Can't return data from SQL/Plus and Toad but can from SQL Developer

This one has me stumped. We are running an Oracle 11g on Amazon EC2 and I can connect and query fine with SQL Developer but with Toad and SQL/Plus I can connect but when I try to do a simple select out of v$session for example it gives me an ORA-03135 after a while. Here is what I have looked at/tried so far (in no particular order):

• Looking in the listener.log file and seeing that all three connect fine

• Turning the windows firewall completely off on the server (nothing changed)

• TNSPing from my machine resolves

• Port scanned to make sure port 1521 was open

• Used telnet to make sure 1521 was open

• Compared listener setup to oracle db on another project

Sounds like the network buffer is being filled but not flushed. SQL*Net performance in this area is often managed by setting tcp.nodelay=yes in sqlnet.ora; also look at the send_buf_size and recv_buf_size parameters.

SQLDev working and not SQLPlus are what pointed me to this type of troubleshooting approach. SQL*Developer uses jdbc behind the scenes to do its fetching.

hth!

StackExchange Database Administrators Q#33748, answer score: 2