Sybase NNTP forums - End Of Life (EOL)

The NNTP forums from Sybase - forums.sybase.com - are now closed.

All new questions should be directed to the appropriate forum at the SAP Community Network (SCN).

Individual products have links to the respective forums on SCN, or you can go to SCN and search for your product in the search box (upper right corner) to find your specific developer center.

Connection Sanity Check

4 posts in General Discussion (old) Last posting was on 2000-03-16 20:44:31.0Z
Mark Maslow Posted on 2000-03-16 20:00:10.0Z
Newsgroups: sybase.public.easerver
From: "Mark Maslow" <mark.maslow@sierraclub.org>
Subject: Connection Sanity Check
Date: Thu, 16 Mar 2000 12:00:10 -0800
Lines: 18
Organization: Sierra Club
X-Priority: 3
X-MSMail-Priority: Normal
X-Newsreader: Microsoft Outlook Express 5.00.2314.1300
X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2314.1300
NNTP-Posting-Host: machine001.sierraclub.org 207.90.163.1
Message-ID: <347_p5$KsM4j$GA.261@forums.sybase.com>
Path: forums-1-dub!forums-1-dub!forums-master.sybase.com!forums.sybase.com
Xref: forums-1-dub sybase.public.easerver:26254
Article PK: 156922

I wonder if someone can explain just what the "Enable connection sanity
check" for a connection cache does.

The doc says "Determines whether connections released by components should
be validated before reuse is allowed". Does this mean that, if sanity check
is disabled, the server allows reuse of possibly bad connections? Huh?

The doc also says disabling increases performance, but may complicate
debugging. Debugging what, exactly? Does that mean that, once an
application has been in production and seems to be stable, you should
disable the sanity check? Or might certain information that might help
determine the cause of a production error be lost?

TIA for clearing up my confusion on this point.

Mark Maslow


Dave Wolf [Sybase] Posted on 2000-03-16 20:26:24.0Z
Newsgroups: sybase.public.easerver
From: "Dave Wolf [Sybase]" <dwolf@sybase.com>
Subject: Re: Connection Sanity Check
Date: Thu, 16 Mar 2000 15:26:24 -0500
Lines: 36
X-Priority: 3
X-MSMail-Priority: Normal
X-Newsreader: Microsoft Outlook Express 5.00.2919.6600
X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2919.6600
NNTP-Posting-Host: vpn-eme-045.sybase.com 130.214.8.45
Message-ID: <347_bqcd#Z4j$GA.111@forums.sybase.com>
References: <347_p5$KsM4j$GA.261@forums.sybase.com>
Path: forums-1-dub!forums-1-dub!forums-master.sybase.com!forums.sybase.com
Xref: forums-1-dub sybase.public.easerver:26252
Article PK: 156921

Its pretty simple really. When enabled the cache will execute a SQL
statement on the connection everytime you request it from the cache. By
default we send "SELECT 1". If this statement works we return you the
connection. If it fails we assume the connection is bad and destroy it and
create a replacement.

This makes sure that you dont get handed an already dead connection from the
pool. Like if the DB shutdown or if it went stale.

Dave Wolf
Internet Applications Division

"Mark Maslow" <mark.maslow@sierraclub.org> wrote in message
news:p5$KsM4j$GA.261@forums.sybase.com...
> I wonder if someone can explain just what the "Enable connection sanity
> check" for a connection cache does.
>
> The doc says "Determines whether connections released by components should
> be validated before reuse is allowed". Does this mean that, if sanity
check
> is disabled, the server allows reuse of possibly bad connections? Huh?
>
> The doc also says disabling increases performance, but may complicate
> debugging. Debugging what, exactly? Does that mean that, once an
> application has been in production and seems to be stable, you should
> disable the sanity check? Or might certain information that might help
> determine the cause of a production error be lost?
>
> TIA for clearing up my confusion on this point.
>
> Mark Maslow
>
>


Mark Maslow Posted on 2000-03-16 20:33:49.0Z
Newsgroups: sybase.public.easerver
From: "Mark Maslow" <mark.maslow@sierraclub.org>
Subject: Re: Connection Sanity Check
Date: Thu, 16 Mar 2000 12:33:49 -0800
Lines: 49
Organization: Sierra Club
X-Priority: 3
X-MSMail-Priority: Normal
X-Newsreader: Microsoft Outlook Express 5.00.2314.1300
X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2314.1300
NNTP-Posting-Host: machine001.sierraclub.org 207.90.163.1
Message-ID: <347_8g$dff4j$GA.151@forums.sybase.com>
References: <347_p5$KsM4j$GA.261@forums.sybase.com> <347_bqcd#Z4j$GA.111@forums.sybase.com>
Path: forums-1-dub!forums-1-dub!forums-master.sybase.com!forums.sybase.com
Xref: forums-1-dub sybase.public.easerver:26251
Article PK: 156919

Thanks Dave. Sounds to me like disabling the sanity check would be asking
for trouble. Under what circumstances would one want to disable sanity
check?

