Table Of Contents
Introduction to Process Control
Execution of External Effects in Automations
Configuring and Managing Cisco Info Center Components
Removing a Process Agent From the Network
Creating a Process Control System Configuration
Before You Configure Process Control
Configuring Process Control Agents
Adding Server Names in the Server Editor
Starting the Process Control Agent Manually
Starting Process Control Automatically on Reboot
Defining Processes, Services, and Hosts
Process Definition Description
Service Definition Description
Specifying Process Dependencies
Defining Routing Hosts, Usernames, and Passwords
Example Process Agent Configuration File
Process Control Agent Daemon Command Line Options
Displaying Service Status - nco_pa_status
Starting a Service or Process - nco_pa_start
Stopping a Service or Process - nco_pa_stop
Shutting Down a Process Control Agent - nco_pa_shutdown
Adding a New Service or Process to a Running PAD - nco_pa_addentry
Process Control
This chapter describes the components, configuration, and management utilities associated with the Cisco Info Center Process Control system. It includes the following sections:
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Introduction to Process Control
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Introduction to Process Control
The Cisco Info Center Process Control system performs two primary tasks:
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Note
The information in this chapter is for advanced users who might want to modify the process control agents as installed and configured during the Cisco Info Center installation. If you are not familiar with the files and scripts that are used to implement process control, it is advisable to maintain the configuration using the Cisco Info Center configuration utility, nco_config.
Execution of External Effects in Automations
Process Control is responsible for the execution of external effects specified in automations. An automation does not execute programs by itself. It sends a request to a local Process Control agent, which forwards the request to the Process Control agent running on the specified host. The remote Process Control agent then executes the requested program.
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Configuring and Managing Cisco Info Center Components
Process Control allows you to configure remote processes to simplify the configuration and management of Cisco Info Center components such as Cisco Info Servers, Cisco Info Mediators, and gateways. It consists of the following elements:
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The Process Control agents cooperate automatically and understand their own configuration. Process Control agents start remote processes and are capable of keeping those processes running. Processes can be defined as dependent on the starting of a previous process or have timed threshold dependencies. If a managed host is restarted, the Process Control agent restarts local components automatically.
Process Agents
Any Cisco Info Center participating UNIX host must be configured with the Process Control agent daemon. When you configure an Info Server or other Info Center components using the nco_config configuration utility, the Info Server and other components are automatically configured to use Process Control and the host is connected into the Process Control system. Figure 7-1 shows a basic Cisco Info Center configuration consisting of three hosts running Process Control agents.
Figure 7-1 Basic Cisco Info Center Process Control Configuration
Joining the Network
A process agent joins the network by connecting to an existing member. If it tries to connect and fails, it retries after the number of seconds specified in the MaxConnect property in its properties file (agent-name_PA.props). If a process agent loses one of its connections in the network, it waits for the number of seconds specified in the MinConnect property in this file for a reconnection from another process agent. If this does not arrive, it tries to reconnect itself to the node to which it was last connected at the interval specified in the MaxConnect property.
When a process agent receives a request to join the existing network, it allows a proportion of the MinConnect period for the requesting agent to confirm it has joined. This proportion is specified as a percentage between 20% and 80% in the AcceptRatio property.
Removing a Process Agent From the Network
To remove a process agent from the network, stop the service from the Control Panel. Before it leaves the network, the agent notifies the other members and waits for acknowledgement for the time specified in the MaxRingSpeed property. If it does not receive acknowledgement, it leaves the network anyway. In this case, the network is not broken even if that was the intention in removing the agent.
The appropriate values for the MinConnect, MaxRingSpeed, and AcceptRatio properties are a function of network speed. They should be larger for slower networks to allow less stringent recovery criteria.
Process Control Components
Process Control consists of a Process Control agent daemon, an associated configuration file, and utilities to help you manage the Process Control agent and the processes and services configured in Process Control.
Process Control Agents
Process Control agents are programs installed on each host to manage Cisco Info Center processes. Any participating host must have a Process Control agent daemon and associated configuration file installed.
There can be any number of Process Control agents on any number of hosts. Process Control agents can manage any number of processes.
