Oracle iPlanet Web Proxy Server 4.0.14 Administration Guide

Chapter 10 Monitoring Servers

This chapter contains information about ways to monitor your server, including the built-in monitoring tool, and Simple Network Management Protocol (SNMP).

You can use SNMP together with iPlanet management information bases (MIB) and network management software such as HP OpenView to monitor your servers in real-time just as you monitor other devices in your network.

Note –

On Windows, before installing Proxy Server 4 ensure that Windows SNMP components are already installed on your system.

You can view the server’s status in real time by using the statistics feature or the SNMP. If you are using UNIX or Linux, you must configure your Proxy Server for SNMP if you plan to use it.

This chapter contains the following sections:

Monitoring the Server Using Statistics

You can use the statistics feature to monitor your server’s current activity. The statistics show you how many requests your server is handling and how well it is handling these requests. If the interactive server monitor reports that the server is handling a large number of requests, you may need to adjust the server configuration or the system’s network kernel to accommodate the requests. Statistics are disabled by default because gathering statistics adds overhead to the Proxy Server. Enabling statistics causes the server to begin gathering and saving statistics information.

Once you enable statistics, you can view statistics in the following areas:

Connections
DNS
KeepAlive
Cache
Server requests

For a description of the various server statistics for which the interactive server monitor reports the totals, see the Monitor Current Activity page in the online help.

Processing Proxy Server Statistics

A built-in function called stats-xml is used to collect Proxy Server statistics. This function must be enabled to view statistics from the Server Manager or to generate a report using the perfdump function. The stats-xml function is also used to enable profiling, which is a requirement for monitoring statistics through the use of a custom NSAPI function. Enabling statistics and profiling on the server initializes a server function called stats-init in the obj.conf file to begin statistics gathering.

Init profiling="on" fn="stats-init"

This instruction also creates a NameTrans directive that allows you to access statistics from a browser window.

NameTrans fn="assign-name" name="stats-xml" from="(/stats-xml|/stats-xml/.*)

Finally, enabling statistics adds a Service directive to process the stats-xml function when the NameTrans directive is selected

<Object name="stats-xml">

Service fn="stats-xml"

</Object>

Statistics gathering updates an Init function in the obj.conf. Therefore, you must stop and start your server for these changes to take effect.

The following example shows stats-init in the obj.conf file:

Init profiling="on" fn="stats-init" update-interval="5"

You can also designate the following values:

update-interval. The period in seconds between statistics updates. A higher setting (less frequent) will be better for performance. The minimum value is 1; the default value is 5.
profiling. whether to activate NSAPI performance profiling. The default is no, which results in slightly better server performance. However, if you activate statistics through the user interface, profiling is turned on by default.

You can retrieve the stats-xml output using the following URL:

http://computer_name:proxyport/stats-xml/proxystats.xml

This request will return an XML page containing the Proxy Server statistics. Some browsers allow you to view the data within the browser window; others require that you save the data to an external file and view it with an external viewer. The usefulness of this information is not fully apparent without the ability to parse the statistics for different views of the data for analysis. The use of third-party tools can assist in this process. Without a parsing tool, the stats-xml output is best observed through the Server Manager or the perfdump SAF.

Restricting Access to the `stats-xml` Output

You should create an ACL for the /stats-xml URI if you want to limit the users who can view the stats-xml statistics for your server from a browser.

The ACL file must also be referenced in the stats-xml object definition in the obj.conf file. For example, if you created a named ACL for the /stats-xml URI, you would need to reference the ACL file in a PathCheck statement in the object definition as follows:

<Object name="stats-xml">

PathCheck fn="check-acl" acl="stats.acl"

Service fn="stats-xml"

</Object>

Enabling Statistics

You must activate statistics on Proxy Server before you can monitor performance. You can activate statistics through the Server Manager, or by editing the obj.conf and magnus.conf files. Users who create automated tools or write customized programs for monitoring and tuning may prefer to work directly with stats-xml.

Caution –

When you enable statistics/profiling, statistics information is made available to any user of your server.

