2321996 - 'drop connection' command against some connections didn't work at all.

'drop connection' command against some active sessions didn't work at all.
Those sessions were building so much big versioning space and the IQ server had to be restarted.
 
 1) It was to prevent a versioning space from being increased contiguously by those sessions.

But, the dropped sessions were still alive until the IQ server got restarted.
Below is a sample message log and srvlog out of them.

[iqmsg]
I. 05/17 19:10:03. 0000191317 Collation 949KOR, Case Respect, Blank Padding On, Comparisons are Conditioned
I. 05/17 19:10:03. 0000191317 Txn 276719841 0 276200369
I. 05/17 19:10:03. 0000191317 Connect: SA connHandle: 10863 SA connID: 31 IQ connID: 0000191317 User: user001
...............
I. 05/17 19:10:05. 0000191317 Txn 276719855 0 276200369
I. 05/17 22:06:04. 0000000000 Cancellation request received: SA connHandle: 10863 SA connID: 31 IQ connID: 0000191317 User: user001

[srvlog]
I. 05/17 19:10:05. <,10863,PREPARE,select distinct "SQL1"."COL1" as "COL1","SQL1"."COL2" as "COL1", ......................
I. 05/17 19:10:05. >,10863,PREPARE,131080
I. 05/17 19:10:05. <,10863,OPEN,131080
I. 05/17 19:10:05. >,10863,OPEN,65545

2) The output of netstat command shows some tcp connections were in 'CLOSE_WAIT' as below. 
    IP address of those connections is the host's one which the above query ran.

tcp 0 0 10.10.10.10.2639 10.10.10.11.33950 CLOSE_WAIT
tcp 0 0 10.10.10.10.2639 10.10.10.11.45049 CLOSE_WAIT
tcp 0 0 10.10.10.10.2639 10.10.10.11.53548 CLOSE_WAIT
tcp 0 0 10.10.10.10.2639 10.10.10.11.58991 CLOSE_WAIT
tcp 0 0 10.10.10.10.2639 10.10.10.11.54451 CLOSE_WAIT
tcp 0 0 10.10.10.10.2639 10.10.10.11.60106 CLOSE_WAIT
tcp 0 0 10.10.10.10.2639 10.10.10.11.60103 CLOSE_WAIT

3) According to the output of sp_iqconnection, all the sessions above were in 'OPENCURSOR'.

ConnHandle Name Userid LastReqTime ReqType IQCmdType
10863 SQL_DBC_300f0400 user001 2016-05-17 21:50:05 FETCH OPENCURSOR
10876 SQL_DBC_4846bc00 user001 2016-05-17 21:53:18 FETCH OPENCURSOR
10957 SQL_DBC_5311f800 user001 2016-05-17 21:53:12 FETCH OPENCURSOR
10960 SQL_DBC_49634400 user001 2016-05-17 21:51:37 FETCH OPENCURSOR
11019 SQL_DBC_4f9f7800 user001 2016-05-17 21:46:18 FETCH OPENCURSOR
11195 SQL_DBC_46164800 user002 2016-05-18 0:25:44 FETCH OPENCURSOR
11207 SQL_DBC_4fa40400 user001 2016-05-17 22:01:25 FETCH OPENCURSOR

    
         
4) CR 793679 had been filed for the same problem in IQ 15.4 ESD5, but it still has been opened.

SAP IQ 16.0 SP10 PL15

SAP IQ, IQ, drop connection, CR 799027, CR799027, 799027 , KBA , BC-SYB-IQ , Sybase IQ , Problem