[CASSANDRA-11163] Summaries are needlessly rebuilt when the BF FP ratio is changed

• Type: Bug
• Status: Resolved
• Priority: Normal
• Resolution: Fixed
• Fix Version/s: 3.0.17, 3.11.3, 4.0-alpha1, 4.0
• Component/s: Legacy/Core
• Severity: Normal
• Assignee: Kurt Greaves
• Reporter: Brandon Williams

Authors

Kurt Greaves

Reviewers

Chris Lohfink

• Created: 12/Feb/16 00:08
• Updated: 15/May/20 07:59
• Resolved: 12/Mar/18 08:36

Description

This is from trunk, but I also saw this happen on 2.0:

Before:

root@bw-1:/srv/cassandra# ls -ltr /var/lib/cassandra/data/keyspace1/standard1-071efdc0d11811e590c3413ee28a6c90/
total 221460
drwxr-xr-x 2 root root      4096 Feb 11 23:34 backups
-rw-r--r-- 1 root root        80 Feb 11 23:50 ma-6-big-TOC.txt
-rw-r--r-- 1 root root     26518 Feb 11 23:50 ma-6-big-Summary.db
-rw-r--r-- 1 root root     10264 Feb 11 23:50 ma-6-big-Statistics.db
-rw-r--r-- 1 root root   2607705 Feb 11 23:50 ma-6-big-Index.db
-rw-r--r-- 1 root root    192440 Feb 11 23:50 ma-6-big-Filter.db
-rw-r--r-- 1 root root        10 Feb 11 23:50 ma-6-big-Digest.crc32
-rw-r--r-- 1 root root  35212125 Feb 11 23:50 ma-6-big-Data.db
-rw-r--r-- 1 root root      2156 Feb 11 23:50 ma-6-big-CRC.db
-rw-r--r-- 1 root root        80 Feb 11 23:50 ma-7-big-TOC.txt
-rw-r--r-- 1 root root     26518 Feb 11 23:50 ma-7-big-Summary.db
-rw-r--r-- 1 root root     10264 Feb 11 23:50 ma-7-big-Statistics.db
-rw-r--r-- 1 root root   2607614 Feb 11 23:50 ma-7-big-Index.db
-rw-r--r-- 1 root root    192432 Feb 11 23:50 ma-7-big-Filter.db
-rw-r--r-- 1 root root         9 Feb 11 23:50 ma-7-big-Digest.crc32
-rw-r--r-- 1 root root  35190400 Feb 11 23:50 ma-7-big-Data.db
-rw-r--r-- 1 root root      2152 Feb 11 23:50 ma-7-big-CRC.db
-rw-r--r-- 1 root root        80 Feb 11 23:50 ma-5-big-TOC.txt
-rw-r--r-- 1 root root    104178 Feb 11 23:50 ma-5-big-Summary.db
-rw-r--r-- 1 root root     10264 Feb 11 23:50 ma-5-big-Statistics.db
-rw-r--r-- 1 root root  10289077 Feb 11 23:50 ma-5-big-Index.db
-rw-r--r-- 1 root root    757384 Feb 11 23:50 ma-5-big-Filter.db
-rw-r--r-- 1 root root         9 Feb 11 23:50 ma-5-big-Digest.crc32
-rw-r--r-- 1 root root 139201355 Feb 11 23:50 ma-5-big-Data.db
-rw-r--r-- 1 root root      8508 Feb 11 23:50 ma-5-big-CRC.db
root@bw-1:/srv/cassandra# md5sum /var/lib/cassandra/data/keyspace1/standard1-071efdc0d11811e590c3413ee28a6c90/ma-5-big-Summary.db
5fca154fc790f7cfa37e8ad6d1c7552c