To Enable Statistics From the Server Manager

Access the Server Manager, and click the Server Status tab.

Click the Monitor Current Activity link.

The Monitor Current Activity page is displayed.

Select the Yes option for Activate Statistics/Profiling to enable statistics.

Click OK.

Click Restart Required.

The Apply Changes page appears.

Click the Restart Proxy Server button to apply the changes.

To Enable Statistics Using `stats-xml`

Under the default object in the obj.conf file, add the following line:

NameTrans fn="assign-name" name="stats-xml" from="
(/stats-xml|/stats-xml/.*)"

Add the following Service function to obj.conf:

<Object name="stats-xml">

Service fn="stats-xml"

</Object>

Add the stats-init SAF to the obj.conf.

Using Statistics

Once you have enabled statistics, you can get a variety of information on how your server instance is running. The statistics are broken up into functional areas.

Displaying Statistics in the Server Manager

This section describes how a subset of the proxystats.xml data can be viewed in the Server Manager.

You can view totals, maximum values, peak numbers, and bar graphs of information pertaining to connections to the Proxy Server, DNS processing, keep-alive values, cache, and server requests.

The following section describe the types of information that may be obtained for each of these areas.

Connection Statistics

The following connection statistics are available from the Server Manager:

Total number of connections
Maximum number of queued connections
Peak number of queued connections
Current number of queued connections
Number of processes

DNS Statistics

The following DNS statistics are available from the Server Manager:

Maximum DNS cache entries
Number of processes
Number of DNS cache hits (also shown as a bar graph)
Number of DNS cache misses (also shown as a bar graph)

Keep-Alive Statistics

The following keep-alive statistics are available from the Server Manager:

Maximum keep-alive connections
Keep-alive timeout
Number of processes
Number of keep-alive hits (also shown as a bar graph)
Number of keep-alive flushes (also shown as a bar graph)
Number of keep-alive refusals (also shown as a bar graph)
Number of keep alive time-outs (also shown as a bar graph)

Server Request Statistics

The following server statistics are available from the Server Manager.

Total number of requests.
Number of bytes received.
Number of bytes sent.
Number of processes.
A breakdown of the requests per HTTP server code (also shown as bar graphs). For example, the HTTP server code 200 indicates a fulfilled request.

To Access statistics

Access the Server Manager, and click the Server Status tab.

Click the Monitor Current Activity link.

Choose the refresh interval from the Select Refresh Interval drop-down list.

The refresh interval is the number of seconds between updates of the statistics information displayed.

Choose the kind of statistics you want displayed from the Select Statistics To Be Displayed drop-down list.

For more information about the types of statistics, see Displaying Statistics in the Server Manager.

Click Submit.

If your server instance is running, and you have enabled Statistics/Profiling, you see a page displaying the kind of statistics you selected. The page is updated every 5-15 seconds, depending upon the value of the refresh interval.

Select the process ID from the drop-down list.

You can view current activity through the Server Manager, but these categories are not fully relevant for tuning your server. The perfdump statistics are recommended for tuning your server. For more information, see the next section.

Monitoring Current Activity Using the perfdump Utility

The perfdump utility is a Server Application Function (SAF) built into Proxy Server that collects various pieces of performance data from the Proxy Server internal statistics and displays them in ASCII text. The perfdump utility enables you to monitor a greater variety of statistics than those available through the Server Manager.

With perfdump, the statistics are unified. Rather than monitoring a single process, statistics are multiplied by the number of processes, which gives you a more accurate view of the server as a whole.

Enabling the `perfdump` Utility

You can enable the perfdump SAF only after you have enabled the stats-xml function.

To Enable the `perfdump` SAF

Add the following object to your obj.conf file after the default object:

<Object name="perf">

Service fn="service-dump"

</Object>

Add the following line to the default object:

NameTrans fn=assign-name from="/.perf" name="perf"

Restart your server software.

Access perfdump by going to http://computer_name:proxyport/.perf.

