I have the following code:
Dim IP, domainName As String
domainName = "yahoo.com"
Try
IP = System.Net.Dns. GetHostByName(d omainName).Addr essList(0).ToSt ring()
Catch ex As Exception
IP = "Not Valid"
End Try
Console.WriteLi ne(IP)
System.Threadin g.Thread.Sleep( 2000)
When it has a resolvable domain, like yahoo.com it responds back instantly
with the ip address. However, if there is a domain in there that does not
exist, like blue2343.com, it takes upwards of 5 seconds to print "Not Valid"
to the screen. Why is that? and is there a way around it?
Thanks,
Scott
Nov 20 '05
22  1561 
Scot,
What happens when you step into the code? Does it takes this long everytime
you run the app, even if the process is not recycled? Charles is saying "I
have noticed that the first time an exception is thrown and caught, a .NET
application can take a significant time (several seconds) before returning
control to the catch block." Have you confirmed this is what is happening
by stepping into the try...catch block?
Raymond Lewallen
"Scot" <bl***@blank.bl ank.com> wrote in message
news:c5******** @library1.airne ws.net... I think Charles is correct in his assumption. I understand that DNS
lookups on non-existant domains take longer, but not in the 3 to 5 second range.
A second or two would be acceptable, but even that would be long if you
there was minimal network latency.
I believe it is something in the Try..Catch segment. Anyone?
"Raymond Lewallen" <Ra************ ******@nospam.f aa.gov> wrote in message
news:Oq******** *****@tk2msftng p13.phx.gbl... Scot,
This is mostly likely due to the time it is taking for your DNS server
to attempt to resolve the DNS name to an IP address. It is not uncommon
for 3-6 seconds to pass while DNS attempts to resolve an entry that does not
exist. There is no way around the time it takes for a DNS server to
exhaust its resources in an attempt to resolve hostnames to ip addresses.
HTH,
Raymond Lewallen
"Scot" <bl***@blank.bl ank.com> wrote in message
news:c5******** @library1.airne ws.net... I have the following code:
Dim IP, domainName As String
domainName = "yahoo.com"
Try
IP =
System.Net.Dns. GetHostByName(d omainName).Addr essList(0).ToSt ring() Catch ex As Exception
IP = "Not Valid"
End Try
Console.WriteLi ne(IP)
System.Threadin g.Thread.Sleep( 2000)
When it has a resolvable domain, like yahoo.com it responds back
instantly with the ip address. However, if there is a domain in there that does not exist, like blue2343.com, it takes upwards of 5 seconds to print "Not
Valid" to the screen. Why is that? and is there a way around it?
Thanks,
Scott
I haven't tried that. Unfortunately I am not an "official" programmer, so I
more or less hack things together until they work. I wouldn't have even the
first bit of a clue as far as how to step into the try....catch block. In
fact this is the first time I have ever used one in vb.net, and it was only
because I couldn't solve the situation another way.
It takes this long everytime I run the app, but it is started from scratch
each time.
"Raymond Lewallen" <Ra************ ******@nospam.f aa.gov> wrote in message
news:eU******** ******@TK2MSFTN GP11.phx.gbl... Scot,
What happens when you step into the code? Does it takes this long
everytime you run the app, even if the process is not recycled? Charles is saying
"I have noticed that the first time an exception is thrown and caught, a .NET
application can take a significant time (several seconds) before returning
control to the catch block." Have you confirmed this is what is happening
by stepping into the try...catch block?
Raymond Lewallen
"Scot" <bl***@blank.bl ank.com> wrote in message
news:c5******** @library1.airne ws.net... I think Charles is correct in his assumption. I understand that DNS
lookups on non-existant domains take longer, but not in the 3 to 5 second range.
A second or two would be acceptable, but even that would be long if you
there was minimal network latency.
I believe it is something in the Try..Catch segment. Anyone?
"Raymond Lewallen" <Ra************ ******@nospam.f aa.gov> wrote in
message news:Oq******** *****@tk2msftng p13.phx.gbl... Scot,
This is mostly likely due to the time it is taking for your DNS server to attempt to resolve the DNS name to an IP address. It is not uncommon for 3-6 seconds to pass while DNS attempts to resolve an entry that does
not exist. There is no way around the time it takes for a DNS server to
exhaust its resources in an attempt to resolve hostnames to ip addresses.
