You have seen waits for 'TCP Socket (KGAS)' waits in OEM Grid (or DBConsole) in the ASH (from v$active_session_history) etc. and want to know if this is something to be concerned about.
TCP Socket (KGAS)
A session is waiting for an external host to provide requested data over a network socket. The time that this wait event tracks does not indicate a problem, and even a long wait time is not a reason to contact Oracle Support. It naturally takes time for data to flow between hosts over a network, and for the remote aspect of an application to process any request made to it. An application that communicates with a remote host must wait until the data it will read has arrived. "
The db session cannot proceed to do anything else until the external host provides the requested data over the network socket.
Note: TCP Socket (KGAS) handles direct socket connections. Shared server connections are handled by different code and so will not raise 'TCP Socket (KGAS)' waits
From the database point of view, these waits can safely be ignored; the wait event does not represent a database issue. It merely reports the total elapsed time for a network connection to be established or for data to arrive from over the network. The database waits for the connection to be established and reports the time taken.
From an application or network point of view, delays in establishing a network connection may produce unwanted delays for users. You should make sure that the application makes network calls efficiently and that the network is working well such that these delays are minimised.
NOTE:558510.1 - WAITEVENT: "TCP Socket (KGAS)" Reference Note
Oracle is trying to send a mail message using utl_tcp or utl_smtp, and is having trouble connecting. You probably dont need to worry about it unless there are a lot of Oracle applications that are trying to send emails.
”TCP Socket (Kgas)” Waits Present in 10.2 [ID 416451.1]
The wait event is basically new in version 10.2 and higher. The appearance of the message was discussed in published bug report Bug 5490208. The bottom line is that the event is reporting network performance as follows:
“The db session cannot proceed to do anything else until the external host provides the requested data over the network socket. “
It is reported also that using shared server connections will cause the message to disappear.
BUG:5490208 – TIME WAIT TCP SOCKET KGAS
The wait event is not representing a degrading performance but merely reporting the event as such so it can safely be ignored