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Question and Answer

Tom Kyte

Thanks for the question, Roger.

Asked: July 29, 2006 - 10:26 pm UTC

Last updated: August 27, 2006 - 3:45 pm UTC

Version: 10.2.0.2.0

Viewed 1000+ times

You Asked

Hi Tom

How can I know how many dedicated sessions one listener can handle if this server only has this listener.
If I found that one listener is the bottleneck of system, is it helpful that I add another one listener to system?

Thanks



and Tom said...

the listener does not handle dedicated servers. It creates them, hands off the connection and loses touch with them.

The listener could be impacted by a "logon storm" - where thousands of users try to simultaneously log in at the same time.

But even then, doubtful that multiple listeners would help as this would be a system very much under stress at that point. The act of process creation is heavy duty and the OS would be spending much of it's time doing that. The network card would be getting hit with inbound connections (and there is probably only one of those).

No, you would not generally use multiple listeners in order to "scale out".

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Comments

More questions about listener

A reader, July 30, 2006 - 9:54 am UTC

Hi Tome

Now the question should be how to estimate how many concurrent logons a listener can handle?
If I have 4 network cards with 4 ip addresses and 4 instances, which following solution is better then
1. 4 listeners bind 4 nic and 4 ips
2. 1 listener with 4 ip?

Thanks

Tom Kyte
July 30, 2006 - 1:30 pm UTC

is this "for real" or "for example"

if you have 4 nics, you must have a massive implementation - tell us more, do you expect login storms?

Multiple Nics

A reader, July 30, 2006 - 9:31 pm UTC

Hi Tom

Actually, it's FOR REAL, we have 4 nics which connect 4 VLANs which are isolated each other. That means we must have one listener to handle the requests from each vlan, but I think one listener with 4 IPs can do this too, but I don't know the difference in performance
Thanks

Tom Kyte
July 31, 2006 - 7:41 am UTC

do you have login storms or not. If not, one listener should more than suffice. If so, you'd need the physical resources to do the process creation (that is heavy duty) before you'd need multiple listeners.

Multiple Nics

A reader, July 31, 2006 - 8:30 am UTC

Hi Tom

There won't be logon storm.
If what I understand is correct, the capacity of system, like how many concurrent session one listener can hand off and how many sessions the server can handle, should rely on power of hardware, if the power is strong enough, the numbers of sessions and processes will not be the matter.

Thanks

In my humble opinion

A reader, July 31, 2006 - 9:11 am UTC

You should be looking at connection pooling.

Tom Kyte
July 31, 2006 - 10:12 am UTC

why? opinions should come with some reasoning.

Why would connection pooling (I'm assuming Oracle connection pooling) be something to be looked at given the information here?

4 nics + 4 vlans = 4 listeners

A reader, August 23, 2006 - 11:14 am UTC

I would prefer 4 listeners in that case so that I (he) can turn on/off every VLAN nicely (remember that protocol.ora doesn't support wildcards). comments?

Tom Kyte
August 27, 2006 - 3:45 pm UTC

it would be up to you, you don't need to, but you can.

Oracle exception on Listener even though connection pooling is used?

Tom, March 12, 2007 - 12:45 pm UTC

Hi,

I was just wondering if the following exception is due to the Oracle 10g setup. Our application is running on Websphere and 150 connections have been setup in the max pool size. The following exception was thrown during a 150 user stress testing. Any idea?

Listener refused the connection with the following error:
ORA-12519, TNS:no appropriate service handler found
The Connection descriptor used by the client was:
10.0.101.68:1521:calms210g
DSRA0010E: SQL State = null, Error Code = 0DSRA0010E: SQL State = null, Error Code = 0

Oracle exception on Listener even though connection pooling is used?

Tom, March 12, 2007 - 12:45 pm UTC

Hi,

I was just wondering if the following exception is due to the Oracle 10g setup. Our application is running on Websphere and 150 connections have been setup in the max pool size. The following exception was thrown during a 150 user stress testing. Any idea?

Listener refused the connection with the following error:
ORA-12519, TNS:no appropriate service handler found
The Connection descriptor used by the client was:
10.0.101.68:1521:calms210g
DSRA0010E: SQL State = null, Error Code = 0DSRA0010E: SQL State = null, Error Code = 0

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