HTH,
Raymond Lewallen
"Scot" <bl***@blank.bl ank.com> wrote in message
news:c5******** @library1.airne ws.net...
> I have the following code:
>
> Dim IP, domainName As String
> domainName = "yahoo.com"
>
> Try
> IP =
System.Net.Dns. GetHostByName(d omainName).Addr essList(0).ToSt ring()
> Catch ex As Exception
> IP = "Not Valid"
> End Try
>
> Console.WriteLi ne(IP)
> System.Threadin g.Thread.Sleep( 2000)
>
>
> When it has a resolvable domain, like yahoo.com it responds back
instantly > with the ip address. However, if there is a domain in there that
does not > exist, like blue2343.com, it takes upwards of 5 seconds to print
"Not Valid"
> to the screen. Why is that? and is there a way around it?
>
> Thanks,
>
> Scott
>
>
I haven't tried that. Unfortunately I am not an "official" programmer, so I
more or less hack things together until they work. I wouldn't have even the
first bit of a clue as far as how to step into the try....catch block. In
fact this is the first time I have ever used one in vb.net, and it was only
because I couldn't solve the situation another way.
It takes this long everytime I run the app, but it is started from scratch
each time.
"Raymond Lewallen" <Ra************ ******@nospam.f aa.gov> wrote in message
news:eU******** ******@TK2MSFTN GP11.phx.gbl... Scot,
What happens when you step into the code? Does it takes this long
everytime you run the app, even if the process is not recycled? Charles is saying
"I have noticed that the first time an exception is thrown and caught, a .NET
application can take a significant time (several seconds) before returning
control to the catch block." Have you confirmed this is what is happening
by stepping into the try...catch block?
Raymond Lewallen
"Scot" <bl***@blank.bl ank.com> wrote in message
news:c5******** @library1.airne ws.net... I think Charles is correct in his assumption. I understand that DNS
lookups on non-existant domains take longer, but not in the 3 to 5 second range.
A second or two would be acceptable, but even that would be long if you
there was minimal network latency.
I believe it is something in the Try..Catch segment. Anyone?
"Raymond Lewallen" <Ra************ ******@nospam.f aa.gov> wrote in
message news:Oq******** *****@tk2msftng p13.phx.gbl... Scot,
This is mostly likely due to the time it is taking for your DNS server to attempt to resolve the DNS name to an IP address. It is not uncommon for 3-6 seconds to pass while DNS attempts to resolve an entry that does
not exist. There is no way around the time it takes for a DNS server to
exhaust its resources in an attempt to resolve hostnames to ip addresses.
HTH,
Raymond Lewallen
"Scot" <bl***@blank.bl ank.com> wrote in message
news:c5******** @library1.airne ws.net...
> I have the following code:
>
> Dim IP, domainName As String
> domainName = "yahoo.com"
>
> Try
> IP =
System.Net.Dns. GetHostByName(d omainName).Addr essList(0).ToSt ring()
> Catch ex As Exception
> IP = "Not Valid"
> End Try
>
> Console.WriteLi ne(IP)
> System.Threadin g.Thread.Sleep( 2000)
>
>
> When it has a resolvable domain, like yahoo.com it responds back
instantly > with the ip address. However, if there is a domain in there that
does not > exist, like blue2343.com, it takes upwards of 5 seconds to print
"Not Valid"
> to the screen. Why is that? and is there a way around it?
>
> Thanks,
>
> Scott
>
>
Scot, set a breakpoint on your GetHostByName line (right-click on the line
and click set breakpoint). When you run the app it will stop there, and
then hit F11 to step into the code line by line and you will see where the
hic-cup is occurring.
Scot, set a breakpoint on your GetHostByName line (right-click on the line
and click set breakpoint). When you run the app it will stop there, and
then hit F11 to step into the code line by line and you will see where the
hic-cup is occurring.
I set the breakpoint on that line, then hit F11.
It highlights Sub Main() in yellow with a yellow arrow to the left.
F11 again, domainName line is now in yellow
F11, Try in yello
F11, breakpoint line in yellow
F11, End Try in yellow
F11, console.writeli ne in yellow
F11, sleep in yellow
then End Sub ends up in yellow
Nothing seems to take the 5 seconds, even when I rapidly go through it with
F11.
