On my collectd server, the syslog file is filled very fast with many messages like these :
collectd-srv01.mydomain.com collectd[]: uc_update: Value too old: name = another_server.mydomain.com/some_metric; value time = 1674488856.852; last cache update = 1674488859.624;
collectd-srv01.mydomain.com collectd[]: Filter subsystem: Built-in target `write': Dispatching value to all write plugins failed with status -1.
collectd-srv01.mydomain.com collectd[]: Filter subsystem: Built-in target `write': Some write plugin is back to normal operation. `write' succeeded.