Chapter 8. Managing your Web server

Managing Your Web Server

Your servers present your company to the world on the Internet and are an integral part of internal operations. To ensure continuous, secure, and efficient operation, Internet Connection Secure Server provides facilities for monitoring and managing your server. This chapter describes how to manage and monitor your servers and includes the following topics:

Simple Network Management Protocol

A network management system is a program that runs continuously and is used to monitor, reflect status of, and control a network. Simple Network Management Protocol (SNMP), a popular protocol for communicating with devices in a network, is the current network management standard. The network devices typically have an SNMP agent and one or more subagents. The SNMP agent talks to the network management station or responds to command line SNMP requests. The SNMP subagent retrieves and updates data and gives that data to the SNMP agent to communicate back to the requester.

The Internet Connection Secure Server provides an SNMP management information base (MIB) and SNMP subagent so you can use any network management system, such as IBM NetView for AIX, TME10 Distributed Monitoring, or HP OpenView, to monitor your server's health, throughput, and activity. The MIB data describes the Web server being managed, reflects current and recent server status, and provides server performance data.

The network management system uses SNMP GET commands to look at MIB values on other machines. It then can notify you if specified threshold values are exceeded. You can affect server performance, by modifying configuration data for a server, to proactively tune or fix server problems before they become server outages.

SNMP commands and protocol

The system usually provides an SNMP agent for each network management station. The user or a programmer sends a GET command to the SNMP agent. In turn, this SNMP agent sends a GET command to retrieve the specified MIB variable values from a subagent responsible for those MIB variables.

The Internet Connection Secure Server provides a subagent that updates and retrieves MIB data. The subagent responds with the appropriate MIB data when the SNMP agent sends a GET command. The SNMP agent communicates the data to the network management station. The network management station can notify you if specified threshold values are exceeded.

The Internet Connection Secure Server SNMP support includes an SNMP subagent that uses Distributed Protocol Interface (DPI) capability. DPI is an interface between an SNMP agent and its subagents.

Object IDs and variable names for the Internet Connection Secure Server MIB

The Internet Connection Secure Server MIB is modeled after the HTTP MIB proposal. MIB layout includes Variable Name, Object ID, Type, and Description.

The following Variable Names and Object IDs are provided for SNMP support with the Internet Connection Secure Server:

EntityDescription

Description: Identifies a server in human-readable form. This read-only value is not customizable.
Object ID: 1.3.6.1.4.1.2.6.120.1.1.1.1.1.1.1
Type: OCTET_STRING
Default value: An appropriate value for your server installation and platform.

EntityObjectID

Description: Identifies a particular server in machine-readable form, providing a globally unique name among other applications and versions. This read-only value is not customizable.
Object ID: 1.3.6.1.4.1.2.6.120.1.1.1.1.1.2.1
Type: OCTET_STRING
Default value: 1.3.6.1.4.1.2.6.120.10.1

EntityContact

Description: Indicates who to contact if a problem or question about this running server arises. It is human-readable and frequently contains the e-mail address of the on-site system administrator responsible for server maintenance. The value for EntityContact may be customized with the WebMasterEmail directive in the httpd.conf file.
Object ID: 1.3.6.1.4.1.2.6.120.1.1.1.1.1.3.1
Type: OCTET_STRING
Default value: webmaster

EntityProtocol

Description: Identifies the exact protocol and its version that a particular server supports. For a Web server, the protocol is HTTP. This read-only identifier is in machine-readable form and is not customizable.
Object ID: 1.3.6.1.4.1.2.6.120.1.1.1.1.1.4.1
Type: OCTET_STRING
Default value: 1.3.6.1.4.1.2.12.1

EntityProtocolVersion

Description: This human-readable string identifies the protocol this server supports and the protocol version. Similar to EntityProtocol. This read-only value is not customizable.
Object ID: 1.3.6.1.4.1.2.6.120.1.1.1.1.1.5.1
Type: OCTET_STRING
Default value: HTTP/1.1