"Raymond Lewallen" <Ra************ ******@nospam.f aa.gov> wrote in message
news:ur******** ******@TK2MSFTN GP10.phx.gbl... Scot, set a breakpoint on your GetHostByName line (right-click on the line
and click set breakpoint). When you run the app it will stop there, and
then hit F11 to step into the code line by line and you will see where the
hic-cup is occurring.
I set the breakpoint on that line, then hit F11.
It highlights Sub Main() in yellow with a yellow arrow to the left.
F11 again, domainName line is now in yellow
F11, Try in yello
F11, breakpoint line in yellow
F11, End Try in yellow
F11, console.writeli ne in yellow
F11, sleep in yellow
then End Sub ends up in yellow
Nothing seems to take the 5 seconds, even when I rapidly go through it with
F11.
"Raymond Lewallen" <Ra************ ******@nospam.f aa.gov> wrote in message
news:ur******** ******@TK2MSFTN GP10.phx.gbl... Scot, set a breakpoint on your GetHostByName line (right-click on the line
and click set breakpoint). When you run the app it will stop there, and
then hit F11 to step into the code line by line and you will see where the
hic-cup is occurring.
"Scot" <bl***@blank.bl ank.com> wrote in message
news:c5******** @library1.airne ws.net... I haven't tried that. Unfortunately I am not an "official" programmer,
Ha! don't worry about being an official programmer. I've met "official" or
"profession al" programmers that don't know a damn thing. =)
so I
more or less hack things together until they work. I wouldn't have even
the first bit of a clue as far as how to step into the try....catch block. In
fact this is the first time I have ever used one in vb.net, and it was
only because I couldn't solve the situation another way.
It takes this long everytime I run the app, but it is started from scratch
each time.
"Raymond Lewallen" <Ra************ ******@nospam.f aa.gov> wrote in message
news:eU******** ******@TK2MSFTN GP11.phx.gbl... Scot,
What happens when you step into the code? Does it takes this long
everytime you run the app, even if the process is not recycled? Charles is saying
"I have noticed that the first time an exception is thrown and caught, a
..NET application can take a significant time (several seconds) before
returning control to the catch block." Have you confirmed this is what is
happening by stepping into the try...catch block?
Raymond Lewallen
"Scot" <bl***@blank.bl ank.com> wrote in message
news:c5******** @library1.airne ws.net... I think Charles is correct in his assumption. I understand that DNS
lookups on non-existant domains take longer, but not in the 3 to 5 second
range. A second or two would be acceptable, but even that would be long if you
there was minimal network latency.
I believe it is something in the Try..Catch segment. Anyone?
"Raymond Lewallen" <Ra************ ******@nospam.f aa.gov> wrote in message news:Oq******** *****@tk2msftng p13.phx.gbl...
> Scot,
>
> This is mostly likely due to the time it is taking for your DNS
server to > attempt to resolve the DNS name to an IP address. It is not
uncommon for > 3-6 seconds to pass while DNS attempts to resolve an entry that does
not > exist. There is no way around the time it takes for a DNS server to
exhaust
> its resources in an attempt to resolve hostnames to ip addresses.
>
> HTH,
>
> Raymond Lewallen
>
> "Scot" <bl***@blank.bl ank.com> wrote in message
> news:c5******** @library1.airne ws.net...
> > I have the following code:
> >
> > Dim IP, domainName As String
> > domainName = "yahoo.com"
> >
> > Try
> > IP =
> System.Net.Dns. GetHostByName(d omainName).Addr essList(0).ToSt ring()
> > Catch ex As Exception
> > IP = "Not Valid"
> > End Try
> >
> > Console.WriteLi ne(IP)
> > System.Threadin g.Thread.Sleep( 2000)
> >
> >
> > When it has a resolvable domain, like yahoo.com it responds back
instantly
> > with the ip address. However, if there is a domain in there that does not
> > exist, like blue2343.com, it takes upwards of 5 seconds to print "Not > Valid"
> > to the screen. Why is that? and is there a way around it?