You can request the perfdump statistics and specify how frequently (in seconds) the browser should automatically refresh. The following example sets the refresh to every 5 seconds:

http://computer_name:proxyport/.perf?refresh=5

Sample `perfdump` Output

The following example shows sample perfdump output

			 
proxyd pid: 6751

iPlanet Web Proxy Server 4.0 B05/02/2005 15:32 (SunOS DOMESTIC)

Server started Thu May 19 13:15:14 2005
Process 6751 started Thu May 19 13:15:14 2005

ConnectionQueue:
-----------------------------------------
Current/Peak/Limit Queue Length            0/1/4096
Total Connections Queued                   1
Average Queue Length (1, 5, 15 minutes)    0.00, 0.00, 0.00
Average Queueing Delay                     0.09 milliseconds

ListenSocket ls1:
------------------------
Address                   http://0.0.0.0:8081
Acceptor Threads          1

KeepAliveInfo:
--------------------
KeepAliveCount        0/256
KeepAliveHits         0
KeepAliveFlushes      0
KeepAliveRefusals     0
KeepAliveTimeouts     0
KeepAliveTimeout      30 seconds

SessionCreationInfo:
------------------------
Active Sessions           1
Keep-Alive Sessions       0
Total Sessions Created    48/128

DiskCacheInfo:
------------------
Hit Ratio               0/0 (  0.00%)
Misses                  0
Cache files at startup  0
Cache files created     0
Cache files cleaned up  0

Native pools:
---------------------------
NativePool:
Idle/Peak/Limit               1/1/128
Work Queue Length/Peak/Limit  0/0/0

Server DNS cache disabled

Async DNS disabled

Performance Counters:
------------------------------------------------
 ..........................Average         Total      Percent

Total number of requests:                      1
Request processing time:    0.2559        0.2559

default-bucket (Default bucket)
Number of Requests:                            1    (100.00%)
Number of Invocations:                         7    (100.00%)
Latency:                    0.2483        0.2483    ( 97.04%)
Function Processing Time:   0.0076        0.0076    (  2.96%)
Total Response Time:        0.2559        0.2559    (100.00%)

Sessions:
----------------------------
Process  Status     Function
6751     response   service-dump

For more information about these parameters, see “Using Statistics to Tune Your Server” on Chapter 2 of the Sun ONE Web Server 6.1 Performance Tuning, Sizing, and Scaling Guide.

Restricting Access to the `perfdump` Output

If you want to limit the users who can view the perfdump statistics for your server from a browser you need to create an ACL for the /.perf URI .

The ACL file must also be referenced in the perf object definition in the obj.conf file. For example, if you created a named ACL for the /.perf URI, you would need to reference the ACL file in a PathCheck statement in the object definition as follows:

<Object name="perf">

PathCheck fn="check-acl" acl="perf.acl"

Service fn="service-dump"

</Object>

Using Performance Buckets

Performance buckets enable you to define buckets and link them to various server functions. Every time one of these functions is invoked, the server collects statistical data and adds it to the bucket. For example, send-cgi and NSServletService are functions used to serve the CGI and Java servlet requests respectively. You can either define two buckets to maintain separate counters for CGI and servlet requests, or create one bucket that counts requests for both types of dynamic content. The cost of collecting this information is little and the impact on the server performance is usually negligible. This information can later be accessed using the perfdump utility.

The following information is stored in a bucket:

Name of the bucket- This name is used for associating the bucket with a function
Description- A description of the functions that the bucket is associated with
Number of requests for this function- The total number of requests that caused this function to be called
Number of times the function was invoked- This number might not coincide with the number of requests for the function because some functions might be executed more than once for a single request
Function latency or the dispatch time- The time used by the server to invoke the function
Function time- The time spent in the function itself

The default-bucket is predefined by the server. It records statistics for the functions not associated with any user-defined bucket.

Configuration

You must specify all configuration information for performance buckets in the magnus.conf and obj.conf files. Only the default bucket is automatically enabled.

First, you must enable performance measurement as described in Monitoring Current Activity Using the perfdump Utility.

