Code has very little logging

[bzaar]

(Initially raised in #9)

@anjackson, previously we had this requirement for logging:

1. Detailed specification of the back-end URL’s being called should be available in the logs on every request, at DEBUG level.
2. Overall configuration/settings/etc. should be reported at INFO on start up.
3. Any error cases should be reported with stack traces at ERROR level. Exceptions should not be swallowed silently.

We have implemented 1 and 3.

What is implied by 2? Shall we just dump the contents of application.properties to the log file? After removing passwords of course.

When you say "Code has very little logging", how much logging do you expect? It currently logs Solr queries as per (1) above and stack traces as per (3). What else would you like logged?

[anjackson]

Thanks @bzaar - on 1 and 3, I think this was a mistake on my part. The individual classes we were looking at (we didn't look at them all yet) didn't seem to have much logging, but it seems the most important logging is handled elsewhere.

On 2, I think ideally the classes that Spring configures should report those configured values following initialisation. Just dumping the properties file wouldn't mean anything, because it wouldn't prove they'd been picked up by the code.

[anjackson]

There are cases where exceptions can be swallowed silently. These should probably always log the exceptions unless they really cannot ever happen. One example is the IP filtering code which can hide the fact that system properties may be misformatted.