[Openroad-users] vnodeless connection in OpenROAD 4.1 ?

Sat Dec 9 05:00:11 EST 2006

Hello Anthony,

Dynamic Vnodes bypass the Ingres Name Server.  Normally, the vnode is resolved by the local Name Server.  The local Name Server returns the string that the client then uses to make the connection.  The string returned by the Name Server is identical to Dynamic Vnode.

I would be curious if you could perform a test.  Since it looks like you are using Dynamic vnodes primarily to pass userid and passwords, try the following to see if load balancing still works,

1.	Define a vnode as normal, with an invalid userid and password.
2.	Override the userid and password in the vnode using the following syntax,

myvnode[userid,password]::mydatabase/ingres

Let the group know the results.

Durwin Wright | Sr. Architect | Durwin.Wright at ingres.com <mailto:Durwin.Wright at ingres.com>  | Ingres | 500 Arguello Street | Suite 200 | Redwood City | CA | 94063 | USA <http://maps.google.com/maps?q=500+arguello+street,+94063&ll=37.487297,-122.233200&spn=0.004602,0.012771&t=k&hl=en>   +1 650-587-5523 | fax: +1 650-587-5550 

________________________________

From: openroad-users-bounces at peerlessit.com [mailto:openroad-users-bounces at peerlessit.com] On Behalf Of Anthony Bolton
Sent: Friday, December 08, 2006 9:07 AM
To: International OpenROAD Users
Subject: Re: [Openroad-users] vnodeless connection in OpenROAD 4.1 ?

Hi,

I've also noticed that Dynamic Vnodes don't give you the load balancing that you would get if you used standard vnodes defined in Ingres Net.

If your server has multiple iigcc processes running, each one is available for client connections under the listener aliases II0, II1, II2 etc. But if you just set the listen address in your vnode to II, Ingres Net will automatically load balance across the listeners and switch to a different listener if the first one it tries is full. (I've also been told by Ingres that it does automatic failover to a different listener if the first connection fails). This is useful if you have '000s of clients, as they can all be configured with a listen address of II and Ingres Net balances the connection load across the iigccs for you.

If you use dynamic vnodes then I've found you have to specify explicitly which listener you want - if you specify II it defaults to II0 and never touches the other listeners. Hence the first few hundred users to logon are fine, but once the inbound connection limit is reached on II0 all further connections are refused.

NB. These observations are from OP4.1/SP3 with Ingres 2.6 Net, it may behave differently in OR2006/Ingres 2006.

On a slight tangent - from OR2006 you'll be able to use the Ingres Net from Ingres 2006, which brings back the old IIPROMPTALL functionality for vnodes.

HTH.

Anthony.

Anthony Bolton

phone: +44 (0)1225 475000, email: anthony.bolton at ipl.com <mailto:anthony.bolton at ipl.com> 

www.ipl.com <http://www.ipl.com/> 

________________________________

From: openroad-users-bounces at peerlessit.com [mailto:openroad-users-bounces at peerlessit.com] On Behalf Of Durwin Wright
Sent: 08 December 2006 16:07
To: International OpenROAD Users
Cc: users at lists.ingres.com
Subject: **IPLBATH** Re: [Openroad-users] vnodeless connection in OpenROAD 4.1 ?

Hello Rune,

There is a problem in Ingres 2.6 with Dynamic Vnodes.  A crash happens when the length of a vnode exceeds 64 bytes.  This is true of all vnodes.  When using Dynamic Vnodes, it is more likely that the length will be greater than 64 bytes.

Here is the description of this problem,

Overview: 

        Bug 115280

        Buffer overrun in FRS with vnodeless connection strings 

        because they are generally longer; this occasionally causes 

        crashes in OpenROAD (and Ingres forms applications).  

Release Notes: 

        (GENERIC)

        OpenROAD and Ingres forms-based applications crash 

        intermittently when connecting with a vnodeless 

        connection string (aka dynamic vnode). 

I have referred to this feature as "Dynamic Vnodes" instead of "Vnodeless".  I created a simple OpenROAD application that generates the dynamic vnode strings and does simple connection tests.  I found the documentation to be a little difficult to understand.  

When I started using this application, I found that Dynamic Vnode entries can be used to override the contents of an existing vnode.  This means that if your use of Dyanmic Vnodes is primarily to supply a userid and password for a connection request, then you could create a vnode that has an invalid userid and password and then use the dynamic vnode syntax to override the entry.

So if you have a vnode defined and use the following to connect to an Ingres database

            myvnode::mydatabase/ingres

Then you can use the following in your program to override the userid and password stored in the "myvnode" entry

            myvnode[myuserid,mypassword]::mydatabase/ingres

If you can use this technique, then you should be able to drop below the 64 byte length in the dynamic vnode that you specify.

I suggest that you try sending a vnode entry that is longer than 64 bytes to verify that you have a crash.  Once you verify that this is the problem, you can use the circumvention to get around the crash.  Meanwhile, open an issue and ask for a fix for bug 115280.

I hope that this helps.

P.S.  If you want copies of my simple OpenROAD application that generates dynamic vnodes, just drop me an email.

Durwin Wright | Sr. Architect | Durwin.Wright at ingres.com <mailto:Durwin.Wright at ingres.com>  | Ingres | 500 Arguello Street | Suite 200 | Redwood City | CA | 94063 | USA <http://maps.google.com/maps?q=500+arguello+street,+94063&ll=37.487297,-122.233200&spn=0.004602,0.012771&t=k&hl=en>   +1 650-587-5523 | fax: +1 650-587-5550 

________________________________

From: openroad-users-bounces at peerlessit.com [mailto:openroad-users-bounces at peerlessit.com] On Behalf Of rune.randoy at akerkvaerner.com
Sent: Friday, December 08, 2006 5:56 AM
To: openroad-users at peerlessit.com
Subject: [Openroad-users] vnodeless connection in OpenROAD 4.1 ?

Hi,

I'm trying to connect to a server running Ingres gateways (EA 2.1 0106) without a defined vnode, but with a connection string like this:

@servername,wintcp,II[*,instpwd]::database/mssql

This string works in an sql-command on my PC, queries run ok.

In OpenRoad it connects ok, but OR crashes/exits on first use.

My development environment is OpenROAD 4.1/0403(int.w32/00) (patch 10464).

Anyone had a similar experience? (and fixed it...)

Rune Randøy

Aker Kværner Business Partner (www.akerkvaerner.com)

Kristiansand, Norway

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