Nik Everett 83c328f125
Deprecate serializing PipelineAggregators (#54926) (#55025)
`PipelineAggregator`s are only sent across the wire for backwards
compatibility with 7.7.0. `PipelineAggregator` needs to continue to
implement `NamedWriteable` for backwards compatibility but pipeline
aggregations created after 7.7.0 need not implement any of the methods
in that interface because we'll never attempt to call them. So this
creates implementations in `PipelineAggregator` (the base class) that
just throw exceptions.
2020-04-09 14:13:47 -04:00
..