Handle invalid date/time format

[thomax]

ES will throw a MapperParsingException and refuse to index a record if a field has strange formatting, e.g.:

"happens_on": ""

will fail. This goes for any field type, not just time/date stamps.

[simen]

The exact reason is that ElasticSearch will guess the type of the field, and other records which have other types of data in the same field will raise this exception. E.g. if you first index this:

{count: 5}

and then later

{count: "Vlad Tepes"}

this will fail, because ElasticSearch thinks counts are integers, not people.

The only solution I can think of currently is to blank offending fields to nil and attempt to reindex so that at least the document gets updated somewhat. We might actually need to add a field to the indexed document to explain what has happened and aid in debugging. So that the evil count would end up something like this:

{count: null, indexing_errors: ["Blanked 'count' which was of a conficting type"]}