Update ElasticSearch Document while maintaining its external version the same?

Question

I would like to update an ElasticSearch Document while maintaining the document's version the same. I'm using version_type=external as indicated in the versioning section of the index_ documentation. Updating a document with another of the same version is normally prevented as indicated in that section: "If the value provided is less than or equal to the stored document’s version number, a version conflict will occur and the index operation will fail."

The reason I want to keep the version unaltered is because I do not create a new version of my object (stored in my database) when one adds new tags to that object, but I would like the new tags to show up in my ElasticSearch index. Is this possible with ElasticSearch?

I tried deleting the document and then adding a new document with the same Id and Version but that still gives me the following exception:

VersionConflictEngineException[[myindex][2] [mytype][6]: version conflict, current 1, provided 1]

Just for reference, I'm using PHP Elastica (with methods $type->deleteDocument($doc); and $type->addDocument($doc);) but this question should apply to ElasticSearch in general.

Answer 1

The time for which elasticsearch keeps information about deleted documents is controlled by index.gc_deletes parameter. By default this time is 1m. So, theoretically, you can decrease this time to 0s, wait for a second, delete the document, index a new document with the same version, and set index.gc_deletes back to 1m. But at the moment that would work only on master due to a bug. If you are using older version of elasticsearch, you will not be able to change index.gc_deletes without closing the index first.

There is a good blog post on elasticsearch.org web site that describes how versions are handled by elasticsearch in details.