Processes
Processes are programs executed by a Process Control agent on the same machine. Processes must be defined within a service, described next.
A PA Aware process is part of the Process Control configuration and is aware of Process Control. All the features of Process Control, such as process dependencies, can be utilized. The Cisco Info Server, Cisco Info Mediators, and gateways are PA Aware. A process that is not PA Aware can be managed by Process Control, but cannot use all the features of Process Control a PA Aware process can use. The Desktop is not PA Aware. For information about how to set the process type to PA Aware, see Defining Processes.
Sometimes the order in which applications are started is important. You can use Process Control to configure processes to be dependent on each other. For example, a process can be configured to start only after another process has started and completed various startup tasks.
A PA Aware process communicates with the Process Control agent. Once the process has reached the point in its startup when it recognizes itself to be running, it sends a message to the Process Control agent. When the Process Control agent receives this message, it starts dependent processes.
Services
You can use Process Control to configure and manage local and remote processes, and to provide automatic management of those processes. Processes must be defined within services. You can group related processes in a service to make them easier to manage. Once a service is correctly configured, it can be managed by Process Control.
A service is made up of one or more processes executed by Process Control agents. A service can be configured to start up automatically when the Process Control agent starts. Alternatively, it can be started manually.
A service can either be a master or a non-master. When started automatically by Process Control, master services are started before non-master services.
Process Control Utilities
Command line utilities are provided to do the following:
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Creating a Process Control System Configuration
This section describes how to create a new Process Control configuration.
Before You Configure Process Control
Before you start to configure Process Control:
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Once you have determined the complete Cisco Info Center configuration requirements, follow the instructions described in the following sections.
Creating User Groups
By default, the Process Control system uses UNIX user names and passwords to grant access to the Process Control system. Other supported authorization modes can be specified using the -authorization command line option, described in Process Control Management.
To control who can log in, any user who needs access to the Process Control system must be made a member of a UNIX user group called ncoadmin. If this group does not exist, create it and add Process Control users. If you run NIS, NIS+, or some other global information service, this process must be performed by the administrator of that service. See the documentation provided with your operating system for details of creating user groups.
Configuring Process Control Agents
For each Process Control agent you must:
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Adding Server Names in the Server Editor
Using the Server Editor, you must assign a unique server name to each Process Control agent for each host machine. For each Process Control agent:
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The name must end with _PA to identify the server as a Process Control agent in the server editor. For example, if you are installing the Process Control agent on a host machine named sfosys1, the Process Control agent could be named SFOSYS1_PA. By default, the first Process Control agent installed in a configuration is named NCO_PA.
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This enables all Process Control agents on all host machines to connect to each other.
Starting the Process Control Agent Manually
The Process Control agent can be started manually at the command line with the command:
$OMNIHOME/bin/nco_pad -name <process_agent>
where <process_agent> is the name of the Process Control agent.
Starting Process Control Automatically on Reboot
When you install Cisco Info Center, you are prompted to configure automatic startup on system boot. If you choose to configure automatic startup, then the name of a startup script is added to the startup script for the host.
If you choose not to configure automatic startup, then the installation utility places a startup script called nco in the /etc/init.d directory. You can then use the nco script to start and stop the installed Info Server components manually.
When Cisco Info Server starts up automatically or you start it manually, process control is started up and any components that run under process control are run under the control of the process control system.
For information on the nco command, refer to the "Starting a Cisco Info Server Manually" section. and the "Stopping a Cisco Info Server Manually" section.
Defining Processes, Services, and Hosts
To run under Process Control, processes, services, and hosts must be added to the following configuration file:
$OMNIHOME/etc/process_agent_name.conf
The Process Control agent reads this file when it is started to establish configuration settings. The file is made up of definitions, each of which contains various attributes and associated values, for each process, service, and host.
Edit this file directly to add or modify definitions. Maintain the configuration files on all of your hosts to ensure the host configuration information stays synchronized across all of the agents in the configuration.
