url_response IM Configuration

This article is for probe versions 4.3 or later.
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url_response_IM
This article describes the configuration concepts and procedures for setting up the URL Endpoint Response Monitoring (url_response) probe. Create a profile and set up the monitoring parameters, which when breached generates alarms and QoS messages.
 
This article is for probe versions 4.3 or later.
 
The following diagram outlines the process to configure the url_response probe:
url_response_IM_Configuration
url_response_IM_Configuration
 
Contents
 
 
 
Verify Prerequisites
Verify that required hardware and software is available before you configure the probe. For more information, see url_response (URL Endpoint Response Monitoring) Release Notes.
Configure General Properties
You can configure the log properties of the probe to define how to maintain the log information. You can also, configure the global properties of the profile, for example, when to perform the monitoring and the severity of alarms.
 
Follow these steps:
 
  1. Navigate to the 
    Setup
     tab.
  2. Update the following information:
    •  
      Log Level: 
      specifies the level of details that are written to the log file.
      Default: 0-Fatal
      Log as little as possible during normal operation to minimize disk consumption, and increase the amount of detail when debugging.
    •  
      Log size: 
      specifies the size of the probe log file to which the internal log messages of the probe are written. When this size is reached, new log file entries are added and the older entries are deleted.
      Default: 100
    •  
      Send alarm on each sample: 
      allows you to generate an alarm for each sample. If this checkbox is not selected, the probe generates alarms based on the average of number of samples as specified in the 
      Average over _ samples
       field specified in 
      Profiles properties,  Alarms
       tab.
    •  
      User Agent: 
      specifies the user agent string that identifies your browser and provides certain system details to servers hosting the web sites to visit. If you do not provide any value, the hard-coded string NimBUS/2.0 is used, simulating that the client is a Nimsoft client. 
      To learn more about User Agent strings, refer http://msdn.microsoft.com/en-us/library/ms537503.aspx.  
  3. Click 
    OK.
     
Create a Profile
You can create a profile and define the monitoring parameters.
 
Follow these steps:
 
  1. Navigate to the 
    Profiles 
    tab.
  2. Right click in the list and select 
    New.
    The 
    Profile properties - <New Profile>
     dialog appears.
  3. Complete the following information:
    •  
      Group: 
      defines the group to which the profile will be added. Select an existing group from the drop down or add a  group by selecting the 
      <New Group> 
      option.
    •  
      Profile: 
      defines the name of the profile. CA recommends you to use a descriptive name as the profile name is used in alarm messages.
    •  
      URL: 
      defines the URL of the web page that you want to monitor.
      You can click on the 
      Test URL 
      button to test whether the probe is able to fetch the URL data. It returns response time and number of bytes returned in case of successful connection. In case of connection failure, it shows message “Couldn’t resolve hostname”. The response message box also contains a 
      View Source 
      button allowing you to see the HTML source of the selected page.
    •  
      (From url_response 4.41) Additional Header:
       specifies the comma separated URL header key-value pairs in the 
      Key: Value
       format. For example, x-api-key1: 8DB54440-B550, x-api-key2: 8DB54440-B551, and so on.
    •  
      Virtual hostname: 
      defines the virtual host and IP address of the system hosting the URL that you want to monitor. The virtual host appears in the 
      Select variable 
      dialog, using the 
      $host
       variable. If the virtual hostname is not specified, the robot name is displayed in alarms for $host, by default.
    •  
      Check interval (sec.): 
      specifies the time interval after which the URL is checked.
      : Reduce this interval to generate alarms and QoS frequently. A shorter interval can also increase the system load.
      Default: 300
    •  
      Timeout (sec.): 
      specifies the time interval for which the probe waits for the complete web page to be loaded. If the page takes longer to load, you will not get response time data. For example, if the 
      Timeout 
      is set to 20 seconds and 
      Retries before failure 
      is set to 3, then, the probe retries and waits for 20 seconds. After executing all the 3 retries, the probe generates an alarm, on failure.
      Default: 30
    •  
      Retries before failure: 
      specifies the number of attempts to access the URL before reporting it as a failure. These retries are executed within a single check interval. For example, if the 
      Check interval
       is set to 300 seconds and 
      Retries before failure 
      is set to 3, then, the probe executes all the 3 retries in 300 seconds and generates an alarm, on failure.
      Default: 3
    •  
      Ignore connection time: 
      allows you to ignore the connection time while calculating total response time.
  4. Navigate to the 
    Alarms 
    tab, and complete the following information to send alarm messages when the specified threshold is breached:
     On Unified Service Management (USM), the alarms display under a Device ID created by the probe, which is the destination URL without the port number.
     
