[OAK-7066] Active deletion blob list files can grow too large due to inlined blobs

• Type: Improvement
• Status: Closed
• Priority: Blocker
• Resolution: Fixed
• Fix Version/s: 1.7.14, 1.8.0
• Component/s: lucene
• Assignee: Vikas Saurabh
• Reporter: Vikas Saurabh
• Created: 14/Dec/17 13:58
• Updated: 08/Oct/19 15:22
• Resolved: 18/Dec/17 10:10

Description

This is follow up from OAK-7052 where we noticed that deleted blob list files collected by active deletion logic can grow very large due to inlined blobs.

One potential way (not sure how yet though) is to not actively delete inlined blobs.

Here are some stats which might help us take a call (based on raw numbers collected at [0])

file-name	large_lines	large_size	small_lines	small_size	small_lines/total_lines	small_size/total_size
blobs-1512664032264.txt	245301	3310224358	173096	35473656	0.413712335413495	0.010602766852107
blobs-1512698405656.txt	370373	4443957885	256775	52997864	0.409432861142824	0.011785275852845
blobs-1512987450004.txt	660669	6214740439	461168	92017554	0.411082893504137	0.014590309966251
blobs-1513130410963.txt	569083	5490965583	406756	80124598	0.416826956085994	0.014382211631264
blobs-1513216819447.txt	69876	1413561892	46238	9221956	0.398212101899857	0.006481628262061

[0]:
file sizes

repository/index/deleted-blobs$ ls -l blobs-151*
-rw-r--r-- 1 root root 3369065620 Dec  8 01:59 blobs-1512664032264.txt
-rw-r--r-- 1 root root 4532250073 Dec  9 01:59 blobs-1512698405656.txt
-rw-r--r-- 1 root root 6370201955 Dec 13 01:59 blobs-1512987450004.txt
-rw-r--r-- 1 root root 1916223582 Dec 13 11:52 blobs-1513130410963.txt

number of entries

repository/index/deleted-blobs$ wc -l blobs-151*
     418397 blobs-1512664032264.txt
     627148 blobs-1512698405656.txt
    1121837 blobs-1512987450004.txt
     308292 blobs-1513130410963.txt
    2475674 total

number of entries and sizes split on threshold of 500 bytes of blob ids

repository/index/deleted-blobs$ for i in blobs-151*;do echo $i;awk 'BEGIN {FS="|"} {len = length($1); if (len > 500) {large++; largeSize+=len} else {small++; smallSize+=len}} END {print large, largeSize, small, smallSize}' $i;done
blobs-1512664032264.txt
245301 3310224358 173096 35473656
blobs-1512698405656.txt
370373 4443957885 256775 52997864
blobs-1512987450004.txt
660669 6214740439 461168 92017554
blobs-1513130410963.txt
569083 5490965583 406756 80124598
blobs-1513216819447.txt
69876 1413561892 46238 9221956

Issue Links

• is related to: OAK-7052 Active deletion purge can OOM if number of blobs listed in a file become too large