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deleted 49 characters in body; edited title

edited May 20 at 17:42

Journalctl logs and how the systemctl mechanism verifies and performs DNS verification& name resolution

We are debugging the logging of some services, such as the moving_data_to_hdfs.service, on our RHEL 7.6 machines.

We ran the following command:

journalctl -u moving_data_to_hdfs.service >/log.txt

From the journalctl logs, we observed many exceptions like:

Failed to establish a new connection: [Errno -3] Temporary failure in name resolution

However, when we check the resolution for all hostnames and IP addresses, we do not find any issues.

We also prepared a bash script that checks, in a loop, the resolution of all IPs and hostnames in our cluster, and the results are fine.

Example:

Host <hostname> Host <xxx.xxx.xxx.xxx>

So, referring back to the journalctl logs, which are complaining about DNS resolution, we want to understand:

How does systemctl test DNS? Or what approach does systemctl use to test the resolution of hostnames or IP addresses?

We are debugging the logging of some services, such as the moving_data_to_hdfs.service, on our RHEL 7.6 machines.

We ran the following command:

journalctl -u moving_data_to_hdfs.service >/log.txt

From the journalctl logs, we observed many exceptions like:

Failed to establish a new connection: [Errno -3] Temporary failure in name resolution

However, when we check the resolution for all hostnames and IP addresses, we do not find any issues.

We also prepared a bash script that checks, in a loop, the resolution of all IPs and hostnames in our cluster, and the results are fine.

Example:

Host <hostname> Host <xxx.xxx.xxx.xxx>

So, referring back to the journalctl logs, which are complaining about DNS resolution, we want to understand:

How does systemctl test DNS? Or what approach does systemctl use to test the resolution of hostnames or IP addresses?

We are debugging the logging of some services, such as the moving_data_to_hdfs.service, on our RHEL 7.6 machines.

We ran the following command:

journalctl -u moving_data_to_hdfs.service >/log.txt

From the journalctl logs, we observed many exceptions like:

Temporary failure in name resolution

However, when we check the resolution for all hostnames and IP addresses, we do not find any issues.

We also prepared a bash script that checks, in a loop, the resolution of all IPs and hostnames in our cluster, and the results are fine.

Example:

Host <hostname> Host <xxx.xxx.xxx.xxx>

So, referring back to the journalctl logs, which are complaining about DNS resolution, we want to understand:

How does systemctl test DNS? Or what approach does systemctl use to test the resolution of hostnames or IP addresses?

asked May 20 at 12:38

We are debugging the logging of some services, such as the moving_data_to_hdfs.service, on our RHEL 7.6 machines.

We ran the following command:

journalctl -u moving_data_to_hdfs.service >/log.txt

From the journalctl logs, we observed many exceptions like:

Failed to establish a new connection: [Errno -3] Temporary failure in name resolution

However, when we check the resolution for all hostnames and IP addresses, we do not find any issues.

We also prepared a bash script that checks, in a loop, the resolution of all IPs and hostnames in our cluster, and the results are fine.

Example:

Host <hostname> Host <xxx.xxx.xxx.xxx>

So, referring back to the journalctl logs, which are complaining about DNS resolution, we want to understand:

How does systemctl test DNS? Or what approach does systemctl use to test the resolution of hostnames or IP addresses?