Re: DB-Lib error message 20017, severity 9:Unexpected EOF from the server

2017-11-28 21:40 GMT+00:00 Wagner, Steve <[email protected]>:
> 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
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>
.......
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>
> dblib.c:6845:dbsqlsend(000000000775B3B0)
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>
> mem.c:648:tds_free_all_results()
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>
> util.c:165:Changed query state from IDLE to WRITING
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>
> util.c:165:Changed query state from WRITING to PENDING
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>
> 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)
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>
> dblib.c:4654:dbsqlok() not done, calling tds_process_tokens()
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>
> 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
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>
> 0000 04 01 00 11 00 4e 01 00-fd 00 00 d4 00 00 00 00 |.....N.. ........|
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>
> 0010 00                     -                        |.|
>
>

Here server replied correctly so accepted the query.

>
>
> token.c:565:processing result tokens.  marker is  fd(DONE)
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>
> token.c:2081:tds_process_end: more_results = 0
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>
>       was_cancelled = 0
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>
>       error = 0
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>
>       done_count_valid = 0
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>
> token.c:2098:                rows_affected = 0
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>
> token.c:2101:tds_process_end() state set to TDS_IDLE
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>
> util.c:165:Changed query state from READING to IDLE
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>
> util.c:83:logic error: cannot change query state from IDLE to PENDING
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>
> util.c:165:Changed query state from IDLE to IDLE
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>
> dblib.c:4687:dbsqlok() end status is SUCCEED
>
>
> dblib.c:4698:dbsqlok() end status was success
>
>
> dblib.c:1689:dbresults(000000000775B3B0)
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>
> dblib.c:1694:dbresults: dbresults_state is 5 (_DB_RES_SUCCEED)
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> dblib.c:1679:dbresults returning 1 (SUCCEED)
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>
> dblib.c:2772:dbcount(000000000775B3B0)
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>
> dblib.c:3203:dbcancel(000000000775B3B0)
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>
> query.c:2189:tds_send_cancel: not in_cancel and idle
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>
> 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)
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>
> query.c:3772:tds_disconnect()
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>
> util.c:165:Changed query state from IDLE to DEAD
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>
> mem.c:648:tds_free_all_results()
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>
> dblib.c:290:dblib_release_tds_ctx(1)
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>
> dblib.c:5873:dbfreebuf(000000000775B3B0)
>
>
> Steve
>

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

Frediano