tree 8aeb588c9b8db14d63ce7577b2c515017c2bc65c
parent e01f3009b59a00d81dd1f6d4e807afab08b2d072
author Nick Vatamaniuc <vatamane@apache.org> 1509388883 -0400
committer Joan Touzet <wohali@users.noreply.github.com> 1509504730 -0400

Configurable delay before retrying on missing_doc error

Implement a configurable delay before retrying a document fetch in replicator.

missing_doc exceptions usually happen when there is a continuous replication
set up and the source is updated. The change might appear in the changes feed,
but when worker tries to fetch the document's revisions it talks to a
node where internal replication hasn't caught up and so it throws an exception.

Previously the delay was hard-coded at 0 (that is retrying was immediate). The
replication would still make progress, but after crashing, retrying and
generating a lot of unnecessary log noise. Since updating a source while
continuous replication is running is a common scenario, it's worth optimizing
for it and avoiding wasting resources and spamming logs.