Debugging and Troubleshooting: _sqlsrv2 processes dying/terminating unexpectedly.
How to debug/troubleshoot _sqlsrv2 processes dying/terminating unexpectedly.
_sqlsrv2 process terminating unexpectedly.
_sqlsrv2 process dying unexpectedly.
_sqlsrv2 process disappearing unexpectedly.
protrace incomplete after crash of _sqlsrv2 with errors 2526 and 2256 
protrace incomplete after crash of _sqlsrv2 with errors 5029 and 3719
Error 1153 in the db log for SQL server processes. 
 

To further troubleshoot _sqlsrv2 processes dying/terminating unexpectedly:

1. Parse the db log for errors and associate the server number with the PID for the _sqlsrv2 process. 
   • For example error 1153 reports that server process with PID 12345678 died, the PID can be associated with server number 134 which is a SQL server:

P-12345678   T-x   I SRV   134: (7129)  Usr x set name to x. 
P-12345678  T-x   I SQLSRV2 134: (-----) Login by user x. Using TCP/IP IPV4 address x.x.x.x
P-10101010    T-x     I BROKER  0: (1153)  BROKER detects death of server 12345678.

2. Search the system for Protrace files with the PIDs identified above and time stamps close to the crash, (e.g. protrace.<PID>) if protraces are incomplete, please visit this article:  protrace incomplete after crash of _sqlsrv2
   • Protrace files in more recent versions show more and more useful information that may help understand the cause
   • If the protrace file contains the SQL statement that caused the crash, can you run it at will and cause the crash?
   • Can you find any historical cases by searching (google, Progress Knowledgebase) for the items listed in the call stack from the protrace file?
   • If on Windows, were the proper PDB files installed?  What is the purpose of .PDB files?
3. Use SQL statement logging to try to narrow down the SQL queries that were being executed during the crash, SQL-92: How to turn SQL statement logging on and off?.
   • You can use logging to look for trends in behavior.  For instance, is it always a specific sequence of SQL Statements/Calls that caused the problem?
   • Looking at the last query in the log, can it crash the SQL server process if it is executed by itself? 
4. In addition to SQL statement logging, Enable 1:1 client server ratio for the SQL broker, -Ma 1. Check with System Administrator and/or DBA to see if it is possible as more server ports can be needed and the -Mn or -Mpb might have to be increased. This can help to isolate the problem.
5. Are there any system errors around the time the crash happened? 
6. Enable OS Audit in your system. Article  How to enable OS Auditing on Linux?
7. Check if OOM killer is killing the processes. Article What is the OOM Killer (Out of Memory Killer)?. 
8. Try updating statistics.  Does the problem go away outright?  SQL-92: 'Update Statistics' Explained  / How to undo UPDATE STATISTICS
9. Are there any pen tests or port scanners running at the time of the crashes? 

Please engage Progress Technical Support for further assistance with _sqlsrv2 processes dying/terminating unexpectedly, providing all artifacts from your research thus far.