pgsnmpd

pgsnmpd is an SNMP agent that can return hierarchical information about the current state of Advanced Server on a Linux system. pgsnmpd is distributed and installed using the edb-asxx-pgsnmpd RPM package where xx is the Advanced Server version number. The pgsnmpd agent can operate as a stand-alone SNMP agent, as a pass-through sub-agent, or as an AgentX sub-agent.

After installing Advanced Server, you will need to update the LD_LIBRARY_PATH variable. Use the command:

$ export LD_LIBRARY_PATH=/usr/edb/as13/lib:$LD_LIBRARY_PATH

This command does not persistently alter the value of LD_LIBRARY_PATH. Consult the documentation for your distribution of Linux for information about persistently setting the value of LD_LIBRARY_PATH.

The examples that follow demonstrate the simplest usage of pgsnmpd, implementing read only access. pgsnmpd is based on the net-snmp library; for more information about net-snmp, visit:

Configuring pgsnmpd

The pgsnmpd configuration file is named snmpd.conf. For information about the directives that you can specify in the configuration file, please review the snmpd.conf man page (man snmpd.conf).

You can create the configuration file by hand, or you can use the snmpconf perl script to create the configuration file. The perl script is distributed with net-snmp package.

net-snmp is an open-source package available from:

To use the snmpconf configuration file wizard, download and install net-snmp. When the installation completes, open a command line and enter:

snmpconf

When the configuration file wizard opens, it may prompt you to read in an existing configuration file. Enter none to generate a new configuration file (not based on a previously existing configuration file).

snmpconf is a menu-driven wizard. Select menu item 1: snmpd.conf to start the configuration wizard. As you select each top-level menu option displayed by snmpconf, the wizard walks through a series of questions, prompting you for information required to build the configuration file. When you have provided information in each of the category relevant to your system, enter Finished to generate a configuration file named snmpd.conf. Copy the file to:

/usr/edb/as13/share/

Setting the Listener Address

By default, pgsnmpd listens on port 161. If the listener port is already being used by another service, you may receive the following error:

Error opening specified endpoint "udp:161".

You can specify an alternate listener port by adding the following line to your snmpd.conf file:

agentaddress $host_address:2000

The example instructs pgsnmpd to listen on UDP port 2000, where $host_address is the IP address of the server (e.g., 127.0.0.1).

Before invoking pgsnmpd, you must create the pgsnmpd schema and set the search path to create tables in the pgsnmpd schema using the following commands:

CREATE SCHEMA pgsnmpd;
SET search_path = pgsnmpd;
\i pgsnmpd.sql

Invoking pgsnmpd

Ensure that an instance of Advanced Server is up and running (pgsnmpd will connect to this server). Open a command line and assume superuser privileges, before invoking pgsnmpd with a command that takes the following form:

POSTGRES_INSTALL_HOME/bin/pgsnmpd -b
  -c POSTGRES_INSTALL_HOME/share/snmpd.conf
  -C "user=enterprisedb dbname=edb password=safe_password
      port=5444"

Where POSTGRES_INSTALL_HOME specifies the Advanced Server installation directory.

Include the -b option to specify that pgsnmpd should run in the background.

Include the -c option, specifying the path and name of the pgsnmpd configuration file.

Include connection information for your installation of Advanced Server (in the form of a libpq connection string) after the -C option.

Viewing pgsnmpd Help

Include the --help option when invoking the pgsnmpd utility to view other pgsnmpd command line options:

pgsnmpd --help
  Version PGSQL-SNMP-Ver1.0
  usage: pgsnmpd [-s] [-b] [-c FILE ] [-x address ] [-g] [-C "Connect
  String"]
     -s : run as AgentX sub-agent of an existing snmpd process
     -b : run in the background
     -c : configuration file name
     -g : use syslog
     -C : libpq connection string
     -x : address:port of a network interface
     -V : display version strings

Requesting Information from pgsnmpd

You can use net-snmp commands to query the pgsnmpd service. For example:

snmpgetnext -v 2c -c public localhost .1.3.6.1.4.1.5432.1.4.2.1.1.0

In the above example:

-v 2c option instructs the snmpgetnext client to send the request in SNMP version 2c format.

-c public specifies the community name.

localhost indicates the host machine running the pgsnmpd server.

.1.3.6.1.4.1.5432.1.4.2.1.1.0 is the identity of the requested object. To see a list of all databases, increment the last digit by one (e.g. .1.1, .1.2, .1.3 etc.).

The encodings required to query any given object are defined in the MIB (Management Information Base). An SNMP client can monitor a variety of servers; the server type determines the information exposed by a given server. Each SNMP server describes the exposed data in the form of a MIB (Management information base). By default, pgsnmpd searches for MIB’s in the following locations:

/usr/share/snmp/mibs

$HOME/.snmp/mibs