The following examples show how to define new buckets in the magnus.conf file:

Init fn="define-perf-bucket" name="acl-bucket" description="ACL bucket"

Init fn="define-perf-bucket" name="file-bucket" description="Non-cached responses"

Init fn="define-perf-bucket" name="cgi-bucket" description="CGI Stats"

This example creates three buckets: acl-bucket, file-bucket, and cgi-bucket. To associate these buckets with functions, add bucket=bucket-name to the obj.conf function for which you wish to measure performance.

Example

PathCheck fn="check-acl" acl="default" bucket="acl-bucket"

...

Service method="(GET|HEAD|POST)" type="*~magnus-internal/*" fn="send-file" bucket="file-bucket"

...

<Object name="cgi">

ObjectType fn="force-type" type="magnus-internal/cgi"

Service fn="send-cgi" bucket="cgi-bucket"

</Object>

Performance Report

The server statistics in buckets can be accessed using the perfdump utility. The performance buckets information is located in the last section of the report returned by perfdump.

The report contains the following information:

Average, Total, and Percent columns give data for each requested statistic.
Request Processing Time is the total time required by the server to process all requests it has received so far.
Number of Requests is the total number of requests for the function.
Number of Invocations is the total number of times that the function was invoked. This value differs from the number of requests in that a function could be called multiple times while processing one request. The percentage column for this row is calculated in reference to the total number of invocations for all of the buckets.
Latency is the time in seconds the Proxy Server uses to prepare for calling the function.
Function Processing Time is the time in seconds Proxy Server spent inside the function. The percentage of Function Processing Time and Total Response Time is calculated with reference to the total Request Processing Time.
Total Response Time is the sum in seconds of Function Processing Time and Latency.

The following example shows sample performance bucket information available through perfdump:

Performance Counters:
------------------------------------------------
                           Average         Total      Percent

Total number of requests:                      1
Request processing time:    0.2559        0.2559

default-bucket (Default bucket)
Number of Requests:                            1    (100.00%)
Number of Invocations:                         7    (100.00%)
Latency:                    0.2483        0.2483    ( 97.04%)
Function Processing Time:   0.0076        0.0076    (  2.96%)
Total Response Time:        0.2559        0.2559    (100.00%)

SNMP Basics

SNMP is a protocol used to exchange data about network activity. With SNMP, data travels between a managed device and a network management station (NMS). A managed device is anything that runs SNMP: hosts, routers, your proxy server, and other servers on your network. The NMS is a system used to remotely manage that network. Usually, the NMS software will provide a graph to display collected data or use that data to make sure the server is operating within a particular tolerance.

The NMS is usually a powerful workstation with one or more network management applications installed. A network management application such as HP OpenView graphically shows information about managed devices, such as your web servers. This information might include which servers in your enterprise are up or down, or the number and type of error messages received. When you use SNMP with a proxy server, this information is transferred between the NMS and the server through the use of two types of agents, the subagent and the master agent.

The subagent gathers information about the server and passes the information to the server’s master agent. Every server, except for the Administration Server, has a subagent.

Note –

After making any SNMP configuration changes, you must click Apply Required, then restart SNMP subagent.

The master agent communicates with the NMS. The master agent is installed with the Administration Server.

You can have multiple subagents installed on a host computer, but only one master agent. For example, if you had Proxy Server, Oracle Directory Server Enterprise Edition, and Oracle Communications Messaging Exchange Server installed on the same host, the subagents for each of the servers would communicate with the same master agent.

Management Information Base

The Proxy Server stores variables pertaining to network management. Variables that the master agent can access are called managed objects. These objects are defined in a tree-like structure called the management information base (MIB). The MIB provides access to the Proxy Servers network configuration, status, and statistics. Using SNMP, you can view this information from the NMS.

