After recreation of previously dropped SQL index (in persistent mode), root page of new index B+ tree may contain links to data entries from previous index tree. If these entries were removed or relocated to another data page, attempt to dereference these links may throw AssertionError or even cause JVM crash.
Patch with reproducer is attached.
P.S. Please note that with
IGNITE-4958 fix old invalid links may refer to non-data page - it might have been recycled into page with any other type. Such case will cause AssertionError on page read lock attempt. Rolling back IGNITE-4958 may help with debugging.