[SOLR-8449] Multiple restores on the same core does not work

• Type: Bug
• Status: Resolved
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 5.2.1, 5.4
• Fix Version/s: 5.5.1, 6.0
• Component/s: replication (java), replication (scripts)
• Labels: Backup/Restore

Environment

SUSE Linux Enterprise Server 11 (64 bit) and Windows 7 Prof SP1

• Assignee: Varun Thacker
• Reporter: Johannes Brucher
• Created: 21/Dec/15 12:40
• Updated: 21/Nov/19 00:41
• Resolved: 22/Apr/16 00:20

Description

Hi all, I facing the following issue with Solr 5.2.1 and the ongoing version 5.4.
The restore functionality is not working under Linux and causing an exception on Windows machines each time you want to restore an existing backup twice or even more.

Steps to reproduce:
1. Start a Solr instance pointing the solr_home to e.g. the example-DIH folder.
2. Select a core, e.g. the “solr” core.
3. Switch to the “Documents” tab
4. Add a document

{“id”:”1”,”title”:”change.me”}

5. Do a backup with the following API call “/solr/replication?command=backup&name=test”
The backup defaults to the location solr_home/solr/data/snapshot.test
6. Add a document to the index

{“id”:”2”,”title”:”change.me”}

. Now there a two document in the index.
7. Restore the back with the following call “/solr/replication?command=restore&name=test”
New index location “solr_home/solr/data/restore.snapshot.test” is created without any physical file in it, except the file write.lock. Num Docs is now 1 as expected!
8. Add a document to the index

{“id”:”3”,”title”:”change.me”}

. Now there a two document in the index.
9. Restore the same previous created back again with the following call “/solr/replication?command=restore&name=test”. Notice, there are still 2 docs in the index!!!
10. Try to restore again, but still the same, 2 docs in the index…
11. Shut down Solr, you will see the index folder “solr_home/solr/data/restore.snapshot.test” disappears.
12. Restart Solr. You will notice the following log entry “Solr index directory ‘solr_home/solr/data/restore.snapshot.test’ doesn’t exist. Creating new index”, and indeed the Index is empty, showing 0 documents.
13. After the restart, I tried to restore the existing backup again without any results…

I thing this behavior in not intended!!!

Even more Problems arise when you run Solr on a Windows machine.
After step 10 a folder “index” is created under “solr_home/solr/data/” with a write.lock file in it. After that, the following exception is thrown:
…Error closing IndexWriter
java.lang.IllegalStateException: file: MMapDirectory@D:\solr\Solr_versions\solr-5.2.1\...restore.snapshot.test lockFactory=org.apache.lucene.store.Nat
iveFSLockFactory@3d3d7a0e appears both in delegate and in cache

The log file from the Windows test is attached.

Let me know if you have problems reproducing the same behavior,

Regards Johannes