Troubleshooting

This section contains topics that describe issues you might encounter and how to resolve them.

See the following topics:

Using Log Files

Providing Diagnostic Information to NuoDB Support

Resolving Management Tier Issues

Resolving Storage Tier Issues

Resolving JDBC Issues

Identifying and Killing Long-Running Queries

In addition, you might find these topics helpful:

As outlined in About Domains, the management tier uses a durable distributed log across all brokers to ensure safety under failure (never returning an incorrect response). If you used NuoDB prior to version 2.1 then you will notice that some information is now stored durably whereas previously a broker's state would be completely removed/reset on restart. Because some configuration information is now durable, you might encounter a situation where you need to remove a process or clean state.

Note: In some situations, logging information that is generated during execution of the SQL EXPLAIN statement might be helpful. For example:
CREATE TABLE t1(a int, b double);
CREATE TABLE t2(a int, b double);
EXPLAIN (opt_log on) SELECT t1.* FRM t1 WHERE t1.a = t2.a;

Output from the EXPLAIN statement when the opt_log option is specified is not guaranteed to be the same from release to release. This output can be used by NuoDB customer support as a debugging tool.