In a sharded cluster that has auditing enabled, the following error occurs every 30s when a distributed lock is pinged:
2015-03-26T08:00:32.332+1100 W SHARDING [LockPinger] distributed lock pinger 'genique:22025,genique:22026,genique:22027/genique:22023:1427317232:2093216429' detected an exception while pinging. :: caused by :: SyncClusterConnection::update prepare failed: genique:22025 (127.0.1.1):getLastError command failed: Audit metadata does not include both user and role information. genique:22026 (127.0.1.1):getLastError command failed: Audit metadata does not include both user and role information. genique:22027 (127.0.1.1):getLastError command failed: Audit metadata does not include both user and role information. 2015-03-26T08:01:02.385+1100 W SHARDING [LockPinger] distributed lock pinger 'genique:22025,genique:22026,genique:22027/genique:22023:1427317232:2093216429' detected an exception while pinging. :: caused by :: SyncClusterConnection::update prepare failed: genique:22025 (127.0.1.1):getLastError command failed: Audit metadata does not include both user and role information. genique:22026 (127.0.1.1):getLastError command failed: Audit metadata does not include both user and role information. genique:22027 (127.0.1.1):getLastError command failed: Audit metadata does not include both user and role information. 2015-03-26T08:01:32.386+1100 W SHARDING [LockPinger] distributed lock pinger 'genique:22025,genique:22026,genique:22027/genique:22023:1427317232:2093216429' detected an exception while pinging. :: caused by :: SyncClusterConnection::update prepare failed: genique:22025 (127.0.1.1):getLastError command failed: Audit metadata does not include both user and role information. genique:22026 (127.0.1.1):getLastError command failed: Audit metadata does not include both user and role information. genique:22027 (127.0.1.1):getLastError command failed: Audit metadata does not include both user and role information.
I've only seen this on shard primaries, but it might happen on mongoses too (haven't tried/checked).