The top level of the MIB tree shows that the internet object identifier has four sub-trees: directory, mgmt, experimental , and private . The private subtree contains the enterprises node. Each subtree in the enterprises node is assigned to an individual enterprise, which is an organization that has registered its own specific MIB extensions. An enterprise can then create product-specific subtrees under its subtree. MIBs created by companies are located under the enterprises node. The iPlanet server MIBs are also located under the enterprises node. Each iPlanet server subagent provides an MIB for use in SNMP communication. The server reports significant events to the NMS by sending messages or traps containing these variables. The NMS can also query the servers MIB for data, or can remotely change variables in the MIB. Each iPlanet server has its own MIB. All iPlanet server MIBs are located at

server-root/plugins/snmp

The Proxy Servers MIB is a file called proxyserv40.mib. This MIB contains the definitions for various variables pertaining to network management for the Proxy Server. You can see administrative information about your Proxy Server and monitor the server in real time using the Proxy Server MIB.

Setting Up SNMP

To use SNMP you must have a master agent and at least one subagent installed and running on your system. You need to install the master agent before you can enable a subagent.

The procedures for setting up SNMP are different depending upon your system.

Before you begin, you should verify two things:

Whether your system already running an SNMP agent (an agent native to your operating system)
If so, whether your native SNMP agent support SMUX communication? (If you are using the AIX platform, your system supports SMUX.)

See your system documentation for information about how to verify this information.

Note –

After changing SNMP settings in the Administration Server, installing a new server, or deleting an existing server, you must perform the following steps:

(Windows) Restart the Windows SNMP service or reboot the system.
(UNIX) Restart the SNMP master agent using the Administration Server.

Table 10–1 Overview of procedures for enabling SNMP master agents and subagents


If your server meets these conditions....	...follow these procedures. These are discussed in detail in the following sections.
No native agent is currently running	Start the master agent. Enable the subagent for each server installed on the system.
Native agent is currently running No SMUX No need to continue using native agent	Stop the native agent when you install the master agent for your Administration Server. Start the master agent. Enable the subagent for each server installed on the system.
Native agent is currently running No SMUX Needs to continue using native agent	Install a proxy SNMP agent. Start the master agent. Start the proxy SNMP agent. Restart the native agent using a port number other than the master agent port number. Enable the subagent for each server installed on the system.
Native agent is currently running SMUX supported	Reconfigure the SNMP native agent. Enable the subagent for each server installed on the system.

Using a Proxy SNMP Agent (UNIX)

You need to use a proxy SNMP agent when you already have a native agent running, and you want to use continue using it concurrently with Proxy Server master agent. Before you start, be sure to stop the native master agent. See your system documentation for detailed information.

Note –

To use a proxy agent, you must install it and then start it. You will also have to restart the native SNMP master agent using a port number other than the one the Proxy Server master agent is running on.

This section includes the following topics:

Installing the Proxy SNMP Agent
- Starting the Proxy SNMP Agent
- Restarting the Native SNMP Daemon

Installing the Proxy SNMP Agent

If an SNMP agent is running on your system and you want to continue using the native SNMP daemon, follow the steps in these sections:

To install the Proxy SNMP Agent

Install the SNMP master agent.

See Installing the SNMP Master Agent.

Install and start the proxy SNMP agent and restart the native SNMP daemon.

See Using a Proxy SNMP Agent (UNIX).

Start the SNMP master agent.

See Enabling and Starting the SNMP Master Agent.

Enable the subagent.

See Enabling the Subagent.

To install the SNMP proxy agent, edit the CONFIG file, located in plugins/snmp/sagt in the server root directory. Add the port that the SNMP daemon will listen to. This file should also include the MIB trees and traps that the proxy SNMP agent will forward.

The following example shows a CONFIG file.

AGENT AT PORT 1161 WITH COMMUNITY public
SUBTREES       1.3.6.1.2.1.1, 
               3.6.1.2.1.2,
               1.3.6.1.2.1.3,
               1.3.6.1.2.1.4,
               1.3.6.1.2.1.5,
               1.3.6.1.2.1.6,
               1.3.6.1.2.1.7,
               1.3.6.1.2.1.8
FORWARD ALL TRAPS;

Starting the Proxy SNMP Agent

To start the proxy SNMP agent, at the command prompt, type:

# sagt -c CONFIG&

Restarting the Native SNMP Daemon

After starting the proxy SNMP agent, restart the native SNMP daemon at the port you specified in the CONFIG file. To restart the native SNMP daemon, at the command prompt, type

# snmpd -P port-number

where port-number is the port number specified in the CONFIG file. For example, on the Solaris platform, using the port in the previously mentioned example of a CONFIG file, you would type:

# snmpd -P 1161

Reconfiguring the SNMP Native Agent

If your SNMP daemon is running on AIX, it supports SMUX. For this reason, you do not need to install a master agent. However, you do need to change the AIX SNMP daemon configuration.