Note
Defining Processes
You must define the list of processes in the configuration file. An example process definition in the configuration file is shown below:
nco_process `Info Server'
{
Command `$OMNIHOME/bin/nco_objserv -name NCOMS -pa SFOSYS1_PA' run as 0
Host = `sfosys1'
Managed = true
RestartMsg = `The Info Server has been restarted'
AlertMsg = `The Info Server has gone down'
RetryCount = 0
ProcessType = PaPA_AWARE
}Process Definition Description
Table 7-1 contains a description of the process definition information contained in the configuration file.
Table 7-1 Process Definition Description
nco_process `Info Server'
Defines the name of the process. This example is for a Cisco Info Server.
The names for the processes must be unique within the complete Process Control network.
Command
The command string that starts the process as it would be entered on the command line. Use the full path for the command. For example, to configure a Cisco Info Server named NCOMS, enter:
`$OMNIHOME/bin/nco_objserv -name NCOMS -pa SFOSYS1_PA' run as 0
or:
`$OMNIHOME/bin/nco_objserv -name NCOMS -pa SFOSYS1_PA' run as `root'
The run as option instructs the host machine to run the Cisco Info Server as the specified user. Enter either the user ID (typically 0) or the user name in quotes (typically root). When a username is entered, the process agent looks up the user ID to use.
If the Process Control agent is not running as root, this option is ignored, and the process is run as the user who is running the Process Control agent.
For information about the Cisco Info Server command line options, see Specifying Cisco Info Server Command Line Options.
Host
The name of the host on which the process should be executed. Process Control automatically resolves the name of the Process Control agent when required.
Managed
Can have the value True (the process is restarted automatically if it exits) or False (the process is not restarted automatically if it exits).
RestartMsg
Contains the message to be sent to syslog if the process is restarted. For example, The Cisco Info Server has been restarted.
AlertMsg
Contains the message to be sent to syslog if the process exits. For example, The Cisco Info Server has gone down.
RetryCount
Specifies the number of restart attempts to be made if the process exits within the time specified by the process agent daemon -retrytime command line option. If set to 0, there is no limit to the number of restart attempts. The default is 0.
ProcessType
Can have the value PaPA_AWARE for PA aware processes and PaNOT_PA_AWARE for processes not PA aware. See Processes for additional information.
Expansion Keywords
You can include expansion keywords in the RestartMsg and AlertMsg entries in the configuration file. Expansion keywords act as variables and contain information about the process that has restarted. The expansion keywords are shown in Table 7-2.
Alert and Restart Syslog Messages
When an alert or restart message is generated by nco_pad, it is passed to the syslog system. Cisco Info Center has a Syslog Cisco Info Mediator that can monitor these messages and convert them into Cisco Info Server alerts. For more information about the Syslog Cisco Info Mediator, see the documentation available for each Cisco Info Mediator on the Cisco Systems Support Site.
The alert and restore messages are sent to syslog as warnings. The message is formatted as:
HOSTNAME : <ALERT_OR_RESTART_MSG> : <MSG>
where HOSTNAME is the name of the host which has reported the problem, <ALERT_OR_RESTART_MSG> describes the type of message. <MSG> is the text defined in the configuration file for that process or host.
Defining Services
You can define services to group together the functional elements of the system. A group of processes run together in a specified way provide a service. The processes must already be defined in the list of processes.
An example of a service definition in the configuration file is shown below.
nco_service `Omnibus'
{
ServiceType = Master
ServiceStart = Non-Auto
process `Info Server' NONE
process `Proxy' `Info Server'
process `Info Mediator' `Proxy'
process `Info Mediator-1' `Info Server'
process `Sleep' 5
}Service Definition Description
Table 7-3 contains a description of the service definition information contained in the configuration file.
Specifying Process Dependencies
The process attribute allows you to define the process that should be run as part of the service. You can add dependencies on each of the processes in the service. The format of the process attribute is as follows:
process `<processname>' <dependency>
where <processname> is the name of the process defined in the list of processes and <dependency> can be a numeric value, a string value, or NONE.
The dependency type numeric allows you to specify a time dependency, in seconds, for starting the dependent process. For example, if you enter 5, the process starts five seconds after the service has started.
The dependency type string allows you to specify another PA aware process within the same service. See Table 7-1 for more information about the process types.
