HP OpenView System Administration Handbook [Electronic resources] : Network Node Manager, Customer Views, Service Information Portal, HP OpenView Operations نسخه متنی

14.1 THE OVO AGENTS

There are two types of OVO agents, DCE/NCS-based agents and HTTPS-based agents. DCE/NCS-based agents are the traditional agent type and use

remote procedure call (RPC) services to communicate with the server. HTTPS- based agents, used for highly secure communications, use standard Web security technologies (such as HTTP, SOAP, Proxies, SSL, and so on). Refer to Chapter 20, "Security," for more security information. Both types of agents are referred to in this chapter. The two types of agents are used similarly to manage the nodes. The node communications type is determined when you add the node to the OVO configuration. Select

ActionsNodeAdd to create a new node. The default machine type for the new node is HP PA-RISC (HTTPS), as shown in Figure 14-1. The default communication type is HTTPS, as shown in Figure 14-2.

14.1.1 List of Tasks Performed by the Agents

There are many tasks performed by the agent, and the tasks are not limited to the following list:

• Intercept messages from their respective source (logfile, SNMP traps, command line, or API)

• Filter the messages according to the templates and conditions activated on the managed node

• Log messages to a local file that could be used, for example, for debugging

• Buffer messages in the event the agent cannot communicate with the management server

• Execute local automatic actions

• Execute scheduled actions

• Execute operator initiated actions and respond to desktop application requests

• Forward messages to the management server

• Monitor thresholds

• Monitor the health and status of the agent itself

• Pass messages to external programs

• Perform message correlation

14.1.2 The Agent Processes

The agent processes provide the functionality for fault, event, service and performance management. The agent processes are distinguished into two categories, core and subagent. The core processes are primarily responsible for controlling agent startup and shutdown, monitoring the status of the other agents, communication functions, distribution, and configuration changes.

The subagents extend the functionality of the agent platform to perform tasks, such as reading a logfile, monitoring a threshold, and intercepting a message or an SNMP trap. During operation, the agent processes send or accept information and instructions from other local OVO processes or from the management server. One parent process is responsible for managing the other agents. It starts, stops, and provides status on all of the other agents as required. In order for a subagent to run the policy, templates for the subagent must be installed. Policy templates are referred to as policies on HTTPS-based nodes and are called templates on RPC-based nodes. For example, in order for the message interceptor to run, install the message policy along with the

opcmsg command. In order for the logfile encapsulator to run, install the logfile components (at least one logfile policy), and so on. Following are descriptions of the HTTPS agent processes:

• Control Agent (ovcd)
  Parent process, starts/stops/statuses subagents, communicates with the local communication broker.

• Message Agent (opcmsga )
  Sends messages to message receiver on OVO server, sends action responses to the server, interface for programs that access the internal

  message stream interface (MSI), forwards data to other OVO servers, and sends agent alive packet to server. MSI is covered in Section 14.5.3.

• HTTPS Communication Broker (ovbbccb)
  Listens on port 383 for HTTP connection requests; returns port number of registered programs.

• Configure/Distribute (ovconfd)
  Distributes policies to the final location on the local file system.

• Action Agent (opcacta)
  Starts/stops automatic and operator actions; handles command broadcast and other desktop application requests.

• Logfile Encapsulator (opcle)
  Reads logfile(s), checks the logfile nodes and creates time, and triggers a file to be executed. The file to be executed is used in a case when the actual logfile may be a binary file. The content of the binary file must be converted into ASCII format and stored in a readable file in order for the logfile encapsulator to process the data. The file that is executed is the program that converts the binary file into ASCII format. For example, in order to convert the binary file wtmp, you need to execute the command

  last . The output from the execution of the command can be redirected to a file (such as /usr/bin/last agent process>/tmp/last.out). This process is referred to as the binary conversion process. Then the file to be read becomes /tmp/last.out.

• Monitor Agent (opcmona)
  Executes monitor scripts, checks monitor script returned values against threshold, creates message and sends to message agent, handles scheduled actions, and connects to the embedded performance component for performance monitor requests.

• Message Interceptor (opcmsgi)
  Intercepts messages created with the

  opcmsg command or the

  application program interface (API), evaluates message for match condition, and sends matched message to the message agent.

• Trap Interceptor (opctrapi)
  Converts SNMP traps to OVO messages, sends messages to the message agent, can register with NNM to obtain incoming traps or listen for traps on port 162.

• Event Correlation Agent (opceca)
  Correlates events on the node; requires an ECS policy.

• ECS Annotate Server (opcecaas)
  Starts external programs; requires ECS engine.

• Security Certificate Client (ovcs)
  Used during installation to allow or deny certificate requests.

• Performance Agent (coda)
  Embedded performance component; collects performance metrics data.

The RPC-based agent processes, when installed with the default templates, are listed here:

• Control agent (opcctla)

• Message agent (opcmsga)

• BBC Location Broker (llbserver)

• Action agent (opcacta)

• Monitor agent (opcmona)

• Message Interceptor (opcmsgi)

• Trap Interceptor (opctrapi)

• Performance agent (coda)