Troubleshooting

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

In addition, you might find these topics helpful:

Confirming Domain and Database Status.
Metrics Published by Database Processes describes NuoDB-provided metrics.
Resolving Warnings About Previously Used NuoDB IDs to resolve a Linux installation warning. This section includes information about Determining if Admin Process (AP) Quorum Exists, Handling Unreachable Processes, Removing an Unreachable Admin Server from the Durable Domain, and Re-establishing Admin Process (AP) Quorum.
Re-establishing Admin Process (AP) Quorum for information about identifying situations in which NuoDB cannot automatically recover from a failure.

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.