In the example Omnibus service, the Cisco Info Server process starts first because it has no dependencies. Five seconds after the Cisco Info Server starts, the Sleep process starts. Once the Cisco Info Server is running successfully, Proxy and Cisco Info Mediator-1 start. When the proxy server is running, the Cisco Info Mediator process starts.
The dependency type NONE specifies no dependency.
Defining Secure Hosts
You can specify only certain hosts can connect to process agents by adding a security definition to the configuration file between the service and routing definitions, described in the next section.
If you do not create a security definition, any process can connect from any host.
You can create a security definition with no hosts specified, as follows:
nco_security
{
}When no hosts are specified, only processes running on the current host or any host listed in the routing definition can connect.
Processes running on hosts not listed in the routing definition can only connect if their host is listed in the security definition.
The process agent compares the IP address of the incoming connection with the IP address of each entry in the security and routing definitions and the local host. Only the main address of the host running the process agent daemon is automatically added to the security definition. You must add the loopback address (127.0.0.1) and secondary interfaces, if required.
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You can specify the following types of entries in the security definition:
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The following security definition allows connections from processes on hosts alpha, 192.9.200.34, and any host on the subnet 193.42.52.0.
nco_security
{
host 'alpha'
host '192.9.200.34'
host '193.42.52.*'
}Defining Routing Hosts, Usernames, and Passwords
To specify the hosts the process agents should contact to reach each other, you must define the process agent host names.
Each host field defines the name of the host (for example, sfosys1) and the name of the process agent to be used in the Process Control system (for example, SFOSYS1_PA).
When using Process Control in secure mode, the routing entry must also have a username and password.
Routing Definition Example
An example of a routing definition in the configuration file is shown next:
nco_routing
{
host 'sfosys1' 'SFOSYS1_PA' 'username' 'password'
host 'sfosys2' 'SFOSYS2_PA' 'username' 'password'
}If the process agent is using UNIX authentication (the default), the username must be an operating system user that is a member of the ncoadmin group, as described in Creating User Groups. A process agent daemon running in secure mode must be run by the root user.
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Password Encryption Example
You can use the nco_pa_crypt utility to encrypt plain text login passwords stored in the configuration file. Passwords encrypted using nco_pa_crypt are decrypted by the remote Process Control agent.
To encrypt a plain text password:
Step 1
$OMNIHOME/bin/nco_pa_crypt <password>
where <password> is the unencrypted form of the password. The nco_pa_crypt utility displays an encrypted version of the password.
Step 2
If the username is specified without a password, the system prompts for a password. If the password is specified without a username, the name of the user entering the command is used.
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You can also specify the username and password with the -username and -password command line options. This overrides any entries in the properties file.
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Example Process Agent Configuration File
The following example shows the settings for a simple process agent configuration file:
#NCO_PA3
#
# Process Agent Daemon Configuration File 1.1
#
#
# List of processes
#
nco_process `Info Server'
{
Command `$OMNIHOME/bin/nco_objserv -name NCOMS -pa SFOSYS1_PA' run as 0
Host = `sfosys1'
Managed = True
RestartMsg = `The Info Server has been restarted'
AlertMsg = `The Info Server has gone down'
RetryCount = 0
ProcessType = PaPA_AWARE
}
nco_process `Proxy'
{
Command `$OMNIHOME/bin/nco_proxyserv -name SCNCOMS -server NCOMS
-debug' run as 0
Host=`sfosys1'
Managed = True
RestartMsg = ` '
AlertMsg = ` '
RetryCount = 0
ProcessType = PaPA_AWARE
}
nco_process `Info Mediator'
{
Command `$OMNIHOME/probes/nco_p_simnet -server SCNCOMS' run as 0
Host = `sfosys1'
Managed = True
RestartMsg = ` `
AlertMsg = ` `
RetryCount = 0
ProcessType = PaNOT_PA_AWARE
}
nco_process `Info Mediator-1'
{
