In my previous article I discussed general questions related to network issues in Data Guard due to packet loss and/or retransmissions. Here I’d like to move to discussing specific tools and methodologies for troubleshooting such issues.

Such tools can be broken down by following criteria:

• server-side or network-side
• active or passive
• level of detail they provide (aggregate statistics or individual packet capture).

I think the first item on the list is more or less self-explanatory: there are tools that can be run on the server (either the sender, i.e. production, or the receiver, i.e. the standby), and there are tools that can be run on the network side. The latter aren’t always accessible to the DBA, but sometimes the data from such tools can be made available by the network team via some sort of a graphic user interface, or by request.

Continue reading “Tools for troubleshooting network performance issues” →