EntityName

Description: This human-readable string provides the name of the host this Web server runs on. The value for EntityName may be customized with the HostName directive in the httpd.conf file. It is read-only and set by system-specific code at server initialization time.
Object ID: 1.3.6.1.4.1.2.6.120.1.1.1.1.1.6.1
Type: OCTET_STRING
Default value: www.raleigh.ibm.com

EntityAddress

Description: This human-readable string provides the IP address of the host this Web server runs on. It is read-only and set by system-specific code at server initialization time.
Object ID: 1.3.6.1.4.1.2.6.120.1.1.1.1.1.7.1
Type: IpAddress
Default value: 0.0.0.0

EntityPort

Description: This human-readable string provides the port number this Web server listens to. It is read-only and set by system-specific code at server initialization time.
Object ID: 1.3.6.1.4.1.2.6.120.1.1.1.1.1.8.1
Type: INTEGER
Default value: 0

EntityType

Description

This machine-readable integer differentiates between several server roles.

Possible values are:

1: Simple or normal HTTP server
2: Proxy server
3: Caching server

It is read-only and set by system-specific code at server initialization time. The information is taken from the httpd configuration file.

Object ID

1.3.6.1.4.1.2.6.120.1.1.1.1.1.9.1

Type

INTEGER

Default value

CurrentThreads

Description: Indicates how many threads the server has currently. The total number of active threads is the sum of the MIB values, applInboundAssociations and applOutboundAssociations. This information is read-only.
Object ID: 1.3.6.1.4.1.2.6.120.1.1.1.1.1.10.1
Type: INTEGER
Default value: 0

MaxThreads

Description: Indicates the maximum number of threads the server can have. To affect server performance, use the MaxActiveThreads directive to modify the value for MaxThreads in the httpd.conf file. This is read-only information.
Object ID: 1.3.6.1.4.1.2.6.120.1.1.1.1.1.11.1
Type: INTEGER
Default value: 0

MinThreads

Description: Indicates the minimum number of threads the server can have. This is read only information.
Object ID: 1.3.6.1.4.1.2.6.120.1.1.1.1.1.12.1
Type: INTEGER
Default value: 1

SummaryRequests

Description: Indicates the total number of request the server received plus the total number of requests the server generated (for example, as a proxy server). This read-only information is updated as the server runs.
Object ID: 1.3.6.1.4.1.2.6.120.1.1.2.1.1.1.1
Type: INTEGER
Default value: 0

SummaryRequestErrors

Description: Indicates the total number of request errors detected by the server. This read-only information is updated as the server runs.
Object ID: 1.3.6.1.4.1.2.6.120.1.1.2.1.1.2.1
Type: INTEGER
Default value: 0

SummaryRequestDiscards

Description: Indicates the total number of requests discarded by the server (for any reason). This read-only information is updated as the server runs.
Object ID: 1.3.6.1.4.1.2.6.120.1.1.2.1.1.3.1
Type: INTEGER
Default value: 0

SummaryResponses

Description: Indicates the total number of responses generated or received by this server. This read-only information is updated as the server runs.
Object ID: 1.3.6.1.4.1.2.6.120.1.1.2.1.1.4.1
Type: INTEGER
Default value: 0

SummaryResponseDiscards

Description: Indicates the total number of responses discarded by the server. This read-only information is updated as the server runs.
Object ID: 1.3.6.1.4.1.2.6.120.1.1.2.1.1.5.1
Type: INTEGER
Default value: 0

SummaryInUnknowns

Description: Indicates the total number of unknown messages received by this server. This read-only information is updated as the server runs.
Object ID: 1.3.6.1.4.1.2.6.120.1.1.2.1.1.6.1
Type: INTEGER
Default value: 0

