In general, it is best to locate the Coordinators as close as possible to the SQL instance where Change Auditor database resides. This will help ensure reliable bandwidth and low latency when dealing with Coordinator/SQL transactions.
This is of course is rule which has exceptions such as multi-forest deployments, DMZ requirements, etc. where based on product architecture Coordinators may need to be deployed remotely to SQL.
If running Coordinator in remote scenario with high latency to SQL consider the following Coordinator SQL timeout registry keys if frequent timeout warnings are encountered in the Coordinator service log file:
SQL Command TimeoutLocation: RegistryPath: HKEY_LOCAL_MACHINE\SOFTWARE\Quest\ChangeAuditorValue Name: SQLTimeoutValue Type: DWORDValue: Default 30 seconds (decimal)Value: Maximum time in seconds for SQL command to execute. Impacts most client and Coordinator queries.Note: Start with 600 seconds (decimal) and increase to 1200 if the warnings continue after increasing to 600 and waiting about a dayBulk SQL Command TimeoutLocation: RegistryPath: HKEY_LOCAL_MACHINE\SOFTWARE\Quest\ChangeAuditorValue Name: BulkSQLTimeoutValue Type: DWORDValue: Default = 30 seconds (decimal)Value: Maximum time in seconds for bulk SQL command to execute. This includes bulk insertion of SQL events from agents. Note: Start with 600 seconds (decimal) and increase to 1200 if the warnings continue after increasing to 600 and waiting about a day