duplicate "!ttl!x!timestamp|foo" entries causing unwanted deletes

[jfromaniello]

My application does something like:

db.put("foo", "xx", {ttl: ms('1h') });

After sometime running (12hs), I eventually end up with duplicated entries with the key format !ttl!x!timestamp|foo which causes an unwanted delete before the time that is expected to be deleted

I took an snapshot of my db and I ran the following command:

 ./leveldb_keys ~/db-snapshot/ | grep '!ttl!x!' | cut -c 23- | sort | uniq -c | grep -v '^ *1 '
   2 foo
   2 bar
   2 baz

I was having this issue with v2 yesterday (warning it has a different format for the key of these entries). I upgraded to v3 and I continue to have the same problem. If I leave the application running more time I eventually end up having more than 2 of these things. The application didn't crash at any time, etc.

Can you think on any kind of race condition between ttlon/off? Why ttloff might not be working on some circustance?

If someone is using this module in production with traffic, can ran the above command on test if it has duped entries will be awesome.

Thanks

[jfromaniello]

BTW I can't reproduce this issue yet on my tests but I will continue to look into it.

[jfromaniello]

Some more info here:

» ./util/leveldb_keys ~/db-snapshot/ | grep 'foo'
!ttl!x!1459493778475!ÿfoo
!ttl!x!1459516001078!ÿfoo
!ttl!ÿfoo
ÿfoo

» ./util/leveldb_get ~/db-snapshot/ '!ttl!ÿfoo'
'1459516001078'