SummaryInBytes

Description: Indicates the total number of bytes received by this server. This read-only information is updated as the server runs.
Object ID: 1.3.6.1.4.1.2.6.120.1.1.2.1.1.7.1
Type: INTEGER
Default value: 0

SummaryOutBytes

Description: Indicates the total number of bytes sent out by this server. This read-only information is updated as the server runs.
Object ID: 1.3.6.1.4.1.2.6.120.1.1.2.1.1.8.1
Type: INTEGER
Default value: 0

TotalTimeouts

Description: Indicates the total number of timeouts on the Web server. This read-only information is updated as the server runs.
Object ID: 1.3.6.1.4.1.2.6.120.1.1.2.4.0
Type: INTEGER
Default value: 0

LastTimeoutEntityIndex

Description: This value is for future extensibility and provides support for the Application Table. This read-only value is always 1 and is not customizable.
Object ID: 1.3.6.1.4.1.2.6.120.1.1.2.5.0
Type: INTEGER
Default value: 1

LastTimeoutRemoteAddress

Description: Provides the IP address of the machine that timed out last. This read-only value is updated by server code as the server runs.
Object ID: 1.3.6.1.4.1.2.6.120.1.1.2.6.0
Type: IpAddress
Default value: 0.0.0.0

applName

Description: The name that the network service application is known by. This read-only value is not customizable.
Object ID: 1.3.6.1.2.1.27.1.1.2.1
Type: OCTET_STRING
Default value: Internet Connection Server platform

applDirectoryName

Description: The X.500 name for Web server. This read-only value is not customizable and is currently not supported by Internet Connection Secure Server Web server.
Object ID: 1.3.6.1.2.1.27.1.1.3.1
Type: OCTET_STRING
Default value: Not available

applVersion

Description: The version of software the server is running. This human-readable value is read-only and not customizable.
Object ID: 1.3.6.1.2.1.27.1.1.4.1
Type: OCTET_STRING
Default value: 4.2

applUptime

Description: This value is how long the server has been up. This is a read-only value.
Object ID: 1.3.6.1.2.1.27.1.1.5.1
Type: TimeTicks
Default value: 0

applOperStatus

Description

Indicates the operational status of the Web server. The Internet Connection Secure Server sets this value to up at server startup. It is currently a read-only value.

Additional standardized values for this MIB variable include down, halted, congested, and restarting. These values may be used in the future.

Standardized values include:

1: Up - indicates that the server is operational and available.
2: Down - indicates that the Web server is not available.
3: Halted - indicates that the Web server is operational but not available.
4: Congested - indicates that the server is operational but no additional inbound associations can be accommodated.
5: Restarting - indicates that the server is currently unavailable but is in the process of restarting and will be available soon.

Object ID

1.3.6.1.2.1.27.1.1.6.1

Type

INTEGER

Default value

applLastChange

Description: Indicates how long from when the server came up (applUptime) that the applOperStatus changed. Currently this will always be 0 because applOperStatus is only set to up at server startup. This is a read-only value.
Object ID: 1.3.6.1.2.1.27.1.1.7.1
Type: TimeTicks
Default value: 0

applInboundAssociations

Description: Indicates the number of inbound connections currently running or how many threads are processing received requests. This is a read-only value.
Object ID: 1.3.6.1.2.1.27.1.1.8.1
Type: Gauge32
Default value: 0

applOutboundAssociations

Description: Indicates the number of outbound connections that the server is currently handling or how many threads are processing outbound requests. This value is 0 if the server is not acting as a proxy server. This is a read-only value.
Object ID: 1.3.6.1.2.1.27.1.1.9.1
Type: Gauge32
Default value: 0

applAccumulatedInboundAssociations

Description: Indicates the total number of server's inbound connections until this time. This is a read-only value.
Object ID: 1.3.6.1.2.1.27.1.1.10.1
Type: Gauge32
Default value: 0

