[SOLR-9091] Solr index restore silently copies the corrupt segments in the backup

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Assignee: Unassigned
• Reporter: Hrishikesh Gadre
• Created: 09/May/16 18:28
• Updated: 09/May/16 22:17

Description

The Solr core restore functionality uses following criteria to decide if a given file is copied from backup directory or from current index directory.

case 1] File is available in both backup and current index directory
--> Compare the checksum and file length
--> If checksum and length matching, copy the file from current working directory.
--> If the checksum and length doesn't match, copy the file from backup directory.

case 2] File is available in only in backup directory (This can happen for a newly created core without any data).
--> Copy the file from backup directory.

Now the problem here is that we intentionally catch and ignore the error while reading the checksum for a file in the backup directory. Hence in case (2), it will result into restoration of a file without appropriate "checksum".

Here is the relevant code snippet,
https://github.com/apache/lucene-solr/blob/a5586d29b23f7d032e6d8f0cf8758e56b09e0208/solr/core/src/java/org/apache/solr/handler/RestoreCore.java#L82-L95