    •  
      Alarm Properties: 
      allows you to send alarm messages when the specified threshold is breached.
    •  
      Max Page Load in time (ms): 
      specifies the maximum time in milliseconds to load a webpage, which when breached, an alarm is generated.
      •  
        Max Page Load in time 
        value should be less than the 
        Timeout
         value specified in 
        General properties 
        section.
      • Alarm message is sent if the 
        average
         value of the last samples exceeds the specified threshold. The number of samples that are specified in the 
        Average over < > samples
         field is used to calculate the average value.
      Default: 8000
    •  
      Min Page load in time (ms): 
      defines a minimum time in milliseconds to load a webpage. An alarm is generated if the page takes less than this specified time to load.
    •  
      Time to first byte (ms): 
      defines the time for page to load the first byte.
    •  
      Time to last byte (ms): 
      defines the time for page to load the last byte.
    •  
      TCP connection time (ms): 
      defines the minimum time required to connect to TCP.
    •  
      Threshold Fetch Bytes: 
      defines a threshold for the number of bytes fetched per second. Select the check box and specify the threshold value in the text box, which when breached, an alarm is generated.
    •  
      DNS resolution time (ms): 
      specifies the minimum time required for DNS resolution.
      Default: 20
    •  
      Download time (ms): 
      defines the minimum time required for downloading the web content.
    •  
      Redirect time (ms): 
      defines the minimum time required for web page redirection.
    •  
      Average over < > samples: 
      allows you to specify the number of QoS metric samples for defining a graph. This is the number of samples used to calculate the average value to be compared with the threshold value. Select the check box and enter the value in the text box. You can open the graph by right-clicking a profile in the profile-list and selecting 
      View samples
      Default: 5 
      : You must specify a value greater than one for number of samples. If the probe finds this field value as zero, it takes five as the default value.
    •  
      Look for substring in page content: 
      defines a string to search for in the web page content once it is loaded.
       Select the 
      Use regexp content matching 
      option if you use regular expressions in the string and start and end the string with a "/".
    •  
      Use regexp content matching: 
      allows you to apply regular expression while matching instead of the proper sub string.
    •  
      Dump File Content
      •  
        On file content alarm condition: 
        allows you to dump contents of the page to a file if contents of the page are not as expected, or the page returns an error code. When the profile is saved, you can right click on it from the list and select 
        View file dumps 
        to view the dump files.
    •  
      Alarm when substring
      : allows you to enable or disable alarm messages when a sub string is specified in 
      Look for substring in page content 
      field. For example, when you specify "test" in 
      Look for substring in page content 
      field and mark 
      Alarm when substring 
      check box,
       
      the probe generates alarm messages when the specified string is found.
      •  
        found/not found: 
        allows you to determine if an alarm message should be issued when the sub string is 
        found
         or 
        not found
        .
      •  
        Retry page fetch on alarm situation: 
        allows you to specify the condition to retry fetching a page when an alarm situation occurs.
        •  
          Number of retries: 
          defines the number of times the page content should be fetched before the alarm is generated.
        •  
          Retry timeout (sec.): 
          defines the time to retry for fetching the URL contents.
  5. Click on 
    Alarm Override 
    to select the alarm messages to be used for each monitoring parameter. You can also mention the 
    Subsystem
     id and the message for 
    Alarm delayed overrides
    .
  6. Navigate to 
    QoS
     tab to select the following criteria to generate the QoS:
    •  
      Response time: 
      response time data of a monitored URL.
    •  
      Time to first byte: 
      time required to fetch the first byte.
    •  
      Time to last byte: 
      time required to fetch the last byte.
    •  
      Sub-string found: 
      sub-string is found or not found in the URL page. If the sub-string is found in the URL page then value is one, else value is null.
    •  
      Fetch time bytes per second: 
      the number of bytes fetched from the URL per second.
    •  
      DNS resolution time: 
      time for DNS resolution.
    •  
      TCP connect time: 
      time required to establish TCP connection.
    •  
      Fetched size in bytes: 
      number of URL bytes fetched from the URL at each interval.
    •  
      Download time:
       time required to download the URL contents.
    •  
      Redirect time: 
      time required to redirect the URL.
  7. Navigate to the 
    SSL Settings
     tab and update the following information to enable the SSL certificate verification and provide the certification bundle path:
    •  
      Use SSL: 
      allows you to use
       
