Hello.
During the restore of a table using its snapshot and nodetool refresh, I
could see that cassandra starts to make a lot of compactions (depending on
the size of the data).
I wanted to know why and I found this in the code of cassandra 2.1.14.
for CASSANDRA-4872
+ // force foreign sstables to level 0
+ try
+ {
+ if (new
File(descriptor.filenameFor(Component.STATS)).exists())
+ {
+ SSTableMetadata oldMetadata =
SSTableMetadata.serializer.deserialize(descriptor);
+ LeveledManifest.mutateLevel(oldMetadata, descriptor,
descriptor.filenameFor(Component.STATS), 0);
+ }
+ }
+ catch (IOException e)
This is very interesting and I wanted to know if this was coded taking into
account only the case of a migration from STCS to LCS or if for the case
LCS to LCS this is not pertinent
In my case, I use nodetool refresh not only to restore a table but also to
make an exact copy of any table LCS. So I think the levels do not need to
change.
@Marcus Can you be so kind to clarify this for me please ?
Thenk you very much in advance
Best regards
Jean Carlo
"The best way to predict the future is to invent it" Alan Kay
