RE: Oracle running under Amazon Web services : database connections timing out

OK, thanks for the info
Awaiting more info from client

John
From: Niall Litchfield [mailto:niall.litchfield_at_gmail.com] Sent: 17 April 2018 09:57
To: John Dunn
Subject: Re: Oracle running under Amazon Web services : database connections timing out

The reason for my question is that EC2 is a VM over which the customer has control (and so can access the file system to set sqlnet parameters such as expire_time). RDS is a managed service from AWS where there is no customer access to the host file system. It *appears* that it isn't possible to set sqlnet.expire_time on RDS, but I know that there are Oracle folks on the list who work for AWS who can say definitively if there's an alternative method available to customers.

As far as the behaviour of sqlnet.expire_time itself goes, I don't believe that has *ever* changed. What *is* true is that setting the expire_time higher than 1/2 of the lower of native tcp or firewall timeout may result in the behaviour your customers observe. (the probe packets go every n minutes, but the very first one may be sent anytime up to double the sqlnet.expire_time value).

On Tue, Apr 17, 2018 at 9:33 AM, John Dunn <JDunn_at_sefas.com<mailto:JDunn_at_sefas.com>> wrote: Thanks for replying.

Really don’t know, my knowledge of AWS is non existent.

All I know is the customer moved from a standard Linux server environment into a AWS environment and now the application is experiencing database connection timeouts (apparently after an hour)

Information from customer is sparse(they blame the application, which was previously running fine in a non cloud environment).

As I understand it , with Oracle 11 the behaviour of sqlnet.expire_time is dependent upon other OS tcp timeout settings?

John
From: niall.litchfield_at_gmail.com<mailto:niall.litchfield_at_gmail.com> [mailto:niall.litchfield_at_gmail.com<mailto:niall.litchfield_at_gmail.com>] Sent: 16 April 2018 23:10
To: John Dunn
Subject: Re: Oracle running under Amazon Web services : database connections timing out

It is. But I intended to ask what do you mean by running in AWS? Is this EC2 in which case it's up to you, or RDS in which case I think it isn't (but is enabled with a sensible default) On Mon, 16 Apr 2018, 15:52 John Dunn, <JDunn_at_sefas.com<mailto:JDunn_at_sefas.com>> wrote: Is SQLNET.EXPIRE_TIME available in Oracle 11?

John
From: Norman Dunbar [mailto:oracle_at_dunbar-it.co.uk<mailto:oracle_at_dunbar-it.co.uk>] Sent: 16 April 2018 10:09
To: John Dunn; John Dunn; oracle-l_at_freelists.org<mailto:oracle-l_at_freelists.org> Subject: Re: Oracle running under Amazon Web services : database connections timing out

If I renember correctly, adding SQLNET.EXPIRE_TIME=15 does a probe every 15 minutes to check connections are alive and effectively is a keepalive. I've had to use this in the past. It goes on the server by the way, not the client.

Cheers,
Norm.

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Sent from my Android device with K-9 Mail. Please excuse my brevity.

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Niall Litchfield
Oracle DBA
http://www.orawin.info

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http://www.freelists.org/webpage/oracle-l Received on Tue Apr 17 2018 - 10:59:47 CEST