#41 ASEMON process causing stack trace sometimes

[Hardeep]

Hi JPM
I hope you guys are going well.
Just wanted to understand the reason why asemon process sometimes triggers a stack trace on ASE server. And, how can we avoid this if any configuraiton we need to review on ASEMON xml or ASE side plesae suggest

As always many thanks for your great support.

00:0023:00000:01385:2023/03/01 11:04:28.45 kernel SQL causing error : set nocount on if exists (select * from master..monProcessStatement where KPID=266012207 and BatchID=152123 and ContextID=1 and LineNumber=0) begin ex
00:0023:00000:01385:2023/03/01 11:04:28.45 kernel Current statement number: 71 Current line number: 165
00:0023:00000:01385:2023/03/01 11:04:28.45 kernel ******
00:0023:00000:01385:2023/03/01 11:04:28.45 server SQL Text: set nocount on if exists (select * from master..monProcessStatement where KPID=266012207 and BatchID=152123 and ContextID=1 and LineNumber=0) begin exec sp_showplan 327,null, null ,null end set nocount off
00:0023:00000:01385:2023/03/01 11:04:28.45 server SQL Text: select @return_value = show_plan(@spid, @batch_id, @context_id, -1, @display_level)

00:0023:00000:01385:2023/03/01 11:04:28.45 kernel curdb = 2 tempdb = 19 pstat = 0x10000 p2stat = 0x40101000
00:0023:00000:01385:2023/03/01 11:04:28.45 kernel p3stat = 0x800 p4stat = 0x0 p5stat = 0xc008 p6stat = 0x10000001 p7stat = 0x10000
00:0023:00000:01385:2023/03/01 11:04:28.45 kernel lasterror = 0 preverror = 0 transtate = 1
00:0023:00000:01385:2023/03/01 11:04:28.45 kernel curcmd = 193 program = asemon_logger
00:0023:00000:01385:2023/03/01 11:04:28.45 kernel extended error information: hostname: usyddbp23200.macbank login: perfmon_dba
00:0023:00000:01385:2023/03/01 11:04:28.45 kernel pc: 0x000000000154dc90 pcstkwalk+0x482()
00:0023:00000:01385:2023/03/01 11:04:28.45 kernel pc: 0x000000000154d64f ucstkgentrace+0x20f()
00:0023:00000:01385:2023/03/01 11:04:28.45 kernel pc: 0x0000000001549dd2 ucbacktrace+0x54()
00:0023:00000:01385:2023/03/01 11:04:28.45 kernel pc: 0x00000000018198be terminate_process+0xb1e()
00:0023:00000:01385:2023/03/01 11:04:28.45 kernel pc: 0x000000000157b304 kisignal+0x868()
00:0023:00000:01385:2023/03/01 11:04:28.45 kernel pc: 0x000000000095190c le_showPLL+0x1()
00:0023:00000:01385:2023/03/01 11:04:28.45 kernel pc: 0x000000000110d9e2 showplan+0x29a()
00:0023:00000:01385:2023/03/01 11:04:28.45 kernel pc: 0x0000000001035a12 show_plan+0x808()
00:0023:00000:01385:2023/03/01 11:04:28.45 kernel pc: 0x0000000001892bf3 LeRun+0x9ba3()
00:0023:00000:01385:2023/03/01 11:04:28.45 kernel pc: 0x0000000001885b20 LeEvals::LeEvRun(LeRunMode, LeRunStack, short, LeDataRow, unsigned char, int)+0x70()
00:0023:00000:01385:2023/03/01 11:04:28.45 kernel pc: 0x00000000022ffbee LeScalarOp::_LeOpNext(ExeCtxt&)+0x4e()
00:0023:00000:01385:2023/03/01 11:04:28.45 kernel pc: 0x00000000022ea010 LeEmitNoSndOp::_LeOpNext(ExeCtxt&)+0x1c0()
00:0023:00000:01385:2023/03/01 11:04:28.45 kernel pc: 0x000000000185a7a0 LePlanNext+0x7e0()
00:0023:00000:01385:2023/03/01 11:04:28.45 kernel [Handler pc: 0x0x0000000001fbbf50 le_execerr installed by the following function:-]
00:0023:00000:01385:2023/03/01 11:04:28.45 kernel pc: 0x0000000001fbd9d0 exec_lava+0xad0()
00:0023:00000:01385:2023/03/01 11:04:28.45 kernel pc: 0x0000000002052636 s_execute+0x12b6()
00:0023:00000:01385:2023/03/01 11:04:28.45 kernel [Handler pc: 0x0x00000000020b9ab0 hdl_stack installed by the following function:-]
00:0023:00000:01385:2023/03/01 11:04:28.45 kernel [Handler pc: 0x0x000000000207da90 s_handle installed by the following function:-]
00:0023:00000:01385:2023/03/01 11:04:28.45 kernel pc: 0x00000000020822a3 sequencer+0xd13()
00:0023:00000:01385:2023/03/01 11:04:28.45 kernel pc: 0x0000000002067a26 execproc+0xcf6()
00:0023:00000:01385:2023/03/01 11:04:28.45 kernel pc: 0x0000000002055996 s_execute+0x4616()
00:0023:00000:01385:2023/03/01 11:04:28.45 kernel [Handler pc: 0x0x00000000020b9ab0 hdl_stack installed by the following function:-]
00:0023:00000:01385:2023/03/01 11:04:28.45 kernel [Handler pc: 0x0x000000000207da90 s_handle installed by the following function:-]
00:0023:00000:01385:2023/03/01 11:04:28.45 kernel pc: 0x00000000020822a3 sequencer+0xd13()
00:0023:00000:01385:2023/03/01 11:04:28.45 kernel pc: 0x0000000001838eba tdsrecv_language+0x1ea()
00:0023:00000:01385:2023/03/01 11:04:28.45 kernel [Handler pc: 0x0x00000000021d8330 ut_handle installed by the following function:-]
00:0023:00000:01385:2023/03/01 11:04:28.45 kernel pc: 0x000000000184fe79 conn_hdlr+0x12e9()
00:0023:00000:01385:2023/03/01 11:04:28.45 kernel end of stack trace, spid 1385, kpid 1923681371, suid 6
00:0024:00000:01591:2023/03/01 11:45:36.46 server INFO: Total Object Ids in temporary database generated: 500000000, LWPs generated: 495230820

Regards
Hardeep

[Jean-Paul Martin]

Hi Hardeep
Yes, I know this stacktrace triggered by sp_showplan.
SAP support told me in the past that this could occur when there are concurrent executions of "dbcc sqltext( ...) " requested by other users (some DBA tools can use this dbcc command)

There is a note on SAP support site :
2911437 - Signal 11 in showplan() - SAP ASE 16.0
which describes one case of stack trace triggered bu sp_sysmon (not sure if it is excatly your case)
This bug seems fixed in V16SP03PL09
If not, open an incident at SAP support
or disable the MonSQL collector in asemon (but you will no longer monitor SQL statements)
In general all case of this stack trace was not harmfull and I didn't disable MonSQL

Best regards
JP