Fluentd fails to send logs to external syslog server for record with severity=unknown

Issue

• After configuring fluentd daemonset to send logs to external syslog server as per the official documentation , the external syslog server does not receive logs if application logs have severity/loglevel=unknown and environment variableREMOTE_SYSLOG_USE_RECORD is set to true.

• Fluentd pod logs are flooded with below error messages:

2020-07-06 13:05:34 ... temporarily failed to flush the buffer. next_retry=2020-07-06 13:05:35 ... error_class="ArgumentError" error='unknown' ... plugin_id=remote-syslog-input
2020-07-06 13:05:35 ... temporarily failed to flush the buffer. next_retry=2020-07-06 13:05:36 ... error_class="ArgumentError" error='unknown' ... plugin_id=remote-syslog-input