Description

Description of Linked Ticket

The applyOps path for dropIndexes makes an assertion that the primary does not. This can lead to a bug that generates an invalid oplog sequence and causes all secondaries to stop replicating.

There is a bug that can be described by the following sequence in its simplest form:

• Start building an index A
• dropIndexes aborts A and yields its locks
• Start building a new index build on A and commit
• Start building an index B
• dropIndexes reacquires its locks and sees that A is not in progress anymore, so it moves on to replicate a dropIndexes oplog entry instead.
• The secondary sees the dropIndexes oplog entry for A but blocks in the applyOps path because B is still in progress, something that did not happen on the primary.

We need to either a) assert on the primary that no index builds are in progress when a single index is dropped, or b) remove the assertion for the applyOps path.

Scope of changes

Impact to Other Docs

MVP (Work and Date)

Resources (Scope or Design Docs, Invision, etc.)