High angle view of Beijing Guomao.
If your host is physically available and the operating system is up and running, but you cannot access your network to the Vertica cluster, then external connections might not be possible. Client software connections are failing, and users are not able to ssh to the host. From observing a hardware console connection, it looks like the host is still running.
Check if any of the following problems exist:
| Step | Task | Results |
|---|---|---|
| 1 | Get the initial information from the NETWORK_USAGE system table.
=> SELECT * FROM NETWORK_USAGE; |
Upon getting information about the NETWORK_USAGE system table, proceed to Step 2. |
| 2 | Are you having problems pinging the default route IP address or router address? | If yes, the router is down or misconfigured. Reconfigure and restart the router. Consult with local network administrator. If no, go to Step 3. |
| 3 | If the firewall enabled? | If yes, disable the firewall, check settings, and go to Step 4. If no, check the settings and go to Step 4. |
| 4 | Are firewall settings blocking ports needed by Vertica? Using default settings and blocking ports needed by Vertica can cause firewall problems. | If yes, run the following commands to disable the firewall:
$ service iptables save
$ service iptables stop
$ chkconfig iptables off
$ service ip6tables save
$ service ip6tables stop
$ chkconfig ip6tables off
If no, go to Step 5. |
| 5 | Check the network ports in use:
netstat -atupn
Vertica requires the following network ports:
|
If some of the ports are blocked, review list of ports required by Vertica and open ports on the firewall. If no problems, go to Step 6. |
| 6 | Has a DNS configuration error occurred? | If yes,
|
| 7 | Is there a physical cable problem? Is the wrong network interface or cable in the wrong port? | If yes, ask the local network administrator to check the physical host and network cables. If no, go to Step 8. |
| 8 | Is the default network gateway configured incorrectly? | If yes, configure the gateway route. Without a default route, network traffic remains local on a server.
Use the following command to display route information:$ netstat -r -n
If no, go to Step 9. |
| 9 | Do you have a bad IP address or a duplicate IP address? | If yes, check and modify the network IP address. Use ifconfig -a to verify the IP address and use ping to confirm the correct host using the IP address. If no, go to Step 10. |
| 10 | Is the network mask incorrect? | If yes, verify the network mask settings with your network administrator and update as needed.
Use the ifconfig –a command to review network settings and the network mask.Eth0 Link encap:Ethernet HWaddr D8:9D:67:6B:50:80
inet addr:10.10.10.4 Bcast:10.10.10.255 Mask:255.255.255.0
If no, go to Step 11. |
| 11 | Are you experiencing dropped packets or a slow network connection? | If yes, consult with your local network administrator regarding changes or settings.
To review network configuration settings or errors, use the command ifconfig -a and your specific network adapter.
Look for the following line in the output and a high number of errors and dropped packets:
RX packets:184412793438 errors:112992 dropped:0 overruns:99679 frame:13313
If no, go to Step 12. |
| 12 | Is the physical network cable crimped or crushed between the server and the switch? | If yes, check and replace the network cable. Symptoms appear with a high number of dropped packets.
To review settings, use the command: ifconfig -a and your specific network adapter.
Look for the following line in the output and a high number of errors and dropped packets.RX packets:184412793438 errors:112992 dropped:0 overruns:99679 frame:13313
If no, go to Step 13. |
| 13 | Is the switch firmware version is out of date, or are patches needed? | If yes, install the necessary patches. Consult your network administrator about firmware patches. If no, go to Step 14. |
| 14 | Is the switch’s Network Address Translation (NAT) table incorrect or recently changed? | If yes, consult your local network administrator regarding changes or settings. Verify and resolve network changes. |
| 15 | Are Linux network drivers or are patches needed? | If yes, check that the network drivers are up to date. Install patches if required. If not, run yum –update to perform any required updates and install patches. If no, consult with Vertica technical support. |
Learn More
Learn more about NETWORK_USAGE system table and NETWORK_INTERFACES system table in the Vertica Documentation. Also, see Configuring Network for Import and Export Data in the Vertica Knowledge Base.About the Author
Soniya Shah
Information Developer
Currently, a first year law student with a background in science and technology. Experienced technical writer, with specializations in software documentation, big data, blog development, and website development. I build user-centered content to communicate complex and technical information more easily.
I used to work for Vertica full time for about 3 years. I still work at Vertica part time while going to law school.
Update: Soniya is now doing her law internship, and no longer working at Vertica. Good luck, Soniya!
