关于使用Nagios远程提取Informix信息及监控Oracle、Informix数据库的技术咨询

Hey there! I’ve got you covered on your Nagios monitoring questions for your school project—let’s dive right in.

Absolutely! Nagios has solid support for Oracle monitoring, mostly through community-maintained plugins like check_oracle_health. Here’s the gist:

• You’ll need the Oracle Instant Client installed on either the Nagios server or the remote CentOS VM (depending on whether you run checks locally or via NRPE).
• The plugin can monitor key metrics like database connectivity, tablespace usage, active sessions, and listener status.
• Just configure the plugin with your Oracle credentials, set up a service definition in Nagios, and you’re good to go.

Yes, it can—this is totally doable, even if documentation is a bit harder to find than for Oracle. Here are your best solutions:

1. Use the Community-Maintained check_informix Plugin #

There’s a custom plugin called check_informix built specifically for this. Here’s how to set it up:

• First, install the Informix Client SDK on your remote CentOS VM. Make sure to set environment variables like INFORMIXDIR and INFORMIXSERVER correctly so the plugin can talk to the database.
• Grab the check_informix script (available in Nagios community repositories) and place it in your Nagios plugins directory (usually /usr/local/nagios/libexec/).
• Give it execute permissions: chmod +x check_informix.
• Configure NRPE (Nagios Remote Plugin Executor) on the remote VM to run this plugin. Add a line like this to nrpe.cfg:

  command[check_informix_status]=/usr/local/nagios/libexec/check_informix -d YOUR_DBNAME -u DB_USER -p DB_PASSWORD
  

• Restart the NRPE service: systemctl restart nrpe.

2. Write Your Own Custom Script #

If you can’t find the pre-built plugin, writing a simple shell or Python script works too. Use Informix’s built-in command-line tools like dbaccess or onstat to pull metrics:

• For example, a shell script to check if the database is responsive might look like this:

  #!/bin/bash
  export INFORMIXDIR=/opt/informix
  export INFORMIXSERVER=your_informix_server
  
  # Test database connectivity
  dbaccess YOUR_DBNAME - <<EOF
  SELECT COUNT(*) FROM systables WHERE tabname='systables';
  EOF
  
  # Parse the output to return Nagios-compatible status codes (0=OK, 1=WARNING, 2=CRITICAL)
  if [ $? -eq 0 ]; then
      echo "OK: Informix database is responsive"
      exit 0
  else
      echo "CRITICAL: Could not connect to Informix database"
      exit 2
  fi
  

• Save this script, make it executable, and add it to your NRPE config just like the pre-built plugin.

3. Key Informix Metrics to Monitor #

Don’t forget to track these critical stats:

• Database instance status (use onstat - to check if the server is up)
• Dbspace usage (to avoid running out of storage for your database)
• Active sessions and lock contention (with onstat -u and onstat -l)
• Logical log usage (to prevent log full errors)

The standard way to pull remote Informix data into Nagios is using NRPE—here’s the step-by-step:

1. Install NRPE and Nagios plugins on your remote CentOS VM (most distros have packages for this, like nagios-nrpe-server and nagios-plugins).
2. Edit nrpe.cfg to allow your Nagios server’s IP address to connect (look for the allowed_hosts directive).
3. Deploy your Informix monitoring plugin/script to the VM’s plugin directory and configure the NRPE command as shown earlier.
4. On your Nagios server, define a service that uses the check_nrpe plugin to call the remote command. Example service definition:

   define service {
       host_name               remote-centos-vm
       service_description     Informix Database Status
       check_command           check_nrpe!check_informix_status
       max_check_attempts      3
       check_interval          5
       retry_interval          1
       check_period            24x7
       notification_interval   60
       notification_period     24x7
   }
   

5. Test it out! Run this command on your Nagios server to verify:

   /usr/local/nagios/libexec/check_nrpe -H REMOTE_VM_IP -c check_informix_status
   

   You should get a status message telling you if the Informix database is OK or has issues.

内容的提问来源于stack exchange，提问作者kadar