AIX uses several configuration files to screen its communications. You must edit the snmpd.conf file so that the SNMP daemon accepts the incoming messages from the SMUX subagent. For more information, see the online manual page for snmpd.conf. Add a line to this file to define each subagent.

For example, you might add this line to the snmpd.conf:

smux 1.3.6.1.4.1.1.1450.1 ““ IP-address net-mask

IP_address is the IP address of the host the subagent is running on, and net_mask is the network mask of that host.

Note –

Do not use the loopback address 127.0.0.1. Use theactual IP address instead.

Installing the SNMP Master Agent

To configure the SNMP master agent, you must install the Administration Server instance as the root user. However, even a non-root user can accomplish basic SNMP tasks, such as MIB browsing, on a web server instance by configuring the SNMP subagent to work with the master agent.

To Install the Master SNMP Agent

Check whether an SNMP daemon (snmpd) is running on port 161.
- If no SNMP daemon is running, go to Installing the SNMP Master Agent.
- If an SNMP daemon is running, make sure you know how to restart it and which MIB trees it supports. Then, kill its process.

In the Administration Server, click the Set SNMP Master Agent Trap link in the Global Settings tab.

Type the name of the system that is running your network management software.

Type the port number at which your network management system listens for traps. (The well-known port is 162.)

For more information on traps, see Configuring Trap Destinations.

Type the community string you want to use in the trap.

For more information on community strings, see Configuring the Community String.

Click OK.

In the Administration Server, click the Set SNMP Master Agent Community link in the Global Settings tab.

Type the community string for the master agent.

Choose an operation for the community.

Click New.

Enabling and Starting the SNMP Master Agent

The operation of the master agent is defined in an agent configuration file named CONFIG. You can edit the CONFIG file using the Server Manager, or you can edit the file manually. You must install the master SNMP agent before you can enable the SNMP subagent.

If a bind error message appears similar to System Error: Could not bind to port, when restarting the master agent, use ps -ef | grep snmp to check if magt is running. If it is running, use the command kill -9 pid to end the process. The CGIs for SNMP will then start working again.

This section includes the following topics:

Starting the Master Agent on Another Port

The Administration Interface will not start the SNMP master agent on ports other than 161.

To Manually Start the Master Agent on Another Port

Specify the desired port in the /server-root/plugins/snmp/magt/CONFIG file .

Run the start script as follows:

cd /server-root/proxy-admserv

./start -shell /server-root/plugins/snmp/magt/magt

/server-root/plugins/snmp/magt/CONFIG

/server-root/plugins/snmp/magt/INIT

The master agent will then start on the desired port. The user interface will be able to detect that the master agent is running.

Manually Configuring the SNMP Master Agent

To Configure the Master SNMP Agent Manually

Check whether an SNMP daemon (snmpd) is running on port 161.

If an SNMP daemon is running, make sure you know how to restart it and which MIB trees it supports. Then kill its process.

Edit the CONFIG file located in plugins/snmp/magt in the server root directory.

(Optional) Define sysContact and sysLocation variables in the CONFIG file.

Editing the Master Agent CONFIG File

To configure the master SNMP agent manually

Check to see if there is an SNMP daemon (snmpd) running on port 161.

If an SNMP daemon is running, make sure you know how to restart it and which MIB trees it supports. Then kill its process.

Edit the CONFIG file located in plugins/snmp/magt in the server root directory.

(Optional) Define sysContact and sysLocation variables in the CONFIG file.