      the SSL certificate verification.
    •  
      Peer Verification: 
      allows the probe to enable peer verification. Peer is the certification authority that issues SSL certificates.
      •  
        Certification Authority Bundle Path: 
        specifies the certification bundle path for SSL verification. The bundle contains certificates of all the issuing authorities and can be obtained from 
        http://curl.haxx.se/docs/caextract.html
        to add a certificate to the bundle, see https://www.watchguard.com/help/docs/ssl/2/en-US/Content/FAQs/add_bundled_certificates_faq.html. The SSL certificate bundle path should point to a file that has one or more certificates to verify the peer.
    •  
      Host Verification: 
      allows the probe to enable host verification.
      •  
        Host Verification Level: 
        There are two following levels of host verification:
        •  
          Loose
          : host name entered in the Server address field is NOT verified against the Common Name (CN) attribute appearing in the SSL certificate. The verification checks if the IP address or host name points to the same server.
        •  
          Strict
          : host name that is entered in the Server address field is verified against the CN attribute appearing in the SSL certificate. If the host name does not match with the CN field, the session request gets rejected.
  8. Navigate to 
    Schedules 
    tab
     
    and defines how to schedule the profile execution on specific date and time, based on the rules specified in 
    Schedules
    . Use this option, if you do NOT want to use the 
    Check interval
     time and want to refine the time interval of running the profile. For example, run your profile to monitor the URL only on Wednesday mornings at 8:00 A.M. The following options are available for the scheduling.
    •  
      rules: 
      profile is scheduled to run according to the rules described in 
      Schedules
      .
    •  
      exceptions: 
      profile is NOT scheduled to run according to the rules described in 
      Schedules
  9. Navigate to the 
    Authentication
     tab, and update the following information to configure the user authentication type.
    •  
      Windows NT authentication: 
      enables the Windows Integrated Authentication. Proxy settings are fetched from the registry as saved by Internet Explorer. If you select this option, the probe supports monitoring of only the following metrics:
      • Response time
      • Fetch time in bytes per second
      • Fetch size in bytes
      • Substring found
      When the probe is hosted on the Linux environment, you can select the Authentication type from the drop-down list.
       
      •  
        Impersonate user:
         specifies the 
        User
         name and 
        Password
         used by the probe when logging on the server. The specified user proxy settings are then retrieved from the registry as saved by Internet Explorer. 
      •  
        User Authentication:
         specifies the
         User 
        name and
         Password 
        used on the web server host used for accessing the web page.
    •  
      Authentication Type: 
      defines the following types of authentication for accessing the URL using proxy server.
      •  
        Basic: 
        specifies a basic HTTP authentication that allows you to define a username and password for accessing the URL. The Basic authentication used in HTTP is based on plain text.
      •  
        NTLM: 
        specifies if NT LAN Manager (NTLM) security protocol is required to access the URL in a Windows network. NTLM uses three messages to authenticate a client in a connection-oriented or connectionless environment. First, the client establishes a network connection to the server and sends a NEGOTIATE_MESSAGE to advertise its attributes. Next, the server responds with CHALLENGE_MESSAGE that should be used to establish the identity of the client. Finally, the client responds to the challenge with an AUTHENTICATE_MESSAGE. If the integrity is desired, a fourth additional message is sent.
      •  
        DIGEST: 
        This method uses a client and server to exchange credentials over HTTP. The password is combined with other bits of information to create an MD5 hash which is then sent to the server to authenticate.
      •  
        GSSNEGOTIATE: 
        This authentication is used when a client application wants to authenticate to a remote server, but neither end is sure which authentication protocols the other supports.
      •  
        ANYSAFE: 
        specifies if ANYSAFE authentication is used for accessing the URL.
    •  
      Host: 
      defines the host that forwards your URL requests.
    •  
      Port: 
      defines the Proxy http-port.
    •  
      User: 
      defines username to log in the proxy hosts.
    •  
      Password: 
      defines the password corresponding to the proxy login user.
    •  
      Tunneling proxy: 
      allows to tunnel all operations through the HTTP proxy specified. All requests and replies are passed unmodified through the 
      Tunneling proxy
      .
    •  
      User Authentication:
       specifies the
       User 
      name and
       Password 
      used on the web server host used for accessing the web page.
    • When user authentication is required, the probe has the option to supply the username and password. However, this works only when these can be supplied according to the HTTP / HTTPS protocols.
    • When accessing such pages interactively with a web-browser, the web browser asks the user for authentication and passes this on to the server.
    • In a Windows environment, a different user authentication is possible (Windows NT Authentication). This is done by probe impersonating the required user locally before accessing the URL.
  10. Navigate to the 
    SSL Certificate
     tab and update the following information to handle SSL errors, raise alarms related to the expiration dates of server certificates of the URLs, and configure SSL certificates:
    •  
      Ignore SSL Errors: 
      allows you to ignore the SSL errors that occurred during the URL access.
    •  
      Server Certificate within <> days of expiration: 
      raises an alarm if the certificate is due to expire within the specified number of days.
      Default: 0 
    •  
      Certificate expired: 
      allows you to raise an alarm if the SSL certificate associated with the URL has already expired at the time of access.
    •  
      Configure SSL Certificate: 
      allows you to configure the SSL certificate in the system. Consider the following points to configure the SSL certificate:
      • While using basic authentication, the client certificate and private key
         
