Incorrect and overflowed db.Metrics().DiskSpaceUsage() #4811
Description
db.Metrics().DiskSpaceUsage() can return an incorrect number which is impossibly large (close to math.Uint64), and appears to be a negative int64 converted to uint64.
db.Metrics().String()
| | | | ingested | moved | written | | amp
level | tables size val-bl vtables | score | in | tables size | tables size | tables size | read | r w
------+-----------------------------+-------+-------+--------------+--------------+--------------+-------+---------
0 | 0 0B 0B 0 | 0.00 | 6.4MB | 0 0B | 0 0B | 7 4.5MB | 0B | 0 0.7
1 | 0 0B 0B 0 | 0.00 | 0B | 0 0B | 0 0B | 0 0B | 0B | 0 0.0
2 | 0 0B 0B 0 | 0.00 | 0B | 0 0B | 0 0B | 0 0B | 0B | 0 0.0
3 | 0 0B 0B 0 | 0.00 | 0B | 0 0B | 0 0B | 0 0B | 0B | 0 0.0
4 | 0 0B 0B 0 | 0.00 | 0B | 0 0B | 0 0B | 0 0B | 0B | 0 0.0
5 | 0 0B 0B 0 | 0.00 | 0B | 0 0B | 0 0B | 0 0B | 0B | 0 0.0
6 | 3 5.1MB 0B 0 | - | 4.5MB | 0 0B | 1 95KB | 6 13MB | 14MB | 1 2.9
total | 3 5.1MB 0B 0 | - | 6.4MB | 0 0B | 1 95KB | 13 24MB | 14MB | 1 3.7
-------------------------------------------------------------------------------------------------------------------
WAL: 1 files (40KB) in: 5.1MB written: 6.4MB (26%!o(MISSING)verhead)
Flushes: 6
Compactions: 6 estimated debt: 0B in progress: 0 (0B)
default: 3 delete: 1 elision: 1 move: 1 read: 0 tombstone-density: 0 rewrite: 0 copy: 0 multi-level: 0
MemTables: 1 (2.0MB) zombie: 1 (2.0MB)
Zombie tables: 0 (0B, local: 0B)
Backing tables: 0 (0B)
Virtual tables: 0 (0B)
Local tables size: 5.1MB
Compression types: none: 3
Block cache: 168 entries (369KB) hit rate: 97.0%!
(MISSING)Table cache: 3 entries (2.2KB) hit rate: 100.0%!
(MISSING)Secondary cache: 0 entries (0B) hit rate: 0.0%!
(MISSING)Snapshots: 0 earliest seq num: 0
Table iters: 0
Filter utility: 98.9%!
(MISSING)Ingestions: 0 as flushable: 0 (0B in 0 tables)
Cgo memory usage: 37MB block cache: 753KB (data: 396KB, maps: 276KB, entries: 80KB) memtables: 36MB
Custom breakdown of public fields used by DiskSpaceUsage
wal phy 1706827 obs phy 1707907
table local live 5313593 obs 18446744073700799630 zombie 0
compact in progress 0
Apparently the table local obsolete size is problematic.
Options used by this db
pebble.Options{
FormatMajorVersion: pebble.FormatColumnarBlocks,
MemTableSize: 2 << 20,
Levels: []pebble.LevelOptions{
{
BlockSize: 2 << 10,
Compression: func() pebble.Compression { return pebble.NoCompression },
FilterPolicy: bloom.FilterPolicy(10),
FilterType: pebble.TableFilter,
},
},
}
Steps to reproduce described in elastic/apm-server#17043
Jira issue: PEBBLE-467