Command `$OMNIHOME/probes/nco_p_simnet -server NCOMS' run as 0
Host = `sfosys1'
Managed = True
RestartMsg = ` `
AlertMsg = ` `
RetryCount = 0
ProcessType = PaNOT_PA_AWARE
}
nco_process `Sleep'
{
Command `/usr/bin/sleep 500' run as 60003
Host = `sfosys1'
Managed = True
RestartMsg = `STARTED'
AlertMsg = `STOPPED'
RetryCount = 0
ProcessType = PaNOT_PA_AWARE
}
nco_process `Sleep-1'
{
Command `/usr/bin/sleep 500' run as 305
Host = `sfosys2'
Managed = True
RestartMsg = ` `
AlertMsg = ` `
RetryCount = 0
ProcessType = PaNOT_PA_AWARE
}
nco_process `Sleep-2'
{
Command `/usr/bin/sleep 500' run as 305
Host = `sfosys2'
Managed = True
RestartMsg = ` `
AlertMsg = ` `
RetryCount = 0
ProcessType = PaNOT_PA_AWARE
}
nco_process `Sleep-3'
{
Command `/usr/bin/sleep 500' run as 305
Host = `sfosys4'
Managed = True
RestartMsg = ` `
AlertMsg = ` `
RetryCount = 0
ProcessType = PaNOT_PA_AWARE
}
# List of Services
nco_service `Omnibus'
{
ServiceType = Master
ServiceStart = Non-Auto
process `Info Server' NONE
process `Proxy' `Info Server'
process `Info Mediator' `Proxy'
process `Info Mediator-1' `Info Server'
process `Sleep' 5
}
nco_service `Core'
{
ServiceType = Master
ServiceStart = Auto
process `Master Object Server' NONE
}
nco_security
{
}
# ROUTING TABLE
#
nco_routing
{
host `sfosys1' `SFOSYS1_PA' `ssmith' `sspass'
host `sfosys2' `SFOSYS2_PA' `ssmith' `sspass'
}Process Control Agent Daemon Command Line Options
This section describes the command line options for the Process Control agent daemon, nco_pad. Table 7-4 describes the Process Control agent command line options.
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Process Control Management
The Process Control system provides various utilities to manage and change the Cisco Info Center configuration. This section describes the following management utilities:
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Displaying Service Status - nco_pa_status
The nco_pa_status utility retrieves the status of services in the configuration. For each service, nco_pa_status returns a list of defined processes, the status of each process, and the UNIX process identifier. To display the service status, enter the command:
$OMNIHOME/bin/nco_pa_status -server <string>
In this command, <string> is the process agent name. The following is example output:
--------------------------------------------------------------------------
Service Name Process Name Hostname User Status PID
--------------------------------------------------------------------------
Master Service Info Server SFOSYS1 root RUNNING 16751
Proxy SFOSYS1 root RUNNING 16752
Sleep SFOSYS1 root RUNNING 16753
Info Mediator SFOSYS1 root RUNNING 16754
--------------------------------------------------------------------------Table 7-5 describes each of the status levels.
If a process agent is instructed to run a process by a process agent running on a separate machine, the remote process agent does not retain a record of the process. If the remote process agent stops, the process will continue to run. When the remote process agent restarts, it has no record of the process, and therefore the process status for this orphan process is listed as DEAD.
You can manually restart the process using the nco_pa_start utility. Table 7-6 describes the Process Control service nco_pa_status command line options.
Command Line Options
Starting a Service or Process - nco_pa_start
The nco_pa_start utility starts a service or process at any location in the configuration. You can only specify a single service or process. If the service or process has already been started, the command is ignored.
Command Line Options
Table 7-7 describes the Process Control service nco_pa_start command line options.
Stopping a Service or Process - nco_pa_stop
The nco_pa_stop utility stops a service or process at any location in the configuration. You can only specify a single service or process. If the service or process has already been stopped, the command is ignored.
Command Line Options
Table 7-8 describes the Process Control nco_pa_stop command line options.
Shutting Down a Process Control Agent - nco_pa_shutdown
The nco_pa_shutdown utility shuts down a complete Process Control agent and optionally stops associated services and processes.
Command Line Options
Table 7-9 describes the Process Control nco_pa_shutdown command line options.
Adding a New Service or Process to a Running PAD - nco_pa_addentry
The nco_pa_addentry utility enables you to add a new service or process to a running Process Control agent.
Note
Command Line Options
Table 7-10 describes the Process Control nco_pa_addentry command line options.