BF ratio changed, node restarted:

root@bw-1:/srv/cassandra# ls -ltr /var/lib/cassandra/data/keyspace1/standard1-071efdc0d11811e590c3413ee28a6c90/
total 242168
drwxr-xr-x 2 root root      4096 Feb 11 23:34 backups
-rw-r--r-- 1 root root        80 Feb 11 23:50 ma-6-big-TOC.txt
-rw-r--r-- 1 root root     10264 Feb 11 23:50 ma-6-big-Statistics.db
-rw-r--r-- 1 root root   2607705 Feb 11 23:50 ma-6-big-Index.db
-rw-r--r-- 1 root root    192440 Feb 11 23:50 ma-6-big-Filter.db
-rw-r--r-- 1 root root        10 Feb 11 23:50 ma-6-big-Digest.crc32
-rw-r--r-- 1 root root  35212125 Feb 11 23:50 ma-6-big-Data.db
-rw-r--r-- 1 root root      2156 Feb 11 23:50 ma-6-big-CRC.db
-rw-r--r-- 1 root root        80 Feb 11 23:50 ma-7-big-TOC.txt
-rw-r--r-- 1 root root     10264 Feb 11 23:50 ma-7-big-Statistics.db
-rw-r--r-- 1 root root   2607614 Feb 11 23:50 ma-7-big-Index.db
-rw-r--r-- 1 root root    192432 Feb 11 23:50 ma-7-big-Filter.db
-rw-r--r-- 1 root root         9 Feb 11 23:50 ma-7-big-Digest.crc32
-rw-r--r-- 1 root root  35190400 Feb 11 23:50 ma-7-big-Data.db
-rw-r--r-- 1 root root      2152 Feb 11 23:50 ma-7-big-CRC.db
-rw-r--r-- 1 root root        80 Feb 11 23:50 ma-5-big-TOC.txt
-rw-r--r-- 1 root root     10264 Feb 11 23:50 ma-5-big-Statistics.db
-rw-r--r-- 1 root root  10289077 Feb 11 23:50 ma-5-big-Index.db
-rw-r--r-- 1 root root    757384 Feb 11 23:50 ma-5-big-Filter.db
-rw-r--r-- 1 root root         9 Feb 11 23:50 ma-5-big-Digest.crc32
-rw-r--r-- 1 root root 139201355 Feb 11 23:50 ma-5-big-Data.db
-rw-r--r-- 1 root root      8508 Feb 11 23:50 ma-5-big-CRC.db
-rw-r--r-- 1 root root        80 Feb 12 00:03 ma-8-big-TOC.txt
-rw-r--r-- 1 root root     14902 Feb 12 00:03 ma-8-big-Summary.db
-rw-r--r-- 1 root root     10264 Feb 12 00:03 ma-8-big-Statistics.db
-rw-r--r-- 1 root root   1458631 Feb 12 00:03 ma-8-big-Index.db
-rw-r--r-- 1 root root     10808 Feb 12 00:03 ma-8-big-Filter.db
-rw-r--r-- 1 root root        10 Feb 12 00:03 ma-8-big-Digest.crc32
-rw-r--r-- 1 root root  19660275 Feb 12 00:03 ma-8-big-Data.db
-rw-r--r-- 1 root root      1204 Feb 12 00:03 ma-8-big-CRC.db
-rw-r--r-- 1 root root     26518 Feb 12 00:04 ma-7-big-Summary.db
-rw-r--r-- 1 root root     26518 Feb 12 00:04 ma-6-big-Summary.db
-rw-r--r-- 1 root root    104178 Feb 12 00:04 ma-5-big-Summary.db
root@bw-1:/srv/cassandra# md5sum /var/lib/cassandra/data/keyspace1/standard1-071efdc0d11811e590c3413ee28a6c90/ma-5-big-Summary.db 
5fca154fc790f7cfa37e8ad6d1c7552c 

This hurts startup time and appears to do nothing useful whatsoever.

Issue Links

• causes: CASSANDRA-14387 SSTableReaderTest#testOpeningSSTable fails on macOS
• contains: CASSANDRA-14166 sstabledump tries to delete a file