applAccumulatedOutboundAssociations

Description: Indicates the total number of server's outbound connections until this time. This value is 0 if the server is not acting as a proxy server. This is a read-only value.
Object ID: 1.3.6.1.2.1.27.1.1.11.1
Type: Counter32
Default value: 0

applLastInboundActivity

Description: Indicates the time since applUptime that the last inbound connection was made. This is a read-only value.
Object ID: 1.3.6.1.2.1.27.1.1.12.1
Type: TimeTicks
Default value: 0

applLastOutboundActivity

Description: Indicates the time since applUptime that the last outbound connection was made. This is a read-only value.
Object ID: 1.3.6.1.2.1.27.1.1.13.1
Type: TimeTicks
Default value: 0

applRejectedInboundAssociations

Description: Indicates the total number of requests the server has rejected. This is a read-only value.
Object ID: 1.3.6.1.2.1.27.1.1.14.1
Type: Counter32
Default value: 0

applFailedOutboundAssociations

Description: Indicates the total number of the server's outbound requests that failed. This is a read-only value.
Object ID: 1.3.6.1.2.1.27.1.1.15.1
Type: Counter32
Default value: 0

Note: The timestamp values for the Internet Connection Secure Server MIB variables, applLastChange, applLastInboundActivity, and applLastOutboundActivity, vary from RFC 1565. In RCF 1565, timestamps are relative to sysUpTime. These three Internet Connection Secure Server timestamp values are relative to applUptime.

Creating an e-mail address to receive SNMP problem reports

The Internet Connection Secure Server provides a default e-mail address, webmaster, for the Web server administrator to receive problem reports from SNMP. Use the WebMasterEmail directive to customize the mail address. The typical format for this value is user@rootname. For more information about the WebMasterEmail directive, see "WebMasterEmail - Creating an e-mail address to receive SNMP problem reports".

Enabling SNMP on your NT system

To get a DPI-capable SNMP agent for Windows NT, install the SystemView Agent Developers Toolkit for Windows NT, which can be downloaded from the http://www.software.ibm.com/download/ URL.

Before you start the SystemView snmpd process, you must disable the Microsoft Windows NT SNMP support. The snmpd supports DPI subagents and Microsoft-compliant agents.

To disable the Microsoft Windows NT SNMP support:

From your Windows NT version 4.0 desktop, click on the My Computer icon. From your Windows NT version 3.51 desktop, click on the Main icon.
Click on the Control Panel icon.
Click on the Service icon.
Select SNMP.
For Windows NT version 4.0, click HW Profiles. For Windows NT version 3.51, click Startup.
For Windows NT version 4.0, click Disable. For Windows NT version 3.51, under Startup Type, click Disable.

Note:

If you do not disable the Microsoft Windows NT SNMP support, the Internet Connection Secure Server SNMP subagent will not be able to connect to the snmpd agent.

To configure the SystemView SNMP agent, follow the instructions in "Providing a security password for SNMP".

Providing a security password for SNMP

You can create community names (passwords). The default SNMP community name is public.

Before creating passwords for server communities, configure the SystemView SNMP agent.

From your desktop, click on the SystemView Agent icon.
Click on snmpcfg.
In the SNMP Configuration dialog box, add the community name. For testing purposes, enter public as the community name.
This allows any host in any network to access the SNMP MIB variables. After you have verified that these values work, you can change them according to your requirements.
Check the sva.batch file and ensure that the -dpi option is specified before starting snmpd.

Use the SNMPCommunityName directive to define the password used between the Internet Connection Secure Server DPI subagent and the SNMP agent. The default is public. If you change this value, you must also add the new community name to the SystemView Agent snmpcfg. For more information about the SNMPCommunityName directive, see "SNMPCommunityName - Providing a security password for SNMP".

Enabling and disabling SNMP support

Use the SNMP directive to enable or disable SNMP support. To enable SNMP support, change the SNMP value to on. The default SNMP value is off.