Mark Maslow

Dave Wolf [Sybase] <dwolf@sybase.com> wrote in message
news:bqcd#Z4j$GA.111@forums.sybase.com...
> Its pretty simple really. When enabled the cache will execute a SQL
> statement on the connection everytime you request it from the cache. By
> default we send "SELECT 1". If this statement works we return you the
> connection. If it fails we assume the connection is bad and destroy it
and
> create a replacement.
>
> This makes sure that you dont get handed an already dead connection from
the
> pool. Like if the DB shutdown or if it went stale.
>
> Dave Wolf
> Internet Applications Division
>
>
> "Mark Maslow" <mark.maslow@sierraclub.org> wrote in message
> news:p5$KsM4j$GA.261@forums.sybase.com...
> > I wonder if someone can explain just what the "Enable connection sanity
> > check" for a connection cache does.
> >
> > The doc says "Determines whether connections released by components
should
> > be validated before reuse is allowed". Does this mean that, if sanity
> check
> > is disabled, the server allows reuse of possibly bad connections? Huh?
> >
> > The doc also says disabling increases performance, but may complicate
> > debugging. Debugging what, exactly? Does that mean that, once an
> > application has been in production and seems to be stable, you should
> > disable the sanity check? Or might certain information that might help
> > determine the cause of a production error be lost?
> >
> > TIA for clearing up my confusion on this point.
> >
> > Mark Maslow
> >
> >
>
>


Dave Wolf [Sybase] Posted on 2000-03-16 20:44:31.0Z
Newsgroups: sybase.public.easerver
From: "Dave Wolf [Sybase]" <dwolf@sybase.com>
Subject: Re: Connection Sanity Check
Date: Thu, 16 Mar 2000 15:44:31 -0500
Lines: 64
X-Priority: 3
X-MSMail-Priority: Normal
X-Newsreader: Microsoft Outlook Express 5.00.2919.6600
X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2919.6600
NNTP-Posting-Host: vpn-eme-045.sybase.com 130.214.8.45
Message-ID: <347_tgaVGk4j$GA.261@forums.sybase.com>
References: <347_p5$KsM4j$GA.261@forums.sybase.com> <347_bqcd#Z4j$GA.111@forums.sybase.com> <347_8g$dff4j$GA.151@forums.sybase.com>
Path: forums-1-dub!forums-1-dub!forums-master.sybase.com!forums.sybase.com
Xref: forums-1-dub sybase.public.easerver:26250
Article PK: 156917

If you were pretty confident that connections wouldnt go bad AND you cant
stand the overhead of the one sql statement we'll send. I turn it off in
benchmarks and the such, otherwise Id leave it on myself. We all know that
database connections can and will just go stale eventually.

Dave Wolf
Internet Applications Division

"Mark Maslow" <mark.maslow@sierraclub.org> wrote in message
news:8g$dff4j$GA.151@forums.sybase.com...
> Thanks Dave. Sounds to me like disabling the sanity check would be asking
> for trouble. Under what circumstances would one want to disable sanity
> check?
>
> Mark Maslow
>
> Dave Wolf [Sybase] <dwolf@sybase.com> wrote in message
> news:bqcd#Z4j$GA.111@forums.sybase.com...
> > Its pretty simple really. When enabled the cache will execute a SQL
> > statement on the connection everytime you request it from the cache. By
> > default we send "SELECT 1". If this statement works we return you the
> > connection. If it fails we assume the connection is bad and destroy it
> and
> > create a replacement.
> >
> > This makes sure that you dont get handed an already dead connection from
> the
> > pool. Like if the DB shutdown or if it went stale.
> >
> > Dave Wolf
> > Internet Applications Division
> >
> >
> > "Mark Maslow" <mark.maslow@sierraclub.org> wrote in message
> > news:p5$KsM4j$GA.261@forums.sybase.com...
> > > I wonder if someone can explain just what the "Enable connection
sanity
> > > check" for a connection cache does.
> > >
> > > The doc says "Determines whether connections released by components
> should
> > > be validated before reuse is allowed". Does this mean that, if sanity
> > check
> > > is disabled, the server allows reuse of possibly bad connections?
Huh?
> > >
> > > The doc also says disabling increases performance, but may complicate
> > > debugging. Debugging what, exactly? Does that mean that, once an
> > > application has been in production and seems to be stable, you should
> > > disable the sanity check? Or might certain information that might
help
> > > determine the cause of a production error be lost?
> > >
> > > TIA for clearing up my confusion on this point.
> > >
> > > Mark Maslow
> > >
> > >
> >
> >
>
>