# grep syslog-ng /var/log/messages | egrep -v '(Syslog connection|EOF on control channel|Log statistic|sudo:)'

Apr  1 16:45:05 hostXXX syslog-ng: Last message 'Invalid byte sequenc' repeated 14 times, suppressed by syslog-ng on hostXXX.gisa-halle.de
Apr  1 16:45:05 hostXXX syslog-ng[31267]: Configuration reload request received, reloading configuration;

### above is the time, where logrotate was running an HUPs syslog-ng

Apr  1 16:45:08 hostXXX syslog-ng[31267]: Invalid byte sequence or other error while converting input, skipping character; encoding='\xa0\xb6a', char='0xd7'
Apr  1 16:45:13 hostXXX syslog-ng: Last message 'Invalid byte sequenc' repeated 3 times, suppressed by syslog-ng on hostXXX.gisa-halle.de
Apr  1 16:45:13 hostXXX syslog-ng[31267]: Invalid byte sequence or other error while converting input, skipping character; encoding='E[FFEC1B90 verbose \'Default\' opID=HB-host-156342@65223-27321819-58] [VpxaStatsMetadata] Mapping VpxdCounter 439 to hostd counter 655379', char='0xd7'

### above are lines which belongs to an other thread: "strange error message: Invalid byte sequence or other error while converting input". perhaps they are somehow related.

Apr  1 16:45:20 hostXXX syslog-ng[8204]: syslog-ng starting up; version='3.4.1'

### the line above belongs to the reload? it seems delayed....

Apr  1 16:46:20 hostXXX syslog-ng[8204]: Invalid byte sequence or other error while converting input, skipping character; encoding='UTF-8', char='0xd7'
Apr  1 16:46:44 hostXXX syslog-ng: Last message 'Invalid byte sequenc' repeated 55 times, suppressed by syslog-ng on hostXXX.domain.tld

### many more of this lines above; always encoding='UTF-8', char='0xd7'

Apr  3 10:40:47 hostXXX syslog-ng[8204]: Configuration reload request received, reloading configuration;
Apr  3 10:47:01 hostXXX syslog-ng[41739]: syslog-ng starting up; version='3.4.1'

### my 1st test to reproduce the problem. 7 minutes later the 'starting up' message?

Apr  3 10:52:26 hostXXX syslog-ng[41739]: Configuration reload request received, reloading configuration;
Apr  3 10:53:28 hostXXX syslog-ng[41739]: Configuration reload request received, reloading configuration;

### two fast HUPs -> garbage in mongodb

Apr  3 10:53:52 hostXXX syslog-ng[41739]: syslog-ng shutting down; version='3.4.1'
Apr  3 10:53:53 hostXXX syslog-ng[42083]: syslog-ng starting up; version='3.4.1'

### restart to have no garbage anymore