FreeTDS Development Group

["Wagner, Steve" <Steve.Wagner AT 49ers.com>]

Right, that was fairly obvious.  The question is why these errors started 
showing up after working fine for 2+ years.

Steve

-----Original Message-----
From: FreeTDS [mailto:freetds-bounces AT lists.ibiblio.org] On Behalf Of 
Frediano Ziglio
Sent: Saturday, December 16, 2017 9:18 AM
To: FreeTDS Development Group <freetds AT lists.ibiblio.org>
Subject: Re: [freetds] DB-Lib error message 20017, severity 9:Unexpected EOF 
from the server

2017-11-28 21:40 GMT+00:00 Wagner, Steve <Steve.Wagner AT 49ers.com>:
> We've been using pymssql and FreeTDS for over 2 years now without problems. 
>  We recently upgraded pymssql to 2.1.3 and also from Python 3.4 to 3.6.  
> Since that upgrade we've been getting the following error intermittently 
> (but frequently).
>
> (20017, b'DB-Lib error message 20017, severity 9:\nUnexpected EOF from 
> the server (FBOps-Prod:1433)\nDB-Lib error message 20002, severity 
> 9:\nAdaptive Server connection failed (FBOps-Prod:1433)\n')
>

This usually means server closed the connection. This can happen if there's a 
firewall between or if client send some garbage.

> There is no apparent pattern to the failures that we have been able to 
> discover.  Well over 95% of the DB calls succeed.  It can fail on any 
> stored proc or sql query.
>
> The database calls apparently do not even get to the database because 
> nothing shows up in any DB log or trace.
>
> I've scoured the web and come up empty.
>
> I've reinstalled pymssql and FreeTDS but it still fails.
>
> Failures occur when connected to a DB server that is remote to the app but 
> when connected to localhost.
>
> I've checked max number of connections and it's 4096 which should be plenty 
> as there are no more than 10 active users at a time.
>
> Below is an excerpt from the TDS log file (full log file at the end).
>
>
> packet.c:639:Received packet
>
>
.......
>
>
> dblib.c:6845:dbsqlsend(000000000775B3B0)
>
>
> mem.c:648:tds_free_all_results()
>
>
> util.c:165:Changed query state from IDLE to WRITING
>
>
> util.c:165:Changed query state from WRITING to PENDING
>
>
> packet.c:740:Sending packet
>
>
> 0000 01 01 00 1c 00 00 01 00-42 00 45 00 47 00 49 00 |........ 
> B.E.G.I.|
>
>
> 0010 4e 00 20 00 54 00 52 00-41 00 4e 00             |N. .T.R. A.N.|
>
>
>
>
> dblib.c:4625:dbsqlok(000000000775B3B0)
>
>
> dblib.c:4654:dbsqlok() not done, calling tds_process_tokens()
>
>
> token.c:550:tds_process_tokens(00000000075359E0, 000000000A58BBA8, 
> 000000000A58BBA0, 0x6914)
>
>
> util.c:165:Changed query state from PENDING to READING
>
>
> packet.c:639:Received packet
>
>
> 0000 04 01 00 11 00 4e 01 00-fd 00 00 d4 00 00 00 00 |.....N.. 
> ........|
>
>
> 0010 00                     -                        |.|
>
>

Here server replied correctly so accepted the query.

>
>
> token.c:565:processing result tokens.  marker is  fd(DONE)
>
>
> token.c:2081:tds_process_end: more_results = 0
>
>
>       was_cancelled = 0
>
>
>       error = 0
>
>
>       done_count_valid = 0
>
>
> token.c:2098:                rows_affected = 0
>
>
> token.c:2101:tds_process_end() state set to TDS_IDLE
>
>
> util.c:165:Changed query state from READING to IDLE
>
>
> util.c:83:logic error: cannot change query state from IDLE to PENDING
>
>
> util.c:165:Changed query state from IDLE to IDLE
>
>
> dblib.c:4687:dbsqlok() end status is SUCCEED
>
>
> dblib.c:4698:dbsqlok() end status was success
>
>
> dblib.c:1689:dbresults(000000000775B3B0)
>
>
> dblib.c:1694:dbresults: dbresults_state is 5 (_DB_RES_SUCCEED)
>
>
> dblib.c:1679:dbresults returning 1 (SUCCEED)
>
>
> dblib.c:2772:dbcount(000000000775B3B0)
>
>
> dblib.c:3203:dbcancel(000000000775B3B0)
>
>
> query.c:2189:tds_send_cancel: not in_cancel and idle
>
>
> dblib.c:1463:dbclose(000000000775B3B0)
>

Here client is closing the connection, in this case there's no "Unexpected 
EOF".

>
> dblib.c:243:dblib_del_connection(000007FEF8B0FA70, 00000000075359E0)
>
>
> query.c:3772:tds_disconnect()
>
>
> util.c:165:Changed query state from IDLE to DEAD
>
>
> mem.c:648:tds_free_all_results()
>
>
> dblib.c:290:dblib_release_tds_ctx(1)
>
>
> dblib.c:5873:dbfreebuf(000000000775B3B0)
>
>
> Steve
>

Looks like this log is correct and do not present the error you are reporting.

Frediano
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