OpenSearch/core/src
Simon Willnauer d941c64edb
Optimize version map for append-only indexing (#27752)
Today we still maintain a version map even if we only index append-only
or in other words, documents with auto-generated IDs. We can instead maintain
an un-safe version map that will be swapped to a safe version map only if necessary
once we see the first document that requires access to the version map. For instance:
 * a auto-generated id retry
 * any kind of deletes
 * a document with a foreign ID (non-autogenerated

In these cases we forcefully refresh then internal reader and start maintaining
a version map until such a safe map wasn't necessary for two refresh cycles.
Indices / shards that never see an autogenerated ID document will always meintain a version
map and in the case of a delete / retry in a pure append-only index the version map will be
de-optimized for a short amount of time until we know it's safe again to swap back. This
will also minimize the requried refeshes.

Closes #19813
2017-12-15 12:13:10 +01:00
..
main Optimize version map for append-only indexing (#27752) 2017-12-15 12:13:10 +01:00
test Optimize version map for append-only indexing (#27752) 2017-12-15 12:13:10 +01:00