Defining `sysContact` and `sysLocation` Variables

The sysContact and sysLocation entries in the CONFIG file specify the sysContact and sysLocation MIB-II variables. The strings for sysContact and sysLocation in this example are enclosed in quotes. Any string that contains spaces, line breaks, tabs, and so on must be in quotes. You can also specify the value in hexadecimal notation.

The following example shows a CONFIG file with sysContract and sysLocation variables defined:

COMMUNITY public

ALLOW ALL OPERATIONS

MANAGER nms2

SEND ALL TRAPS TO PORT 162

WITH COMMUNITY public

INITIAL sysLocation "Server room

987 East Cannon RoadMountain View, CA 94043 USA"INITIAL sysContact "Jill Dawsonemail: jdawson@example.com"

Configuring the SNMP Subagent

You can configure the SNMP subagent to monitor your server.

To Configure the SNMP Subagent

Access the Server Manager, and click the Server Status tab.

Click the Configure SNMP Subagent link.

The Configure SNMP Subagent page is displayed.

Type the name and domain of the server in the Master Host field.

Type the Description of the server, including operating system information.

Type the Organization responsible for the server.

Type the absolute path for the server in the Location field.

Type the name of the person responsible for the server and the person’s contact information in the Contact field.

Select On to Enable the SNMP Statistics Collection.

Click OK.

Click Restart Required.

The Apply Changes page appears.

Click the Restart Proxy Server button to apply the changes.

Starting the SNMP Master Agent

Once you have installed the SNMP master agent, you can start it manually or by using the Administration Server.

To Start the SNMP Master Agent Manually

To start the master agent manually, type the following command at the command prompt:

# magt CONFIG INIT&

The INIT file is a nonvolatile file that contains information from the MIB-II system group, including system location and contact information. If INIT does not already exist, starting the master agent for the first time will create it. An invalid manager name in the CONFIG file will cause the master agent start-up process to fail.

To start a master agent on a nonstandard port, use one of two methods:

Method one: In the CONFIG file, specify a transport mapping for each interface over which the master agent listens for SNMP requests from managers. Transport mappings allow the master agent to accept connections at the standard port and at a nonstandard port. The master agent can also accept SNMP traffic at a nonstandard port. The maximum number of concurrent SNMP is limited by your target system’s limits on the number of open sockets or file descriptors per process. The following example shows a transport mapping entry:

TRANSPORT extraordinary SNMP

OVER UDP SOCKET

AT PORT 11161

After editing the CONFIG file manually, you should start the master agent manually by typing the following command at the command prompt:

# magt CONFIG INIT&

Method two: Edit the /etc/services file to allow the master agent to accept connections at the standard port as well as a nonstandard port.

To start the SNMP Master Agent Using the Administration Server

From the Administration Server, click the Control SNMP Master Agent link on the Global Settings tab.

Click Start.

You can also stop and restart the SNMP master agent from the Control SNMP Master Agent page.

Configuring the SNMP Master Agent

Once you have enabled the master agent and enabled a subagent on a host computer, you need to configure the host’s Administration Server. In this configuration, you specify community strings and trap destinations.

Configuring the Community String

A community string is a text string that an SNMP agent uses for authorization. A network management station sends a community string with each message it sends to the agent. The agent can then verify whether the network management station is authorized to get information. Community strings are not concealed when sent in SNMP packets. Strings are sent in ASCII text.

You can configure the community string for the SNMP master agent from the Set SNMP Master Agent Community page in the Administration Server. You also define which SNMP-related operations a particular community can perform. From the Administration Server, you can also view, edit, and remove the communities you have already configured.

Configuring Trap Destinations

An SNMP trap is a message the SNMP agent sends to a network management station. For example, an SNMP agent sends a trap when an interface’s status has changed from up to down. The SNMP agent must know the address of the network management station so it knows where to send traps. You can configure this trap destination for the SNMP master agent from Proxy Server. You can also view, edit, and remove the trap destinations you have already configured. When you configure trap destinations using Proxy Server, you are actually editing the CONFIG file.

