manually closing DB connections...required?

[darrel]

We're running into a problem on our new site. Once a week or so, our site
goes down with an 'out of memory error'. Rebooting the web server fixes
things. Googling the error doesn't return many results (one, actually) and
the suggested fix is to make sure you are manually closing all DB
connections. I'm doing that now, but I had thought that asp.net had fairly
robust automated cleanup, and that having to explicitely close every
connection wasn't necessarily needed (though I certainly agree that it's
good practice). Just curious as to what .net's clean-up capabilities
actually are.

-Darrel

[Kevin Spencer]

Hi darrel,

It's not a matter of .Net's cleanup capabilities. It's a matter of the
nature of database connections in .Net. What I mean is that it has nothing
to do with global .Net operations, such as garbage collection. It is
specific to database connections, due to their nature. You will find the
same type of thing with .Net classes that open and close files, and use
unmanaged resources "under the hood". For example, if you open a file, you
had better close it, or it will become unusable (until the next reboot).
Why? Because that's how the file system works. It locks files when they are
opened, and unlocks them when they are closed. A database connection is
similar, in that, you can open it and it will remain open (and in memory)
until you close it. While the connection at your end may be unused when
you're finished using it, it is still connected to the database at the other
end. Closing it disconnects it, allowing it to be cleaned up.

--
HTH,
Kevin Spencer
..Net Developer
Microsoft MVP
I get paid good money to
solve puzzles for a living

"darrel" <no*****@hotmail.com> wrote in message
news:u0**************@TK2MSFTNGP12.phx.gbl...

We're running into a problem on our new site. Once a week or so, our site
goes down with an 'out of memory error'. Rebooting the web server fixes
things. Googling the error doesn't return many results (one, actually) and
the suggested fix is to make sure you are manually closing all DB
connections. I'm doing that now, but I had thought that asp.net had fairly
robust automated cleanup, and that having to explicitely close every
connection wasn't necessarily needed (though I certainly agree that it's
good practice). Just curious as to what .net's clean-up capabilities
actually are.

-Darrel

[darrel]

> While the connection at your end may be unused when

you're finished using it, it is still connected to the database at the other end. Closing it disconnects it, allowing it to be cleaned up.

While we're on this topic...is there a log anywhere or any way to see the
current open DB connections?

-Darrel

[darrel]

> While the connection at your end may be unused when

you're finished using it, it is still connected to the database at the other end. Closing it disconnects it, allowing it to be cleaned up.

Yikes! Wow...we screwed this one up, then. ;o)

Ok, I'm halfway through closing all our connections. This is definitely the
problem (and our fault). Thanks for clarifying that for me!

-Darrel

[darrel]

Oh...one more question...what is the '= nothing' for, and is that something
I should have as well?

For instance, I had:

objConnect.open()

I am now adding:
objConnect.close()

but should I also add:

objConnect = nothing

-Darrel

[Kevin Spencer]

Hi Darrel,

The following .Net SDK article should be helpful. Along with describing
Connection Pooling, it provides several performanc counters that you can use
to view Connections:

http://msdn.microsoft.com/library/de...taProvider.asp

--
HTH,
Kevin Spencer
..Net Developer
Microsoft MVP
I get paid good money to
solve puzzles for a living

"darrel" <no*****@hotmail.com> wrote in message
news:#R**************@tk2msftngp13.phx.gbl...

While the connection at your end may be unused when
you're finished using it, it is still connected to the database at the

other

end. Closing it disconnects it, allowing it to be cleaned up.

While we're on this topic...is there a log anywhere or any way to see the
current open DB connections?

-Darrel

[Kevin Spencer]

Hi Darrel,

No, that' s not necessary.

--
HTH,
Kevin Spencer
..Net Developer
Microsoft MVP
I get paid good money to
solve puzzles for a living

"darrel" <no*****@hotmail.com> wrote in message
news:Od*************@TK2MSFTNGP09.phx.gbl...

Oh...one more question...what is the '= nothing' for, and is that something I should have as well?

For instance, I had:

objConnect.open()

I am now adding:
objConnect.close()

but should I also add:

objConnect = nothing

-Darrel

[darrel]

> Hi Darrel,

No, that' s not necessary.

Thanks, Kevin!

-Darrel