Re: Unexpected connects and disconnects at the DB server.
Michael Peppler <[email protected]> Wed, 8 Oct 2008 07:15:54 +0200
| Newsgroups | gmane.comp.lang.perl.modules.dbi.sybase |
|---|---|
| Message-ID | <[email protected]> |
--Apple-Mail-40-322618982 Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Content-Transfer-Encoding: 7bit On Oct 7, 2008, at 10:28 PM, [email protected] wrote: > > Guys, > > Solaris > DBD Sybase 1.05 > > My co-workers code has a single dbh->connect. > (he has a log/timestamp showing where he only calling it once.) > > The sybase sysaudits show repeated login/select/logouts. > The perl code is believed to simply run multiple prepare/executes. > > The logouts are occurring 6 millisecs after the select statement yet > his code does not have any explicit disconnect logic. > > Any ideas? > Yes :-) What happens is that DBD::Sybase is opening a second connection "under the covers" because the query on the primary connection is still considered "active" when another query is initiated. You can easily see this if you run DBD::Sybase with DBI->trace(5). In DBD::Sybase 1.08 you can set a database connection attribute that prohibits opening secondary connections in this way. In addition newer versions of DBD::Sybase are better at clearing results from a query. Michael -- Michael Peppler - Peppler Consulting SaRL [email protected] - http://www.peppler.org Sybase DBA/Developer - TeamSybase: http://www.teamsybase.com Sybase on Linux FAQ - http://www.peppler.org/FAQ/linux.html --Apple-Mail-40-322618982 Content-Type: text/html; charset=US-ASCII Content-Transfer-Encoding: quoted-printable <html><body style=3D"word-wrap: break-word; -webkit-nbsp-mode: space; = -webkit-line-break: after-white-space; "><br><div><div>On Oct 7, 2008, = at 10:28 PM, <a = href=3D"mailto:[email protected]">CSane@EvergreenInvestments.= com</a> wrote:</div><br class=3D"Apple-interchange-newline"><blockquote = type=3D"cite"><br><font size=3D"2" face=3D"sans-serif">Guys,</font> <br> = <br><font size=3D"2" face=3D"sans-serif">Solaris</font> <br><font = size=3D"2" face=3D"sans-serif">DBD Sybase 1.05</font> <br> <br><font = size=3D"2" face=3D"sans-serif">My co-workers code has a single = dbh->connect. </font> <br><font size=3D"2" face=3D"sans-serif">(he has a = log/timestamp showing where he only calling it once.)</font> <br> = <br><font size=3D"2" face=3D"sans-serif">The sybase sysaudits show = repeated login/select/logouts.</font> <br><font size=3D"2" = face=3D"sans-serif">The perl code is believed to simply run multiple = prepare/executes.</font> <br> <br><font size=3D"2" face=3D"sans-serif">The= logouts are occurring 6 millisecs after the select statement yet his = code does not have any explicit disconnect logic.</font> <br> <br><font = size=3D"2" face=3D"sans-serif">Any ideas?</font> <br><font size=3D"2" = face=3D"sans-serif"><br></font></blockquote><div><br></div><div>Yes = :-)</div><div><br></div><div>What happens is that DBD::Sybase is opening = a second connection "under the covers" because the query on the primary = connection is still considered "active" when another query is = initiated.</div><div><br></div><div>You can easily see this if you run = DBD::Sybase with DBI->trace(5).</div><div><br></div><div>In DBD::Sybase = 1.08 you can set a database connection attribute that prohibits opening = secondary connections in this way. In addition newer versions of = DBD::Sybase are better at clearing results from a = query.</div><div><br></div><div>Michael</div><div>--</div></div><div = apple-content-edited=3D"true"> <span class=3D"Apple-style-span" = style=3D"border-collapse: separate; color: rgb(0, 0, 0); font-family: = Helvetica; font-size: 12px; font-style: normal; font-variant: normal; = font-weight: normal; letter-spacing: normal; line-height: normal; = orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; = white-space: normal; widows: 2; word-spacing: 0px; = -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: = 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: = auto; -webkit-text-stroke-width: 0; "><div style=3D"word-wrap: = break-word; -webkit-nbsp-mode: space; -webkit-line-break: = after-white-space; "><div><div>Michael Peppler = - = Peppler Consulting = SaRL</div><div>[email protected] - = <a = href=3D"http://www.peppler.org">http://www.peppler.org</a></div><div>Sybas= e DBA/Developer - = TeamSybase: <a = href=3D"http://www.teamsybase.com">http://www.teamsybase.com</a></div><div= >Sybase on Linux FAQ - = <a = href=3D"http://www.peppler.org/FAQ/linux.html">http://www.peppler.org/FAQ/= linux.html</a></div><div><br></div></div></div></span><br = class=3D"Apple-interchange-newline"> </div><br></body></html>= --Apple-Mail-40-322618982--