Enabling the Subagent

After you have installed the master agent that comes with the Administration Server, you must enable the subagent for your server instance before you attempt to start it. For more information, see Installing the SNMP Master Agent. You can use the Server Manager to enable the subagent.

To stop the SNMP function on UNIX or Linux platforms, you must stop the subagent first, then the master agent. If you stop the master agent first, you might not be able to stop the subagent. If that happens, restart the master agent, stop the subagent, then stop the master agent.

To enable the SNMP subagent, use the Configure SNMP Subagent page in the Server Manager, and start the subagent from the Control SNMP Subagent page. For more information, see the corresponding sections in the online help.

Once you have enabled the subagent, you can start, stop or restart it from the Control SNMP Subagent page or the Services Control Panel for Windows.

Note –

After making any SNMP configuration changes, you must click Apply Required, then restart SNMP subagent.

Understanding SNMP Messages

GET and SET are two types of messages defined by SNMP. GET and SET messages are sent by a network management station (NMS) to a master agent. You can use these messages with the Administration Server.

SNMP exchanges network information in the form of protocol data units (PDUs). These units contain information about variables stored on the managed device, such as the web server. These variables, also known as managed objects, have values and titles that are reported to the NMS as necessary. Protocol data units sent by the server to the NMS are known as traps. The following examples show the use of GET, SET, and trap messages in communication initiated by the NMS or by the server.

NMS-initiated Communication. The NMS either requests information from the server or changes the value of a variable store in the server’s MIB. For example:

The NMS sends a message to the Administration Server master agent. The message might be a request for data (a GET message), or an instruction to set a variable in the MIB (a SET message).
The master agent forwards the message to the appropriate subagent.
The subagent retrieves the data or changes the variable in the MIB.
The subagent reports data or status to the master agent, and then the master agent forwards the GET message back to the NMS.
The NMS displays the data textually or graphically through its network management application.

Server-initiated Communication. The server subagent sends a message or trap to the NMS when a significant event has occurred. For example:
The subagent informs the master agent that the server has stopped.
The master agent sends a message or trap reporting the event to the NMS.
The NMS displays the information textually or graphically through its network management application.

Chapter 10 Monitoring Servers

Monitoring the Server Using Statistics

Processing Proxy Server Statistics

Restricting Access to the stats-xml Output

Enabling Statistics

To Enable Statistics From the Server Manager

To Enable Statistics Using stats-xml

Using Statistics

Displaying Statistics in the Server Manager

To Access statistics

Monitoring Current Activity Using the perfdump Utility

Enabling the perfdump Utility

To Enable the perfdump SAF

Sample perfdump Output

Restricting Access to the perfdump Output

Using Performance Buckets

Configuration

Performance Report

SNMP Basics

Management Information Base

Setting Up SNMP

Using a Proxy SNMP Agent (UNIX)

Installing the Proxy SNMP Agent

To install the Proxy SNMP Agent

Starting the Proxy SNMP Agent

Restarting the Native SNMP Daemon

Reconfiguring the SNMP Native Agent

Installing the SNMP Master Agent

To Install the Master SNMP Agent

Enabling and Starting the SNMP Master Agent

Starting the Master Agent on Another Port

To Manually Start the Master Agent on Another Port

Manually Configuring the SNMP Master Agent

To Configure the Master SNMP Agent Manually

Editing the Master Agent CONFIG File

To configure the master SNMP agent manually

Defining sysContact and sysLocation Variables

Configuring the SNMP Subagent

To Configure the SNMP Subagent

Starting the SNMP Master Agent

To Start the SNMP Master Agent Manually

To start the SNMP Master Agent Using the Administration Server

Configuring the SNMP Master Agent

Configuring the Community String

Configuring Trap Destinations

Enabling the Subagent

Understanding SNMP Messages

Restricting Access to the `stats-xml` Output

To Enable Statistics Using `stats-xml`

Enabling the `perfdump` Utility

To Enable the `perfdump` SAF

Sample `perfdump` Output

Restricting Access to the `perfdump` Output

Defining `sysContact` and `sysLocation` Variables