        should be in the PEM format.
      • For IIS server with basic authentication, the certificate will have to be converted from PFX to PEM. This can be done using OpenSSL.
        • The win32 distribution of OpenSSL can be downloaded from 
          http://www.slproweb.com/products/Win32OpenSSL.html
          .
        • To extract the certificate file (the signed public key) from the PFX file, use the following Open SSL command:
          openssl pkcs12 -in <cert.pfx> -clcerts -nokeys -out <cert.pem>
        • To extract private key from a PFX file and write it to PEM file, use the following OpenSSL command:
          openssl pkcs12 -in <cert.pfx> -ncerts -out <provateKey.pem>
        • Visit 
          http://www.openssl.org/
           for further information on OpenSSL.
        • While using Windows authentication, the client certificate should be in the PFX format. The PFX files contain client certificate and private key, so the probe need not supply the private key separately.
      •  
        Client certificate: 
        specifies the path for the client certificate file location.
      •  
        Client private key: 
        specifies the path for the client private key
         
        file location.
      •  
        Password: 
        defines password associated with the certificate.
  11. Navigate to the 
    Advanced
     tab to override the source of Alarm and QoS messages. If you do not enter a value in 
    Source override
     field for 
    Source used for Quality of Service
    , the robotname of system where probe is deployed is the QoS source. The following variables can be used in these fields:
    •  
      $group: 
      If $group is specified in 
      Source override
       field then $group is replaced by group of URL server in source fields of Alarms and QoS.
    •  
      $host: 
      If $host is specified in 
      Source override
       field, then the $host is replaced by Virtual hostname in source fields of Alarms and QoS. If Virtual hostname is blank, then the $host is replaced by the robot name.
    •  
      $profile: 
      If $profile is specified in 
      Source override
       field, then $profile is replaced by profile of URL server in source fields of Alarms and QoS.
    •  
      $url: 
      If $url is specified in 
      Source override
       field, then $url is replaced by url of URL server in source fields of Alarms and QoS.
      You can also override any text in 
      Source override
       fields with or without variables in both QoS and alarm variables.
  12. Click 
    OK.
     
    The profile appears in the specified group. You can right click on the group to collapse or expand it.
  • If you want to edit a profile, right click on it and select
     Edit.
     
  • If you do not want to use a profile, right click on it and select 
    Delete.
     
  • If you want to rename the profile, right click on it and select 
    Rename. 
    CA recommends you to use a descriptive name as the profile name is used in alarm messages.
  • If you want to move a profile to another group, right click on it, select 
    Move to group 
    and choose the group name from the drop down.
  • If you want to see the webpage for a specific profile, right click on it and select 
    Wizard.
     
Create a Schedule
You can create a specific schedule to define when a profile must be executed. If you do not define a schedule, the profile is executed at an interval of 24 hours, by default. A 
Schedule
 is a definition of an execution period (or execution break, if 
exceptions
 used) with specified days, time from or to and date from or to values.
 
Follow these steps:
 
  1. Right click on the 
    Schedules
     list and select 
    New
    .
    The 
    Edit Schedule
     dialog appears.
  2. Define the parameters to schedule the profile and click 
    OK
  • To copy the attributes of a selected schedule to another, right click on a schedule and select 
    Copy
    .
  • To modify an existing schedule, right click or double-click on a schedule and select 
    Edit
    .
  • To delete an existing schedule, right click on a schedule and select 
    Delete
     
Create Alarm Messages
You can define the alarm messages that you want the user to receive when a specified threshold is breached or cleared.
 
Follow these steps:
 
  1. Navigate to the 
    Messages
     tab.
    The tab lists the pre-defined alarm messages.
  2. Right click on the list and click 
    New.
    The
     Add Message Definition 
    dialog appears.
  3. Update the following field information:
    •  
      Name: 
      defines a unique name for a message from profiles.
    •  
      Text: 
      specifies the alarm message text. You can use variables in the messages.
    •  
      Level: 
      specifies the severity level assigned to the alarm messages.
    •  
      Subsystem: 
      specifies the subsystem_ID of alarms generated by the probe. This subsystem Id is managed by the 
      nas
       probe.
    •  
      Default for: 
      specifies the default alarm message for the type of error.
  4. Click 
    OK.
     
     
  • If you want to edit a message, right click on it and select
     Edit
    .
  • If you do not want to use a message, right click on it and select
     Delete.
     
View URL Response Time
You can right click on an active profile and select
 View samples
 for a graphical representation of the latest response time values measured for the monitored URL.