>.log
file. |
Method | POST | Displays the method the
monitor uses to contact the server. The setting is POST . You cannot modify the
method. |
URL | /scripts/F5Isapi.dll | Specifies the URL that the
monitor uses. The default is /scripts/f5Isapi.dll . |
Command | GetCPUInfo, GetDiskInfo,
GetOSInfo | Specifies the command that the
system uses to obtain the metrics from the resource. See the documentation for the
resource for information on available commands. The default is GetCPUInfo, GetDiskInfo, GetOSInfo .
When using the GetWinMediaInfo command with a
WMI monitor, MicrosoftWindows Server 2003 and MicrosoftWindows Server 2008 require
the applicable version of Windows Media Services to be installed on each
server. |
Metrics | LoadPercentage, DiskUsage,
PhysicalMemoryUsage:1.5, VirtualMemoryUsage:2.0 | Specifies the performance
metrics that the commands collect from the target. The default is LoadPercentage, DiskUsage,
PhysicalMemoryUsage:1.5, VirtualMemoryUsage:2.0 . |
Agent | Mozilla/4.0 (compatible: MSIE 5.0;
Windows NT) | Displays the agent for the
monitor. The default agent is Mozilla/4.0 (compatible: MSIE 5.0; Windows NT) . You cannot modify the
agent. |
Post | RespFormat=HTML | Displays the mechanism that
the monitor uses for posting. The default is RespFormat=HTML . You cannot change
the post format for WMI monitors. |
Pool Name | No default | Requires the name of an
existing pool. |
Protocol Version | 1 | Specifies which version of the
GPRS Tunneling protocol the monitor uses. |
Adaptive | Disabled | Specifies whether adaptive
response time monitoring is enabled for this monitor.
|
Allowed Divergence | Relative, 25% | Specifies the type of
divergence used when the Adaptive setting is enabled (check box selected). In typical cases,
if the monitor detects three consecutive probes that miss the latency value you set,
the system marks the pool member or node as down. There are two options:
|
Adaptive Limit | 200 milliseconds | Specifies the maximum number
of milliseconds that the latency of a monitor probe can exceed the mean latency of a
monitor probe, for the service being probed. This value applies regardless of the
Allowed Divergence
setting value. For example, when the Adaptive setting is enabled (check box selected) with a value set to
500 , the monitor probe
latency cannot exceed 500 milliseconds, even if that value is below the value of the
Allowed Divergence
setting. Setting an adaptive monitor's adaptive-limit below the value of the
db variable bigd.adaptive.default_noise_floor behaves as though the limit is the
same as the noise floor . By
default this is 100ms . |
Sampling Timespan | 300 seconds (5
minutes) | Specifies the length, in
seconds, of the probe history window that the system uses to calculate the mean
latency and standard deviation of a monitor probe. For example, when the Adaptive setting is enabled (check
box selected) with a value set to 300
seconds (that is five minutes), then the BIG-IP system uses the last
five minutes of probe history to determine the mean latency and standard deviation of
a probe. |
