Sometimes some sdmgr plugins (RM, NM, TM, IM and PM) are stopped.
In TRC_USD_*MAN*.log (like TRC_USD_INSTMAN*.log) following errors could appear before stop :
evalSQLInfo sqlstate: 08S01 native error: 121 0x79
evalSQLInfo description: Communication link failure source: Microsoft SQL Server Native Client 11.0
evalSQLInfo sqlstate: 08S01 native error: 121 0x79
evalSQLInfo description: TCP Provider: The semaphore timeout period has expired.
source: Microsoft SQL Server Native Client 11.0
evalSQLInfo class: 16 state: 1 server:
Error Message: ADO Version 6.3 - COM Error: ErrorCode:-2147467259,WordErrorCode:0, Unspecified error, TCP Provider: The semaphore timeout period has expired.
evalSQLInfo sqlstate: 08S01 native error: 0 0x0
Error Message: ADO Version 6.3 - COM Error: ErrorCode:-2147467259,WordErrorCode:0, Unspecified error, Communication link failure, Microsoft SQL Server Native Client 11.0, (null)
Client Automation - All version