> >
> > Thanks,
> >
> > Scott
> >
> >
>
>
"Scot" <bl***@blank.bl ank.com> wrote in message
news:c5******** @library1.airne ws.net... I haven't tried that. Unfortunately I am not an "official" programmer,
Ha! don't worry about being an official programmer. I've met "official" or
"profession al" programmers that don't know a damn thing. =)
so I
more or less hack things together until they work. I wouldn't have even
the first bit of a clue as far as how to step into the try....catch block. In
fact this is the first time I have ever used one in vb.net, and it was
only because I couldn't solve the situation another way.
It takes this long everytime I run the app, but it is started from scratch
each time.
"Raymond Lewallen" <Ra************ ******@nospam.f aa.gov> wrote in message
news:eU******** ******@TK2MSFTN GP11.phx.gbl... Scot,
What happens when you step into the code? Does it takes this long
everytime you run the app, even if the process is not recycled? Charles is saying
"I have noticed that the first time an exception is thrown and caught, a
..NET application can take a significant time (several seconds) before
returning control to the catch block." Have you confirmed this is what is
happening by stepping into the try...catch block?
Raymond Lewallen
"Scot" <bl***@blank.bl ank.com> wrote in message
news:c5******** @library1.airne ws.net... I think Charles is correct in his assumption. I understand that DNS
lookups on non-existant domains take longer, but not in the 3 to 5 second
range. A second or two would be acceptable, but even that would be long if you
there was minimal network latency.
I believe it is something in the Try..Catch segment. Anyone?
"Raymond Lewallen" <Ra************ ******@nospam.f aa.gov> wrote in message news:Oq******** *****@tk2msftng p13.phx.gbl...
> Scot,
>
> This is mostly likely due to the time it is taking for your DNS
server to > attempt to resolve the DNS name to an IP address. It is not
uncommon for > 3-6 seconds to pass while DNS attempts to resolve an entry that does
not > exist. There is no way around the time it takes for a DNS server to
exhaust
> its resources in an attempt to resolve hostnames to ip addresses.
>
> HTH,
>
> Raymond Lewallen
>
> "Scot" <bl***@blank.bl ank.com> wrote in message
> news:c5******** @library1.airne ws.net...
> > I have the following code:
> >
> > Dim IP, domainName As String
> > domainName = "yahoo.com"
> >
> > Try
> > IP =
> System.Net.Dns. GetHostByName(d omainName).Addr essList(0).ToSt ring()
> > Catch ex As Exception
> > IP = "Not Valid"
> > End Try
> >
> > Console.WriteLi ne(IP)
> > System.Threadin g.Thread.Sleep( 2000)
> >
> >
> > When it has a resolvable domain, like yahoo.com it responds back
instantly
> > with the ip address. However, if there is a domain in there that does not
> > exist, like blue2343.com, it takes upwards of 5 seconds to print "Not > Valid"
> > to the screen. Why is that? and is there a way around it?
> >
> > Thanks,
> >
> > Scott
> >
> >
>
>
Scot,
Not the first time I've seen something like this. I've actually had code
that would throw exceptions when just running through it, but when I stepped
through it, would work just fine! It stinks to say it, but rebooting often
helped that problem (not that it actually occurred on a regular basis). I'm
afraid I have no more advice on the subject, and I hate to leave you with
"Maybe you'll have to live with it", so hopefully someone else will have a
good suggestion.
Sorry I couldn't be of more help,
Raymond Lewallen
"Scot" <bl***@blank.bl ank.com> wrote in message
news:c5******** @library1.airne ws.net... I set the breakpoint on that line, then hit F11.
It highlights Sub Main() in yellow with a yellow arrow to the left.
F11 again, domainName line is now in yellow
F11, Try in yello
F11, breakpoint line in yellow
F11, End Try in yellow
F11, console.writeli ne in yellow
F11, sleep in yellow
then End Sub ends up in yellow
Nothing seems to take the 5 seconds, even when I rapidly go through it
with F11.
"Raymond Lewallen" <Ra************ ******@nospam.f aa.gov> wrote in message
news:ur******** ******@TK2MSFTN GP10.phx.gbl... Scot, set a breakpoint on your GetHostByName line (right-click on the
line and click set breakpoint). When you run the app it will stop there, and
then hit F11 to step into the code line by line and you will see where
the hic-cup is occurring.
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