For more information about the SNMP directive, see "Turning the SNMP support on and off from the whttpg command".

Turning the SNMP support on and off from the whttpg command

Use these flags to turn the SNMP support in the Internet Connection Secure Server on and off.

The -snmp flag turns the SNMP support on. The -nosnmp flag turns the SNMP support off.

This overrides what is defined in the httpd.conf file.

For more information about the whttpg command, see "whttpg command".

Monitoring server performance and status

The Internet Connection Server Activity Monitor allows you to display server and network performance and status statistics, and access log entries, without being on the same machine that is running the server. This option provides significantly more information than opening the console window.

In addition, you can use the Performance Monitor built into Windows NT to monitor your server.

Using the Server Activity Monitor function

You do not need to enable or configure the Server Activity Monitor function. By default, the Server Activity Monitor is enabled by the following Service directive in the configuration file:

  Service   /Usage* INTERNAL:UsageFn

To view server statistics, network statistics, and access log entries, use either of the following methods:

Use any browser and specify URL http://your.server.name/Usage/Initial, where your.server.name is the fully qualified name of your host, for example, www.ibm.com.
Click Configuration and Administration Forms on the server Front page. Then click Server Activity Monitor in the System Management section.

The following sections describe the type of information that is available and provide hints and tips on monitoring certain statistics. To update the statistics on a page, click Refresh.

Server activity statistics

Figure 3 shows an example of the server statistics that are displayed on the Basic Status page.

Figure 3. Example of Basic Status page statistics

Hints and Tips:

If the number of idle threads is low, you may need to increase the number of threads that are available to the server.
To monitor server response, use the Response time for local files statistic.
To monitor traffic, use the Requests processed, Bytes received, and Bytes sent statistics.

Network activity statistics

Figure 4 shows an example of the network statistics that are displayed on the Network Status page.

Figure 4. Example of Network Status page statistics

Note:

Incoming and outgoing data values include only data received and sent by the server.

Access log

The access log page displays the 20 most recent entries in the access log. For more information on the access log, go to "Tailoring the logs your server keeps".

Using the Windows NT Performance Monitor

You can select the Internet Connection Secure Server as an object for the Performance Monitor built into Windows NT to monitor errors and performance of your server. The HTTP port used by the server is displayed as the corresponding instance. These are the counters you can select to monitor:

Counter: Definition
CGI requests: The total number of CGI requests processed by the server
Error 200 OK: The total number of requests receiving a 200 response code. This means success.
Error 302: The total number of requests receiving a 302 response code.
Error 401: The total number of requests receiving a 401 response code.
Error 403: The total number of requests receiving a 403 response code.
Error 404: The total number of requests receiving a 404 response code.
Error 407: The total number of requests receiving a 407 response code.
Error 500: The total number of requests receiving a 500 response code.
Error Level 200: The total number of requests receiving a response code in the range 200-299.
Error Level 300: The total number of requests receiving a response code in the range 300-399.
Error Level 400: The total number of requests receiving a response code in the range 400-499.
Error Level 500: The total number of requests receiving a response code in the range 500-599.
GET requests: The total number of GET requests processed by the server.
HEAD requests: The total number of HEAD requests processed by the server.
POST requests: The total number of POST requests processed by the server.
Total ICAPI requests: The total number of requests serviced by the IBM APIs.
Total KBytes received: The number of kilobytes received by the server.
Total KBytes received /sec: The number of kilobytes received by the server per second.
Total KBytes sent: The total number of kilobytes sent by the server.
Total KBytes sent/sec: The number of kilobytes sent by the server per second.
Total requests: The number of requests processed.
Total requests/sec: The number of requests processed per second.

Note: The server must be running so that it can be monitored by the Performance Monitor. If you restart the server, the monitoring will start back up where it left off, but if the server dies, you will have to reset the monitoring to begin again once the server is back up. See the Microsoft Windows NT documentation for more details about how the Performance Monitor works.

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