Connection time out oracle database with .net core-CodePudding

I have an API that connects with oracle database to execute a function and return value.. suddenly it doesn't work and throws exception "Connection Time out"

CodePudding user response：

Connection timeout is mostly due to firewall issues.

Go to the client machine (who complained) and open a command prompt and try telnet

c:> telnet <hostname.domain) (Port is the database port that your listener is listening on)

For ex,

c:> telnet prodhost.us.oracle.com 1521

and see if it talks. If it doesn't, something (firewall) must be broken since then

CodePudding user response：

connection timeout can also be caused by DB server being extremely busy , you can also try setting the sqlnet parameters to allow for longer connect times as per oracle document shown below :

Oracle Net Services - Version 11.2.0.1 and later Information in this document applies to any platform.Goal This document describes the following sqlnet.ora file parameters:

SQLNET.INBOUND_CONNECT_TIMEOUT=n SQLNET.OUTBOUND_CONNECT_TIMEOUT=n SQLNET.RECV_TIMEOUT=n SQLNET.SEND_TIMEOUT=n TCP.CONNECT_TIMEOUT=n

Note that each parameter is set in seconds.

The default for SQLNET.INBOUND_CONNECT_TIMEOUT is 60 seconds.

The default for TCP.CONNECT_TIMEOUT is also 60 seconds.

There is no default for the remaining parameters.

A setting of 0 for all the parameters above would mean the parameter is "disabled".

The SQLNET.INBOUND_CONNECT_TIMEOUT and SQLNET.OUTBOUND_CONNECT_TIMEOUT parameters are both "connect-time" parameters. If, during the connection phase, the authentication process isn't complete in the amount of time specified by these parameters, the connection will fail. SQLNET.INBOUND_CONNECT_TIMEOUT is strictly a server side parameter. SQLNET.OUTBOUND_CONNECT_TIMEOUT can be used at either client or server to limit the amount of time an outbound connection should be allowed.

The TCP.CONNECT_TIMEOUT controls the amount of time the client is allowed to establish the connection to the server at the TCP layer.
If for example , the resolution of the TCP address given to the client does not complete in the time allowed, the connection will fail with a timeout.

Regarding SQLNET.RECV_TIMEOUT and SQLNET.SEND_TIMEOUT , we can have them both on client and server side. For example, if we have on the server side SQLNET.RECV_TIMEOUT=1 , it means that if the database doesn't receive a request, package exchange in 1 seconds from the client, the connection with that client is terminated,timeout. If SQLNET.SEND_TIMEOUT=1 and if the database cannot complete the send operation to the client in 1 second , the connection is timeout. For example, if the client shutdown abnormally and the information trying to be send by the database receive no answers for 1s , the operation is timeout.